LM22679, LM22679-Q1 LM22679, SNVS581M - FEBRUARY 2013 - REVISED LM22679-Q1 OCTOBER 2020 SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 www.ti.com LM22679/-Q1 42-V, 5-A SIMPLE SWITCHER(R) Step-Down Voltage Regulator With Easy-to-Use Package and load regulation along with high efficiency (> 90%) are featured. Voltage mode control offers short minimum on-time, allowing the widest ratio between input and output voltages. Internal loop compensation means that the user is free from the tedious task of calculating the loop compensation components. Fixed 5-V output and adjustable output voltage options are available. A switching frequency of 500 kHz allows for small external components and good transient response. An adjustable soft-start feature is provided through the selection of a single external capacitor. In addition, the switch-current limit can be programmed with a single external resistor, allowing solution optimization. The LM22679 device also has built-in thermal shutdown and current limiting to protect against accidental overloads. 1 Features * * * * * * * * * * * * * * * New product available: LM61460 3-V to 36-V, 6-A low EMI synchronous converter Wide input voltage range: 4.5 V to 42 V Internally compensated voltage mode control Stable with low-ESR ceramic capacitors 100-m N-channel MOSFET Output voltage options: -ADJ (outputs as low as 1.285 V) -5.0 (output fixed to 5 V) 1.5% feedback reference accuracy Switching frequency of 500 kHz -40C to 125C operating junction temperature range Adjustable soft start Adjustable current limit Integrated bootstrap diode Fully WEBENCH(R) enabled LM22679-Q1 is AEC-Q100 qualified and manufactured on an automotive-grade flow PFM (exposed pad) package The new product, LM61460, offers higher efficiency, lower stand-by quiescent current, and improved EMI performance. See the device comparison table to compare. Start WEBENCH design with LM61460 The LM22679 device is a member of Texas Instruments' SIMPLE SWITCHER(R) family. The SIMPLE SWITCHER concept provides for an easy to use complete design using a minimum number of external components and the TI WEBENCH design tool. TI's WEBENCH tool includes features such as external component calculation, electrical simulation, thermal simulation, and Build-It boards for easy design-in. 2 Applications * * * * Industrial distributed power applications Test and measurement Appliances General-purpose wide VIN applications Device Information 3 Description The LM22679 switching regulator provides all of the functions necessary to implement an efficient highvoltage step-down (buck) regulator using a minimum of external components. This easy-to-use regulator incorporates a 42-V N-channel MOSFET switch that can provide up to 5 A of load current. Excellent line PART NUMBER LM22679 LM22679-Q1 (1) PACKAGE(1) TO-263 (7) BODY SIZE (NOM) 10.16 mm x 9.85 mm For all available packages, see the orderable addendum at the end of the data sheet. VIN VIN FB LM22679-ADJ BOOT VOUT SW IADJ SS GND Simplified Application Schematic An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated intellectual property matters and other important disclaimers. PRODUCTION DATA. Product Folder Links: LM22679 LM22679-Q1 1 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 Table of Contents 1 Features............................................................................1 2 Applications..................................................................... 1 3 Description.......................................................................1 4 Revision History.............................................................. 2 5 Pin Configuration and Functions...................................3 Pin Functions.................................................................... 3 6 Specifications.................................................................. 4 6.1 Absolute Maximum Ratings........................................ 4 6.2 Handling Ratings: LM22679........................................4 6.3 Handling Ratings: LM22679-Q1..................................4 6.4 Recommended Operating Conditions.........................4 6.5 Thermal Information....................................................4 6.6 Electrical Characteristics.............................................5 6.7 Typical Characteristics................................................ 6 7 Detailed Description........................................................8 7.1 Overview..................................................................... 8 7.2 Functional Block Diagram........................................... 8 7.3 Feature Description.....................................................9 7.4 Device Functional Modes..........................................10 8 Application and Implementation.................................. 14 8.1 Application Information............................................. 14 8.2 Typical Application.................................................... 15 9 Power Supply Recommendations................................19 10 Layout...........................................................................20 10.1 Layout Guidelines................................................... 20 10.2 Layout Example...................................................... 21 10.3 Thermal Considerations..........................................22 11 Device and Documentation Support..........................23 11.1 Documentation Support.......................................... 23 11.2 Support Resources................................................. 23 11.3 Receiving Notification of Documentation Updates.. 23 11.4 Trademarks............................................................. 23 11.5 Glossary.................................................................. 23 11.6 Electrostatic Discharge Caution.............................. 23 4 Revision History Changes from Revision L (November 2014) to Revision M (October 2020) Page * Added LM61460 bullet to the Features ..............................................................................................................1 * Updated the numbering format for tables, figures and cross-references throughout the document...................1 Changes from Revision K (March 2013) to Revision L (November 2014) Page * Added Pin Configuration and Functions section, Handling Rating tables, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section ............................................................................................................................................................... 1 * Deleted Inverting Regulator Application .......................................................................................................... 14 2 Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 5 Pin Configuration and Functions 7 SS 6 FB 5 IADJ 4 GND 3 BOOT 2 VIN 1 SW Exposed Pad Connect to GND Figure 5-1. 7-Pin NDR Package Top View Pin Functions PIN NAME NO. TYPE DESCRIPTION APPLICATION INFORMATION SW 1 O Switch Output Switching output of regulator VIN 2 I Input Voltage Supply input to regulator BOOT 3 I Bootstrap input Provides the gate voltage for the high side NFET Ground input to regulator; system common System ground pin GND 4 -- IADJ 5 I Current limit adjust input pin A resistor attached between this pin and GND can be used to set the current limit threshold. Pin can be left floating and internal setting will be default. FB 6 I Feedback Input Feedback input to regulator SS 7 O Soft-start pin Used to increase soft-start time. See Section 7.3.2. EP EP -- Exposed Pad Connect to ground. Provides thermal connection to PCB. See Section 8. Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 3 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 6 Specifications 6.1 Absolute Maximum Ratings MIN MAX VIN to GND SS, IADJ Pin Voltage SW to GND(1) V -0.5 7 V -5 VIN V VSW + 7 V 7 V 150 C Boot Pin Voltage FB Pin Voltage -0.5 Power Dissipation Internally Limited Junction Temperature(2) (1) (2) UNIT 43 The absolute-maximum specification of the `SW to GND' applies to dc voltage. An extended negative voltage limit of -10 V applies to a pulse of up to 50 ns. For soldering specifications, refer to refer to application report Absolute Maximum Ratings for Soldering (SNOA549). 6.2 Handling Ratings: LM22679 Tstg Storage temperature range V(ESD) Electrostatic discharge (1) Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins(1) MIN MAX UNIT -65 150 C -2 2 kV JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. 6.3 Handling Ratings: LM22679-Q1 Tstg Storage temperature range V(ESD) (1) Electrostatic discharge Human body model (HBM), per AEC Q100-002(1) MIN MAX UNIT -65 150 C -2 2 kV AEC Q100-002 indicates HBM stressing is done in accordance with the ANSI/ESDA/JEDEC JS-001 specification. 6.4 Recommended Operating Conditions over operating free-air temperature range (unless otherwise noted) VIN MIN MAX Supply Voltage 4.5 42 UNIT V Junction Temperature Range -40 125 C 6.5 Thermal Information LM22679 THERMAL METRIC(1) (2) NDR UNIT 7 PINS RJA (1) (2) 4 Junction-to-ambient thermal resistance 22 C/W For more information about traditional and new thermal metrics, see the application report IC Package Thermal Metrics (SPRA953). The value of RJA for the PFM (TJ) package of 22C/W is valid if package is mounted to 1 square inch of copper. The RJA value can range from 20 to 30C/W depending on the amount of PCB copper dedicated to heat transfer. See application note AN-1797 TO-263 THIN Package (SNVA328) for more information. Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 6.6 Electrical Characteristics Typical values represent the most likely parametric norm at TA = TJ = 25C, and are provided for reference purposes only. Unless otherwise specified: VIN = 12 V. PARAMETER TEST CONDITIONS MIN(1) TYP(2) MAX(1) 4.925 5.0 5.075 UNIT LM22679-5.0 VFB Feedback Voltage VIN = 8 V to 42 V VIN = 8 V to 42 V, -40C TJ 125C 4.9 5.1 V LM22679-ADJ VFB Feedback Voltage VIN = 4.7 V to 42 V 1.266 VIN = 4.7 V to 42 V, -40C TJ 125C 1.259 1.285 1.304 1.311 V ALL OUTPUT VOLTAGE VERSIONS IQ Quiescent Current VADJ Current Limit Adjust Voltage VFB = 5 V 3.4 VFB = 5 V, -40C TJ 125C 6 mA 0.8 0.65 0.9 V -40C TJ 125C ICL Current Limit IL Output Leakage Current RDS(ON) Switch On-Resistance fO Oscillator Frequency TOFFMIN Minimum Off-time TONMIN Minimum On-time IBIAS Feedback Bias Current ISS Soft-start Current TSD Thermal Shutdown Threshold (1) (2) 6.0 -40C TJ 125C 7.1 5.75 VIN = 42 V, SS Pin = 0 V, VSW = 0 V 8.75 32 VSW = -1 V 8.4 60 A 31 75 A 0.10 0.14 0.2 500 -40C TJ 125C 400 600 200 -40C TJ 125C 100 VFB = 1.3 V (ADJ Version Only) 300 kHz ns 100 ns 230 nA 50 -40C TJ 125C A 30 70 150 A C MIN and MAX limits are 100% production tested at 25C. Limits over the operating temperature range are ensured through correlation using Statistical Quality Control (SQC) methods. Limits are used to calculate TI's Average Outgoing Quality Level (AOQL). Typical values represent most likely parametric norms at the conditions specified and are not ensured. Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 5 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 6.7 Typical Characteristics Vin = 12 V, TJ = 25C (unless otherwise specified) 6 Figure 6-1. Efficiency vs IOUT and VIN (VOUT = 3.3 V) Figure 6-2. Current Limit vs Temperature Figure 6-3. Normalized Switching Frequency vs Temperature Figure 6-4. Feedback Bias Current vs Temperature Figure 6-5. Normalized Feedback Voltage vs Temperature Figure 6-6. Normalized RDS(ON) vs Temperature Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 Figure 6-7. Normalized Feedback Voltage vs Input Voltage Figure 6-8. Soft-Start Current vs Temperature Figure 6-9. Current Limit vs IADJ Resistor Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 7 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 7 Detailed Description 7.1 Overview The LM22679 incorporates a voltage mode constant frequency PWM architecture. In addition, input voltage feedforward is used to stabilize the loop gain against variations in input voltage. This allows the loop compensation to be optimized for transient performance. The power MOSFET, in conjunction with the diode, produces a rectangular waveform at the switch pin, that swings from about zero volts to VIN. The inductor and output capacitor average this waveform to become the regulator output voltage. By adjusting the duty cycle of this waveform, the output voltage can be controlled. The error amplifier compares the output voltage with the internal reference and adjusts the duty cycle to regulate the output at the desired value. The internal loop compensation of the -ADJ option is optimized for outputs of 5 V and below. If an output voltage of 5 V or greater is required, the -5.0 option can be used with an external voltage divider. The minimum output voltage is equal to the reference voltage, that is, 1.285 V (typ). 7.2 Functional Block Diagram VIN VIN BOOT Vcc INT REG, EN, UVLO ILimit IADJ FB TYPE III COMP + PWM Cmp. + - LOGIC Error Amp. VOUT SW OSC 1.285V & Soft-start SS 8 GND Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 www.ti.com LM22679, LM22679-Q1 SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 7.3 Feature Description 7.3.1 UVLO The LM22679 also incorporates an input undervoltage lock-out (UVLO) feature. This prevents the regulator from turning on when the input voltage is not great enough to properly bias the internal circuitry. The rising threshold is 4.3 V (typ) while the falling threshold is 3.9 V (typ). 7.3.2 Soft-Start The soft-start feature allows the regulator to gradually reach steady-state operation, thus reducing start-up stresses. The internal soft-start feature brings the output voltage up in about 500 s. This time can be extended by using an external capacitor connected to the SS pin. Values in the range of 100 nF to 1 F are recommended. The approximate soft-start time can be estimated from Equation 1. TSS 26 x 103 x CSS (1) Soft-start is reset any time the part is shut down or a thermal overload event occurs. 7.3.3 Bootstrap Supply The LM22679 device incorporates a floating high-side gate driver to control the power MOSFET. The supply for this driver is the external boot-strap capacitor connected between the BOOT pin and SW. A good quality 10-nF ceramic capacitor must be connected to these pins with short, wide PCB traces. One reason the regulator imposes a minimum off-time is to ensure that this capacitor recharges every switching cycle. A minimum load of about 5 mA is required to fully recharge the bootstrap capacitor in the minimum off-time. Some of this load can be provided by the output voltage divider, if used. 7.3.4 Internal Compensation The LM22679 device has internal loop compensation designed to provide a stable regulator over a wide range of external power stage components. The internal compensation of the -ADJ option is optimized for output voltages below 5 V. If an output voltage of 5 V or greater is needed, the -5.0 option with an external resistor divider can be used. Ensuring stability of a design with a specific power stage (inductor and output capacitor) can be tricky. The LM22679 stability can be verified using the WEBENCH Designer online circuit simulation tool. A quick start spreadsheet can also be downloaded from the online product folder. The complete transfer function for the regulator loop is found by combining the compensation and power stage transfer functions. The LM22679 has internal type III loop compensation, as detailed in Internal Loop Compensation section. This is the approximate "straight line" function from the FB pin to the input of the PWM modulator. The power stage transfer function consists of a dc gain and a second order pole created by the inductor and output capacitor or capacitors. Due to the input voltage feedforward employed in the LM22679, the power stage dc gain is fixed at 20 dB. The second order pole is characterized by its resonant frequency and its quality factor (Q). For a first pass design, the product of inductance and output capacitance should conform to Equation 2. (2) Alternatively, this pole should be placed between 1.5 kHz and 15 kHz and is given by Equation 3. (3) The Q factor depends on the parasitic resistance of the power stage components and is not typically in the control of the designer. Of course, loop compensation is only one consideration when selecting power stage components (see Section 8 for more details). Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 9 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 COMPENSATOR GAIN (dB) 40 35 -ADJ -5.0 30 25 20 15 10 5 0 100 1k 10k 100k 1M FREQUENCY (Hz) 10M Figure 7-1. Compensator Gain In general, hand calculations or simulations can only aid in selecting good power stage components. Good design practice dictates that load and line transient testing should be done to verify the stability of the application. Also, Bode plot measurements should be made to determine stability margins. The AN-1889 How to Measure the Loop Transfer Function of Power Supplies application report (SNVA364) shows how to perform a loop transfer function measurement with only an oscilloscope and function generator. 7.4 Device Functional Modes 7.4.1 Shutdown Mode The LM22679 device incorporates an input undervoltage lock-out (UVLO) feature. This prevents the regulator from turning on when the input voltage is not great enough to properly bias the internal circuitry. The rising threshold is 4.3 V (typ) while the falling threshold is 3.9 V (typ). 7.4.2 Active Mode The LM22679 is in Active Mode when VIN is above its UVLO level. See Section 7.3.1 for more information on the UVLO level. 7.4.3 Current Limit The LM22679 device has current limiting to prevent the switch current from exceeding safe values during an accidental overload on the output. This peak current limit is found in Section 6.6 under the heading of I CL. The maximum load current that can be provided, before current limit is reached, is determined from Equation 4. (4) where * L is the value of the power inductor When the LM22679 enters current limit, the output voltage will drop and the peak inductor current will be fixed at I CL at the end of each cycle. The switching frequency will remain constant while the duty cycle drops. The load current will not remain constant, but will depend on the severity of the overload and the output voltage. For very severe overloads ("short-circuit"), the regulator changes to a low frequency current foldback mode of operation. The frequency foldback is about 1/5 of the nominal switching frequency. This will occur when the current limit trips before the minimum on-time has elapsed. This mode of operation is used to prevent inductor current "run-away", and is associated with very low output voltages when in overload. Equation 5 can be used to determine what level of output voltage will cause the part to change to low frequency current foldback. (5) where 10 Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 LM22679, LM22679-Q1 www.ti.com * * SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 Fsw is the normal switching frequency Vin is the maximum for the application If the overload drives the output voltage to less than or equal to Vx, the part will enter current foldback mode. If a given application can drive the output voltage to V x, during an overload, then a second criterion must be checked. Equation 6 gives the maximum input voltage, when in this mode, before damage occurs. (6) where * * Vsc is the value of output voltage during the overload fsw is the normal switching frequency Note If the input voltage should exceed this value, while in foldback mode, the regulator, the diode can be damaged, or both. It is important to note that the voltages in these equations are measured at the inductor. Normal trace and wiring resistance will cause the voltage at the inductor to be higher than that at a remote load. Therefore, even if the load is shorted with zero volts across its terminals, the inductor will still see a finite voltage. It is this value that should be used for V x and V sc in the calculations. In order to return from foldback mode, the load must be reduced to a value much lower than that required to initiate foldback. This load "hysteresis" is a normal aspect of any type of current limit foldback associated with voltage regulators. The safe operating area, when in short circuit mode, is shown in Figure 7-2. Operating points below and to the right of the curve represent safe operation. 45 INPUT VOLTAGE (v) 40 35 30 25 SAFE OPERATING AREA 20 15 10 5 0.0 0.2 0.4 0.6 0.8 1.0 SHORT CIRCUIT VOLTAGE (v) 1.2 Figure 7-2. SOA Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 11 LM22679, LM22679-Q1 SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 www.ti.com 7.4.4 Current Limit Adjustment A key feature of the LM22679 device is the ability to adjust the peak switch current limit. This can be useful when the full current capability of the regulator is not required for a given application. A smaller current limit may allow the use of power components with lower current ratings, thus saving space and reducing cost. A single resistor between the IADJ pin and ground controls the current limit in accordance with Figure 7-3. The current limit mode is set during start-up of the regulator. When VIN is applied, a weak pullup is connected to the IADJ pin and, after approximately 100 s, the voltage on the pin is checked against a threshold of about 0.8 V. With the IADJ pin open, the voltage floats above this threshold, and the current limit is set to the default value of 7.1 A (typ). With a resistor present, an internal reference holds the pin voltage at 0.8 V; thus, the resulting current sets the current limit. The accuracy of the adjusted current limit will be slightly worse than that of the default value; +35% / -25% is to be expected. Resistor values should not exceed the limits shown in Figure 7-3. Figure 7-3. Current Limit vs IADJ Resistor 7.4.5 Thermal Protection Internal thermal shutdown circuitry protects the LM22679 device, should the maximum junction temperature be exceeded. This protection is activated at about 150C, with the result that the regulator will shut down until the temperature drops below about 135C. 7.4.6 Duty-Cycle Limits Ideally the regulator would control the duty cycle over the full range of zero to one. However due to inherent delays in the circuitry, there are limits on both the maximum and minimum duty cycles that can be reliably controlled. This in turn places limits on the maximum and minimum input and output voltages that can be converted by the LM22679. A minimum on-time is imposed by the regulator in order to correctly measure the switch current during a current limit event. A minimum off-time is imposed in order the re-charge the bootstrap capacitor. Equation 7 can be used to determine the approximate maximum input voltage for a given output voltage. (7) where * * Fsw is the switching frequency TON is the minimum on-time Both parameters are found in Section 6.6. Nominal values should be used. The worst case is lowest output voltage. If this input voltage is exceeded, the regulator will skip cycles, effectively lowering the switching frequency. The consequences of this are higher output voltage ripple and a degradation of the output voltage accuracy. 12 Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 The second limitation is the maximum duty cycle before the output voltage will "dropout" of regulation. Equation 8 can be used to approximate the minimum input voltage before dropout occurs: where (8) * The values of TOFF and RDS(ON) are found in Section 6.6. The worst case here is largest load. In this equation, RL is the dc inductor resistance. Of course, the lowest input voltage to the regulator must not be less than 4.5 V (typ). Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 13 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 8 Application and Implementation Note Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI's customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality. 8.1 Application Information The LM22679 device is a step down dc-to-dc regulator. It is typically used to convert a higher dc voltage to a lower dc voltage with a maximum output current of 5 A. The following design procedure can be used to select components for the LM22679. Alternately, the WEBENCH software may be used to generate complete designs. When generating a design, the WEBENCH software utilizes iterative design procedure and accesses comprehensive databases of components. Go to WEBENCH Designer for more details. This section presents a simplified discussion of the design process. 8.1.1 Output Voltage Divider Selection For output voltages between about 1.285 V and 5 V, the -ADJ option should be used, with an appropriate voltage divider as shown in Figure 8-1. Equation 9 can be used to calculate the resistor values of this divider. (9) A good value for R FBB is 1 k. This will help to provide some of the minimum load current requirement and reduce susceptibility to noise pick-up. The top of R FBT should be connected directly to the output capacitor or to the load for remote sensing. If the divider is connected to the load, a local high-frequency bypass should be provided at that location. For output voltages of 5 V, the -5.0 option should be used. In this case no external divider is needed and the FB pin is connected to the output. The approximate values of the internal voltage divider are as follows: 7.38 k from the FB pin to the input of the error amplifier and 2.55 k from there to ground. Both the -ADJ and -5.0 options can be used for output voltages greater than 5 V, by using the correct output divider. As mentioned in Section 7.3.4, the -5.0 option is optimized for output voltages of 5V. However, for output voltages greater than 5 V, this option may provide better loop bandwidth than the -ADJ option, in some applications. If the -5.0 option is to be used at output voltages greater than 5 V, Equation 10 should be used to determine the resistor values in the output divider: (10) A value of RFBB of about 1 k is a good first choice. Vout RFBT FB RFBB Figure 8-1. Resistive Feedback Divider 14 Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 A maximum value of 10 k is recommended for the sum of R FBB and R FBT to maintain good output voltage accuracy for the -ADJ option. A maximum of 2 k is recommended for the -5.0 option. For the -5.0 option, the total internal divider resistance is typically 9.93 k. In all cases, the output voltage divider should be placed as close as possible to the FB pin of the LM22679, because this is a high impedance input and is susceptible to noise pick-up. 8.1.2 Power Diode A Schottky-type power diode is required for all LM22679 applications. Ultra-fast diodes are not recommended and may result in damage to the IC due to reverse recovery current transients. The near ideal reverse recovery characteristics and low forward voltage drop of Schottky diodes are particularly important for high input voltage and low output voltage applications common to the LM22679 device. The reverse breakdown rating of the diode should be selected for the maximum VIN, plus some safety margin. A good rule of thumb is to select a diode with a reverse voltage rating of 1.3 times the maximum input voltage. Select a diode with an average current rating at least equal to the maximum load current that will be seen in the application. 8.2 Typical Application 8.2.1 Typical Buck Regulator Application Figure 8-2 shows an example of converting an input voltage range of 5.5 V to 42 V, to an output of 3.3 V at 5 A. RFBB 976: VIN 4.5V to 42V C2 22 PF + C1 6.8 PF C7 6.8 PF C6 1 PF FB VIN C3 LM22679-ADJ 10 nF SS BOOT IADJ R3 GND RFBT 1.54 k: L1 4.7 PH SW VOUT 3.3V D1 60V, 5A C4 180 PF GND + GND Figure 8-2. Typical Buck Regulator Application 8.2.1.1 Design Requirements DESIGN PARAMETERS EXAMPLE VALUE Driver Supply Voltage (VIN) 5.5 to 42 V Output Voltage (VOUT) 3.3 V RFBT Calculated based on RFBB and VREF of 1.285 V. RFBB 1 k to 10 k IOUT 5A 8.2.1.2 Detailed Design Procedure 8.2.1.2.1 External Components The following guidelines should be used when designing a step-down (buck) converter with the LM22679. 8.2.1.2.2 Inductor The inductor value is determined based on the load current, ripple current, and the minimum and maximum input voltages. To keep the application in continuous conduction mode (CCM), the maximum ripple current, I RIPPLE, should be less than twice the minimum load current. The general rule of keeping the inductor current peak-to-peak ripple around 30% of the nominal output current is a good compromise between excessive output voltage ripple and excessive component size and cost. Using this value of ripple current, the value of inductor, L, is calculated using Equation 11. Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 15 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 (11) where * * Fsw is the switching frequency Vin should be taken at its maximum value, for the given application The formula in Equation 11 provides a guide to select the value of the inductor L; the nearest standard value will then be used in the circuit. Once the inductor is selected, the actual ripple current can be found from Equation 12. (12) Increasing the inductance will generally slow down the transient response but reduce the output voltage ripple. Reducing the inductance will generally improve the transient response but increase the output voltage ripple. The inductor must be rated for the peak current, I PK, in a given application, to prevent saturation. During normal loading conditions, the peak current is equal to the load current plus 1/2 of the inductor ripple current. During an overload condition, as well as during certain load transients, the controller may trip current limit. In this case the peak inductor current is given by I CL, found in Section 6.6. Good design practice requires that the inductor rating be adequate for this overload condition. Note If the inductor is not rated for the maximum expected current, it can saturate resulting in damage to the LM22679, the power diode, or both. This consideration highlights the value of the current limit adjust feature of the LM22679. 8.2.1.2.3 Input Capacitor The input capacitor selection is based on both input voltage ripple and RMS current. Good quality input capacitors are necessary to limit the ripple voltage at the VIN pin while supplying most of the regulator current during switch on-time. Low-ESR ceramic capacitors are preferred. Larger values of input capacitance are desirable to reduce voltage ripple and noise on the input supply. This noise may find its way into other circuitry, sharing the same input supply, unless adequate bypassing is provided. A very approximate formula for determining the input voltage ripple is shown in Equation 13. (13) where * Vri is the peak-to-peak ripple voltage at the switching frequency Another concern is the RMS current passing through this capacitor. Equation 14 determines an approximation to this current. (14) The capacitor must be rated for at least this level of RMS current at the switching frequency. 16 Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 www.ti.com LM22679, LM22679-Q1 SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 All ceramic capacitors have large voltage coefficients, in addition to normal tolerances and temperature coefficients. To help mitigate these effects, multiple capacitors can be used in parallel to bring the minimum capacitance up to the desired value. This may also help with RMS current constraints by sharing the current among several capacitors. Many times it is desirable to use an electrolytic capacitor on the input, in parallel with the ceramics. The moderate ESR of this capacitor can help to damp any ringing on the input supply caused by long power leads. This method can also help to reduce voltage spikes that can exceed the maximum input voltage rating of the LM22679. It is good practice to include a high frequency bypass capacitor as close as possible to the LM22679. This small case size, low ESR, ceramic capacitor should be connected directly to the VIN and GND pins with the shortest possible PCB traces. Values in the range of 0.47 F to 1 F are appropriate. This capacitor helps to provide a low impedance supply to sensitive internal circuitry. It also helps to suppress any fast noise spikes on the input supply that can lead to increased EMI. 8.2.1.2.4 Output Capacitor The output capacitor is responsible for filtering the output voltage and supplying load current during transients. Capacitor selection depends on application conditions as well as ripple and transient requirements. Best performance is achieved with a parallel combination of ceramic capacitors and a low ESR SPTM or POSCAPTM types. Very low ESR capacitors such as ceramics reduce the output ripple and noise spikes, while higher value electrolytics or polymers provide large bulk capacitance to supply transients. Assuming very low ESR, Equation 15 gives an approximation to the output voltage ripple: (15) Typically, a total value of 100 F or greater is recommended for output capacitance. In applications with V out less than 3.3 V, it is critical that low ESR output capacitors are selected. This will limit potential output voltage overshoots as the input voltage falls below the device normal operating range. 8.2.1.2.5 Bootstrap Capacitor The bootstrap capacitor between the BOOT pin and the SW pin supplies the gate current to turn on the Nchannel MOSFET. The recommended value of this capacitor is 10 nF and should be a good quality, low-ESR ceramic capacitor. In some cases, it can be desirable to slow down the turn-on of the internal power MOSFET to reduce EMI. This can be done by placing a small resistor in series with the C boot capacitor. Resistors in the range of 10 to 50 can be used. This technique should only be used when absolutely necessary, because it will increase switching losses and thereby reduce efficiency. Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 17 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 8.2.1.3 Application Curve Figure 8-3. Efficiency vs IOUT and VIN (VOUT = 3.3 V) 18 Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 9 Power Supply Recommendations The LM22679 device is designed to operate from an input voltage supply range between 4.5 V and 42 V. This input supply should be well regulated and able to withstand maximum input current and maintain a stable voltage. The resistance of the input supply rail should be low enough that an input current transient does not cause a high enough drop at the LM22679 supply voltage that can cause a false UVLO fault triggering and system reset. If the input supply is located more than a few inches from the LM22679 additional bulk capacitance may be required in addition to the ceramic bypass capacitors. The amount of bulk capacitance is not critical, but a 47-F or 100-F electrolytic capacitor is a typical choice. Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 19 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 10 Layout 10.1 Layout Guidelines Board layout is critical for the proper operation of switching power supplies. First, the ground plane area must be sufficient for thermal dissipation purposes. Second, appropriate guidelines must be followed to reduce the effects of switching noise. Switch mode converters are very fast switching devices. In such cases, the rapid increase of input current combined with the parasitic trace inductance generates unwanted L di/dt noise spikes. The magnitude of this noise tends to increase as the output current increases. This noise may turn into electromagnetic interference (EMI) and can also cause problems in device performance. Therefore, care must be taken in layout to minimize the effect of this switching noise. The most important layout rule is to keep the ac current loops as small as possible. Figure 10-1 shows the current flow in a buck converter. The top schematic shows a dotted line which represents the current flow during the FET switch on-state. The middle schematic shows the current flow during the FET switch off-state. The bottom schematic shows the currents referred to as ac currents. These ac currents are the most critical because they are changing in a very short time period. The dotted lines of the bottom schematic are the traces to keep as short and wide as possible. This will also yield a small loop area reducing the loop inductance. To avoid functional problems due to layout, review the PCB layout example. Best results are achieved if the placement of the LM22679, the bypass capacitor, the Schottky diode, R FBB, R FBT, and the inductor are placed as shown in Figure 10-2. In the layout shown, R1 = R FBB and R2 = R FBT. It is also recommended to use 2 oz copper boards or heavier to help thermal dissipation and to reduce the parasitic inductances of board traces. See AN-1229 SIMPLE SWITCHER (R) PCB Layout Guidelines (SNVA054) for more information. Figure 10-1. Current Flow in a Buck Application 20 Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 www.ti.com LM22679, LM22679-Q1 SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 10.2 Layout Example Figure 10-2. LM22679 Layout Example Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 21 LM22679, LM22679-Q1 SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 www.ti.com 10.3 Thermal Considerations The components with the highest power dissipation are the power diode and the power MOSFET internal to the LM22679 regulator. The easiest method to determine the power dissipation within the LM22679 is to measure the total conversion losses then subtract the power losses in the diode and inductor. The total conversion loss is the difference between the input power and the output power. An approximation for the power diode loss is shown in Equation 16. (16) where * VD is the diode voltage drop An approximation for the inductor power is shown in Equation 17. (17) where * * RL is the dc resistance of the inductor The 1.1 factor is an approximation for the ac losses The regulator has an exposed thermal pad to aid power dissipation. Adding multiple vias under the device to the ground plane will greatly reduce the regulator junction temperature. Selecting a diode with an exposed pad will also aid the power dissipation of the diode. The most significant variables that affect the power dissipation of the regulator are output current, input voltage and operating frequency. The power dissipated while operating near the maximum output current and maximum input voltage can be appreciable. The junction-to-ambient thermal resistance of the LM22679 will vary with the application. The most significant variables are the area of copper in the PC board, the number of vias under the IC exposed pad and the amount of forced air cooling provided. A large continuos ground plane on the top or bottom PCB layer will provide the most effective heat dissipation. The integrity of the solder connection from the IC exposed pad to the PC board is critical. Excessive voids will greatly diminish the thermal dissipation capacity. The junction-to-ambient thermal resistance of the LM22679 PFM package is specified in Section 6.6. See AN-2020 Thermal Design By Insight, Not Hindsight (SNVA419) for more information. 22 Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 LM22679, LM22679-Q1 www.ti.com SNVS581M - FEBRUARY 2013 - REVISED OCTOBER 2020 11 Device and Documentation Support 11.1 Documentation Support 11.1.1 Related Documentation * * * * AN-2020 Thermal Design By Insight, Not Hindsight (SNVA419) AN-1229 SIMPLE SWITCHER (R) PCB Layout Guidelines (SNVA054) AN-1891 LM22679 Evaluation Board (SNVA365) AN-1889 How to Measure the Loop Transfer Function of Power Supplies (SNVA364) 11.2 Support Resources TI E2ETM support forums are an engineer's go-to source for fast, verified answers and design help -- straight from the experts. Search existing answers or ask your own question to get the quick design help you need. Linked content is provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. 11.3 Receiving Notification of Documentation Updates To receive notification of documentation updates, navigate to the device product folder on ti.com. Click on Subscribe to updates to register and receive a weekly digest of any product information that has changed. For change details, review the revision history included in any revised document. 11.4 Trademarks TI E2ETM is a trademark of Texas Instruments. WEBENCH(R) and SIMPLE SWITCHER(R) are registered trademarks of Texas Instruments. All other trademarks are the property of their respective owners. 11.5 Glossary TI Glossary This glossary lists and explains terms, acronyms, and definitions. 11.6 Electrostatic Discharge Caution This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation. Submit Document Feedback Copyright (c) 2020 Texas Instruments Incorporated Product Folder Links: LM22679 LM22679-Q1 23 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (C) Device Marking (3) (4/5) (6) LM22679QTJ-5.0/NOPB ACTIVE TO-263 NDR 7 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 LM22679 QTJ-5.0 LM22679QTJ-ADJ/NOPB ACTIVE TO-263 NDR 7 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 LM22679 QTJ-ADJ LM22679QTJE-5.0/NOPB ACTIVE TO-263 NDR 7 250 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 LM22679 QTJ-5.0 LM22679QTJE-ADJ/NOPB ACTIVE TO-263 NDR 7 250 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 LM22679 QTJ-ADJ LM22679TJ-5.0/NOPB ACTIVE TO-263 NDR 7 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 LM22679 TJ-5.0 LM22679TJ-ADJ/NOPB ACTIVE TO-263 NDR 7 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 LM22679 TJ-ADJ LM22679TJE-5.0/NOPB ACTIVE TO-263 NDR 7 250 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 LM22679 TJ-5.0 LM22679TJE-ADJ/NOPB ACTIVE TO-263 NDR 7 250 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 LM22679 TJ-ADJ (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based flame retardants must also meet the <=1000ppm threshold requirement. (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. OTHER QUALIFIED VERSIONS OF LM22679, LM22679-Q1 : * Catalog: LM22679 * Automotive: LM22679-Q1 NOTE: Qualified Version Definitions: * Catalog - TI's standard catalog product * Automotive - Q100 devices qualified for high-reliability automotive applications targeting zero defects Addendum-Page 2 PACKAGE MATERIALS INFORMATION www.ti.com 16-Sep-2020 TAPE AND REEL INFORMATION *All dimensions are nominal Device LM22679QTJ-5.0/NOPB Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant TO-263 NDR 7 1000 330.0 24.4 10.6 15.4 2.45 12.0 24.0 Q2 LM22679QTJ-ADJ/NOPB TO-263 NDR 7 1000 330.0 24.4 10.6 15.4 2.45 12.0 24.0 Q2 LM22679QTJE-5.0/NOPB TO-263 NDR 7 250 178.0 24.4 10.6 15.4 2.45 12.0 24.0 Q2 LM22679QTJE-ADJ/NOP B TO-263 NDR 7 250 178.0 24.4 10.6 15.4 2.45 12.0 24.0 Q2 LM22679TJ-5.0/NOPB TO-263 NDR 7 1000 330.0 24.4 10.6 15.4 2.45 12.0 24.0 Q2 LM22679TJ-ADJ/NOPB TO-263 NDR 7 1000 330.0 24.4 10.6 15.4 2.45 12.0 24.0 Q2 LM22679TJE-5.0/NOPB TO-263 NDR 7 250 178.0 24.4 10.6 15.4 2.45 12.0 24.0 Q2 LM22679TJE-ADJ/NOPB TO-263 NDR 7 250 178.0 24.4 10.6 15.4 2.45 12.0 24.0 Q2 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 16-Sep-2020 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM22679QTJ-5.0/NOPB TO-263 NDR 7 1000 367.0 367.0 35.0 LM22679QTJ-ADJ/NOPB TO-263 NDR 7 1000 367.0 367.0 35.0 LM22679QTJE-5.0/NOPB TO-263 NDR 7 250 210.0 185.0 35.0 LM22679QTJE-ADJ/NOPB TO-263 NDR 7 250 210.0 185.0 35.0 LM22679TJ-5.0/NOPB TO-263 NDR 7 1000 367.0 367.0 35.0 LM22679TJ-ADJ/NOPB TO-263 NDR 7 1000 367.0 367.0 35.0 LM22679TJE-5.0/NOPB TO-263 NDR 7 250 210.0 185.0 35.0 LM22679TJE-ADJ/NOPB TO-263 NDR 7 250 210.0 185.0 35.0 Pack Materials-Page 2 PACKAGE OUTLINE NDR0007A TO-263 - 2.25 mm max height SCALE 1.000 TO-263 0.25 10.1 9.6 A 0.735 0.635 C A B 7X B PIN 1 ID 1 10.41 9.91 7.62 7 6X 1.27 14.36 13.66 12.45 11.95 R0.7 MAX TYP 7X 10.76 10.26 2.1 1.9 0.508 0.381 C 0.15 7 ALL AROUND 0-0.15 STAND-OFF NOTE 5 0 -6 1.05 0.95 7.1 6.5 6.11 5.85 EXPOSED PAD (OUTLINE DOES NOT INCLUDE MOLD FLASH) 5.75 5.40 4.1 3.9 6.6 6.3 1.05 0.65 (2.66) 6.5 6.1 4219872/A 04/2019 NOTES: 1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. Features may not exist and shape may vary per different assembly sites. 4. Reference JEDEC registration TO-279B. 5. Under all conditions, leads must not be above Datum C www.ti.com EXAMPLE BOARD LAYOUT NDR0007A TO-263 - 2.25 mm max height TO-263 7X (2.41) 1 (6.35) 7X (0.91) 6X (1.27) SYMM 8 (7.62) (5.59) 7 (8.28) (0.91) PKG 0.07 MAX ALL AROUND 0.07 MIN ALL AROUND EXPOSED METAL EXPOSED METAL SOLDER MASK OPENING METAL METAL UNDER SOLDER MASK SOLDER MASK OPENING SOLDER MASK DEFINED NON SOLDER MASK DEFINED SOLDER MASK DETAILS 4219872/A 04/2019 NOTES: (continued) 6. This package is designed to be soldered to a thermal pad on the board. For more information, see Texas Instruments literature numbers SLMA002(www.ti.com/lit/slm002) and SLMA004 (www.ti.com/lit/slma004). 7. Vias are optional depending on application, refer to device data sheet. It is recommended that vias under paste be filled, plugged or tented. www.ti.com EXAMPLE STENCIL DESIGN NDR0007A TO-263 - 2.25 mm max height TO-263 7X (2.41) 7X (0.91) 1 (1.2) TYP EXPOSED METAL TYP (0.29) 6X (1.27) (1.33) TYP R(0.05) TYP (0.665) (7.62) 8 SYMM 20X (1.13) 20X (1) 7 (8.28) 0.91 PKG SOLDER PASTE EXAMPLE BASED ON 0.125 mm THICK STENCIL EXPOSED PAD 64% PRINTED SOLDER COVERAGE BY AREA SCALE:7X 4219872/A 04/2019 NOTES: (continued) 8. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate design recommendations. 9. Board assembly site may have different recommendations for stencil design. www.ti.com IMPORTANT NOTICE AND DISCLAIMER TI PROVIDES TECHNICAL AND RELIABILITY DATA (INCLUDING DATASHEETS), DESIGN RESOURCES (INCLUDING REFERENCE DESIGNS), APPLICATION OR OTHER DESIGN ADVICE, WEB TOOLS, SAFETY INFORMATION, AND OTHER RESOURCES "AS IS" AND WITH ALL FAULTS, AND DISCLAIMS ALL WARRANTIES, EXPRESS AND IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS. These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate TI products for your application, (2) designing, validating and testing your application, and (3) ensuring your application meets applicable standards, and any other safety, security, or other requirements. These resources are subject to change without notice. TI grants you permission to use these resources only for development of an application that uses the TI products described in the resource. Other reproduction and display of these resources is prohibited. No license is granted to any other TI intellectual property right or to any third party intellectual property right. TI disclaims responsibility for, and you will fully indemnify TI and its representatives against, any claims, damages, costs, losses, and liabilities arising out of your use of these resources. TI's products are provided subject to TI's Terms of Sale (www.ti.com/legal/termsofsale.html) or other applicable terms available either on ti.com or provided in conjunction with such TI products. TI's provision of these resources does not expand or otherwise alter TI's applicable warranties or warranty disclaimers for TI products. Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright (c) 2020, Texas Instruments Incorporated