LM2832 www.ti.com SNVS455A - AUGUST 2006 - REVISED APRIL 2013 LM2832 High Frequency 2.0A Load - Step-Down DC-DC Regulator Check for Samples: LM2832 FEATURES DESCRIPTION * * * * The LM2832 regulator is a monolithic, high frequency, PWM step-down DC/DC converter in a 6 Pin WSON and a 8 Pin eMSOP-PowerPAD package. It provides all the active functions to provide local DC/DC conversion with fast transient response and accurate regulation in the smallest possible PCB area. With a minimum of external components, the LM2832 is easy to use. The ability to drive 2.0A loads with an internal 150 m PMOS switch using state-of-the-art 0.5 m BiCMOS technology results in the best power density available. The world-class control circuitry allows on-times as low as 30ns, thus supporting exceptionally high frequency conversion over the entire 3V to 5.5V input operating range down to the minimum output voltage of 0.6V. Switching frequency is internally set to 550 kHz, 1.6 MHz, or 3.0 MHz, allowing the use of extremely small surface mount inductors and chip capacitors. Even though the operating frequency is high, efficiencies up to 93% are easy to achieve. External shutdown is included, featuring an ultra-low stand-by current of 30 nA. The LM2832 utilizes current-mode control and internal compensation to provide high-performance regulation over a wide range of operating conditions. Additional features include internal soft-start circuitry to reduce inrush current, pulse-by-pulse current limit, thermal shutdown, and output over-voltage protection. 1 2 * * * * * * Input Voltage Range of 3.0V to 5.5V Output Voltage Range of 0.6V to 4.5V 2.0A Output Current High Switching Frequencies - 1.6MHz (LM2832X) - 0.55MHz (LM2832Y) - 3.0MHz (LM2832Z) 150m PMOS Switch 0.6V, 2% Internal Voltage Reference Internal Soft-Start Current Mode, PWM Operation Thermal Shutdown Over Voltage Protection APPLICATIONS * * * * * Local 5V to Vcore Step-Down Converters Core Power in HDDs Set-Top Boxes USB Powered Devices DSL Modems Typical Application Circuit FB EN LM2832 R3 VIN GND L1 SW VO = 3.3V @ 2.0A VIN = 5V R1 C1 D1 C2 C3 R2 1 2 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright (c) 2006-2013, Texas Instruments Incorporated LM2832 SNVS455A - AUGUST 2006 - REVISED APRIL 2013 www.ti.com Connection Diagrams FB 1 GND 2 DAP 6 EN VIND 1 5 VINA VINA 2 8 SW 7 GND DAP SW 3 4 VIND Figure 1. 6-Pin WSON GND 3 6 FB EN 4 5 GND Figure 2. 8-Pin eMSOP-PowerPAD PIN DESCRIPTIONS 8-PIN eMSOP-PowerPAD Pin Name Function 1 VIND Power Input supply. 2 VINA Control circuitry supply voltage. Connect VINA to VIND on PC board. 3, 5, 7 GND Signal and power ground pin. Place the bottom resistor of the feedback network as close as possible to this pin. 4 EN Enable control input. Logic high enables operation. Do not allow this pin to float or be greater than VIN + 0.3V. 6 FB Feedback pin. Connect to external resistor divider to set output voltage. 8 SW Output switch. Connect to the inductor and catch diode. DAP Die Attach Pad Connect to system ground for low thermal impedance, but it cannot be used as a primary GND connection. PIN DESCRIPTIONS 6-PIN WSON Pin 2 Name 1 FB 2 GND Function Feedback pin. Connect to external resistor divider to set output voltage. Signal and power ground pin. Place the bottom resistor of the feedback network as close as possible to this pin. 3 SW 4 VIND Output switch. Connect to the inductor and catch diode. Power Input supply. 5 VINA Control circuitry supply voltage. Connect VINA to VIND on PC board. 6 EN DAP Die Attach Pad Enable control input. Logic high enables operation. Do not allow this pin to float or be greater than VINA + 0.3V. Connect to system ground for low thermal impedance, but it cannot be used as a primary GND connection. Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 LM2832 www.ti.com Absolute Maximum Ratings (1) SNVS455A - AUGUST 2006 - REVISED APRIL 2013 (2) VIN -0.5V to 7V FB Voltage -0.5V to 3V EN Voltage -0.5V to 7V SW Voltage -0.5V to 7V ESD Susceptibility 2kV Junction Temperature (3) 150C -65C to +150C Storage Temperature Soldering Information (1) (2) (3) Infrared or Convection Reflow (15 sec) 220C Absolute maximum ratings indicate limits beyond which damage to the device may occur. Operating Range indicates conditions for which the device is intended to be functional, but does not ensure specific performance limits. For ensured specifications and test conditions, see the Electrical Characteristics. If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/ Distributors for availability and specifications. Thermal shutdown will occur if the junction temperature exceeds the maximum junction temperature of the device. Operating Ratings VIN 3V to 5.5V -40C to +125C Junction Temperature Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 3 LM2832 SNVS455A - AUGUST 2006 - REVISED APRIL 2013 www.ti.com Electrical Characteristics VIN = 5V unless otherwise indicated under the Conditions column. Limits in standard type are for TJ = 25C only; limits in boldface type apply over the junction temperature (TJ) range of -40C to +125C. Minimum and Maximum limits are ensured through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TJ = 25C, and are provided for reference purposes only. Symbol VFB VFB/VIN IB UVLO Parameter Conditions Min Typ Max WSON-6 Package 0.588 0.600 0.612 Feedback Voltage eMSOP-PowerPAD-8 Package 0.584 0.600 0.616 Feedback Voltage Line Regulation VIN = 3V to 5V 0.02 Feedback Input Bias Current Undervoltage Lockout VIN Rising VIN Falling 1.85 UVLO Hysteresis FSW DMAX DMIN Switching Frequency Maximum Duty Cycle Minimum Duty Cycle RDS(ON) ICL VEN_TH (1) 4 2.90 V 2.3 1.6 1.95 LM2832-Y 0.4 0.55 0.7 LM2832-Z 2.25 3.0 3.75 LM2832-X 86 94 LM2832-Y 90 96 LM2832-Z 82 90 LM2832-X 5 LM2832-Y 2 eMSOP-PowerPAD-8 Package 155 Switch Current Limit VIN = 3.3V 2.4 Quiescent Current (switching) % % 240 3.25 Shutdown Threshold Voltage Enable Pin Current MHz 7 Switch On Resistance Switch Leakage V 1.2 150 IEN IQ nA 2.73 WSON-6 Package ISW %/V 100 LM2832-X 1.8 100 100 LM2832X VFB = 0.55 3.3 5 LM2831Y VFB = 0.55 2.8 4.5 6.5 LM2832Z VFB = 0.55 4.3 All Options VEN = 0V 30 JA Junction to Ambient 0 LFPM Air Flow (1) WSON-6 and eMSOPPowerPAD-8 Packages 80 JC Junction to Case (1) WSON-6 and eMSOPPowerPAD-8 Packages 18 TSD Thermal Shutdown Temperature 165 V nA Sink/Source Quiescent Current (shutdown) m A 0.4 Enable Threshold Voltage V 0.1 0.43 LM2832-Z Units nA mA nA C/W C/W C Applies for packages soldered directly onto a 3" x 3" PC board with 2oz. copper on 4 layers in still air. Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 LM2832 www.ti.com SNVS455A - AUGUST 2006 - REVISED APRIL 2013 Typical Performance Characteristics All curves taken at VIN = 5.0V with configuration in typical application circuit shown in Applications Information section of this datasheet. TJ = 25C, unless otherwise specified. vs Load "X, Y and Z" Vin = 3.3V, Vo = 1.8V vs Load "X" Vin = 5V, Vo = 1.8V & 3.3V Figure 3. Figure 4. vs Load - "Y" Vin = 5V, Vo = 3.3V & 1.8V vs Load "Z" Vin = 5V, Vo = 3.3V & 1.8V Figure 5. Figure 6. Load Regulation Vin = 3.3V, Vo = 1.8V (All Options) Load Regulation Vin = 5V, Vo = 1.8V (All Options) Figure 7. Figure 8. Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 5 LM2832 SNVS455A - AUGUST 2006 - REVISED APRIL 2013 www.ti.com Typical Performance Characteristics (continued) All curves taken at VIN = 5.0V with configuration in typical application circuit shown in Applications Information section of this datasheet. TJ = 25C, unless otherwise specified. Load Regulation Vin = 5V, Vo = 3.3V (All Options) Oscillator Frequency vs Temperature - "X" OSCILLATOR FREQUENCY (MHz) 1.81 1.76 1.71 1.66 1.61 1.56 1.51 1.46 1.41 1.36 -45 -40 -10 20 50 80 110 125 130 TEMPERATURE (C) Figure 9. Figure 10. Oscillator Frequency vs Temperature - "Y" Oscillator Frequency vs Temperature - "Z" 3.45 OSCILLATOR FREQUENCY (MHz) OSCILLATOR FREQUENCY (MHz) 0.60 0.58 0.56 0.54 0.52 0.50 0.48 0.46 -45 -40 -10 20 50 80 110 125 130 3.35 3.25 3.15 3.05 2.95 2.85 2.75 2.65 2.55 -45 -40 -10 20 50 80 110 125 130 TEMPERATURE (C) TEMPERATURE (C) Figure 11. Figure 12. Current Limit vs Temperature Vin = 3.3V RDSON vs Temperature (WSON-6 Package) 3800 3700 CURRENT LIMIT (mA) 3600 3500 3400 3300 3200 3100 3000 2900 2800 -45 -40 -10 20 50 80 110 125 130 TEMPERATURE (oC) Figure 13. 6 Figure 14. Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 LM2832 www.ti.com SNVS455A - AUGUST 2006 - REVISED APRIL 2013 Typical Performance Characteristics (continued) All curves taken at VIN = 5.0V with configuration in typical application circuit shown in Applications Information section of this datasheet. TJ = 25C, unless otherwise specified. RDSON vs Temperature (eMSOP-PowerPAD-8 Package) LM2832X IQ (Quiescent Current) 3.6 3.5 IQ (mA) 3.4 3.3 3.2 3.1 3.0 -45 -40 -10 20 50 80 110 125 130 TEMPERATURE (C) Figure 15. Figure 16. LM2832Y IQ (Quiescent Current) LM2832Z IQ (Quiescent Current) 2.65 4.6 2.6 4.5 2.55 4.4 2.45 IQ (mA) IQ (mA) 2.5 2.4 2.35 4.3 4.2 2.3 2.25 4.1 2.2 2.15 -45 -40 -10 20 50 80 4.0 -45 110 125 130 TEMPERATURE (C) -40 -10 20 50 80 110 125 130 TEMPERATURE (C) Figure 17. Figure 18. Line Regulation Vo = 1.8V, Io = 500mA VFB vs Temperature FEEBACK VOLTAGE (V) 0.610 0.605 0.600 0.595 0.590 -45 -40 -10 20 50 80 110 125 130 TEMPERATURE (C) Figure 19. Figure 20. Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 7 LM2832 SNVS455A - AUGUST 2006 - REVISED APRIL 2013 www.ti.com Typical Performance Characteristics (continued) All curves taken at VIN = 5.0V with configuration in typical application circuit shown in Applications Information section of this datasheet. TJ = 25C, unless otherwise specified. Gain vs Frequency (Vin = 5V, Vo = 1.2V @ 1A) Phase Plot vs Frequency (Vin = 5V, Vo = 1.2V @ 1A) Figure 21. Figure 22. Simplified Block Diagram EN VIN + ENABLE and UVLO ThermalSHDN I SENSE - + - I LIMIT - 1 .15 x VREF + OVPSHDN Ramp Artificial Control Logic cv FB S R R Q 1.6 MHz + I SENSE PFET - + DRIVER Internal - Comp SW VREF = 0.6V SOFT - START Internal - LDO GND Figure 23. 8 Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 LM2832 www.ti.com SNVS455A - AUGUST 2006 - REVISED APRIL 2013 APPLICATIONS INFORMATION THEORY OF OPERATION The LM2832 is a constant frequency PWM buck regulator IC that delivers a 2.0A load current. The regulator has a preset switching frequency of 1.6MHz or 3.0MHz. This high frequency allows the LM2832 to operate with small surface mount capacitors and inductors, resulting in a DC/DC converter that requires a minimum amount of board space. The LM2832 is internally compensated, so it is simple to use and requires few external components. The LM2832 uses current-mode control to regulate the output voltage. The following operating description of the LM2832 will refer to the Simplified Block Diagram (Figure 23) and to the waveforms in Figure 24. The LM2832 supplies a regulated output voltage by switching the internal PMOS control switch at constant frequency and variable duty cycle. A switching cycle begins at the falling edge of the reset pulse generated by the internal oscillator. When this pulse goes low, the output control logic turns on the internal PMOS control switch. During this on-time, the SW pin voltage (VSW) swings up to approximately VIN, and the inductor current (IL) increases with a linear slope. IL is measured by the current sense amplifier, which generates an output proportional to the switch current. The sense signal is summed with the regulator's corrective ramp and compared to the error amplifier's output, which is proportional to the difference between the feedback voltage and VREF. When the PWM comparator output goes high, the output switch turns off until the next switching cycle begins. During the switch off-time, inductor current discharges through the Schottky catch diode, which forces the SW pin to swing below ground by the forward voltage (VD) of the Schottky catch diode. The regulator loop adjusts the duty cycle (D) to maintain a constant output voltage. VSW D = TON/TSW VIN SW Voltage TOFF TON 0 VD t TSW IL IPK Inductor Current t 0 Figure 24. Typical Waveforms SOFT-START This function forces VOUT to increase at a controlled rate during start up. During soft-start, the error amplifier's reference voltage ramps from 0V to its nominal value of 0.6V in approximately 600 s. This forces the regulator output to ramp up in a controlled fashion, which helps reduce inrush current. OUTPUT OVERVOLTAGE PROTECTION The over-voltage comparator compares the FB pin voltage to a voltage that is 15% higher than the internal reference VREF. Once the FB pin voltage goes 15% above the internal reference, the internal PMOS control switch is turned off, which allows the output voltage to decrease toward regulation. UNDERVOLTAGE LOCKOUT Under-voltage lockout (UVLO) prevents the LM2832 from operating until the input voltage exceeds 2.73V (typ). The UVLO threshold has approximately 430 mV of hysteresis, so the part will operate until VIN drops below 2.3V (typ). Hysteresis prevents the part from turning off during power up if VIN is non-monotonic. Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 9 LM2832 SNVS455A - AUGUST 2006 - REVISED APRIL 2013 www.ti.com CURRENT LIMIT The LM2832 uses cycle-by-cycle current limiting to protect the output switch. During each switching cycle, a current limit comparator detects if the output switch current exceeds 3.25A (typ), and turns off the switch until the next switching cycle begins. THERMAL SHUTDOWN Thermal shutdown limits total power dissipation by turning off the output switch when the IC junction temperature exceeds 165C. After thermal shutdown occurs, the output switch doesn't turn on until the junction temperature drops to approximately 150C. Design Guide INDUCTOR SELECTION The Duty Cycle (D) can be approximated quickly using the ratio of output voltage (VO) to input voltage (VIN): D= VOUT VIN (1) The catch diode (D1) forward voltage drop and the voltage drop across the internal PMOS must be included to calculate a more accurate duty cycle. Calculate D by using the following formula: VOUT + VD D= VIN + VD - VSW (2) VSW can be approximated by: VSW = IOUT x RDSON (3) The diode forward drop (VD) can range from 0.3V to 0.7V depending on the quality of the diode. The lower the VD, the higher the operating efficiency of the converter. The inductor value determines the output ripple current. Lower inductor values decrease the size of the inductor, but increase the output ripple current. An increase in the inductor value will decrease the output ripple current. One must ensure that the minimum current limit (2.4A) is not exceeded, so the peak current in the inductor must be calculated. The peak current (ILPK) in the inductor is calculated by: ILPK = IOUT + iL (4) 'i L I OUT VIN - VOUT VOUT L L DTS TS t Figure 25. Inductor Current VIN - VOUT L = 2'iL DTS (5) In general, iL = 0.1 x (IOUT) 0.2 x (IOUT) (6) If iL = 20% of 2A, the peak current in the inductor will be 2.4A. The minimum ensured current limit over all operating conditions is 2.4A. One can either reduce iL, or make the engineering judgment that zero margin will be safe enough. The typical current limit is 3.25A. 10 Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 LM2832 www.ti.com SNVS455A - AUGUST 2006 - REVISED APRIL 2013 The LM2832 operates at frequencies allowing the use of ceramic output capacitors without compromising transient response. Ceramic capacitors allow higher inductor ripple without significantly increasing output ripple. See the OUTPUT CAPACITOR for more details on calculating output voltage ripple. Now that the ripple current is determined, the inductance is calculated by: DTS x (VIN - VOUT) L= 2'iL where TS = 1 fS (8) (8) When selecting an inductor, make sure that it is capable of supporting the peak output current without saturating. Inductor saturation will result in a sudden reduction in inductance and prevent the regulator from operating correctly. Because of the speed of the internal current limit, the peak current of the inductor need only be specified for the required maximum output current. For example, if the designed maximum output current is 1.0A and the peak current is 1.25A, then the inductor should be specified with a saturation current limit of > 1.25A. There is no need to specify the saturation or peak current of the inductor at the 3.25A typical switch current limit. The difference in inductor size is a factor of 5. Because of the operating frequency of the LM2832, ferrite based inductors are preferred to minimize core losses. This presents little restriction since the variety of ferrite-based inductors is huge. Lastly, inductors with lower series resistance (RDCR) will provide better operating efficiency. For recommended inductors see Example Circuits. INPUT CAPACITOR An input capacitor is necessary to ensure that VIN does not drop excessively during switching transients. The primary specifications of the input capacitor are capacitance, voltage, RMS current rating, and ESL (Equivalent Series Inductance). The recommended input capacitance is 22 F.The input voltage rating is specifically stated by the capacitor manufacturer. Make sure to check any recommended deratings and also verify if there is any significant change in capacitance at the operating input voltage and the operating temperature. The input capacitor maximum RMS input current rating (IRMS-IN) must be greater than: IRMS_IN D IOUT2 (1-D) + 'i2 3 (9) Neglecting inductor ripple simplifies the above equation to: IRMS_IN = IOUT x D(1 - D) (10) It can be shown from the above equation that maximum RMS capacitor current occurs when D = 0.5. Always calculate the RMS at the point where the duty cycle D is closest to 0.5. The ESL of an input capacitor is usually determined by the effective cross sectional area of the current path. A large leaded capacitor will have high ESL and a 0805 ceramic chip capacitor will have very low ESL. At the operating frequencies of the LM2832, leaded capacitors may have an ESL so large that the resulting impedance (2fL) will be higher than that required to provide stable operation. As a result, surface mount capacitors are strongly recommended. Sanyo POSCAP, Tantalum or Niobium, Panasonic SP, and multilayer ceramic capacitors (MLCC) are all good choices for both input and output capacitors and have very low ESL. For MLCCs it is recommended to use X7R or X5R type capacitors due to their tolerance and temperature characteristics. Consult capacitor manufacturer datasheets to see how rated capacitance varies over operating conditions. OUTPUT CAPACITOR The output capacitor is selected based upon the desired output ripple and transient response. The initial current of a load transient is provided mainly by the output capacitor. The output ripple of the converter is: 1 'VOUT = 'IL RESR + 8 x FSW x COUT (11) Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 11 LM2832 SNVS455A - AUGUST 2006 - REVISED APRIL 2013 www.ti.com When using MLCCs, the ESR is typically so low that the capacitive ripple may dominate. When this occurs, the output ripple will be approximately sinusoidal and 90 phase shifted from the switching action. Given the availability and quality of MLCCs and the expected output voltage of designs using the LM2832, there is really no need to review any other capacitor technologies. Another benefit of ceramic capacitors is their ability to bypass high frequency noise. A certain amount of switching edge noise will couple through parasitic capacitances in the inductor to the output. A ceramic capacitor will bypass this noise while a tantalum will not. Since the output capacitor is one of the two external components that control the stability of the regulator control loop, most applications will require a minimum of 22 F of output capacitance. Capacitance often, but not always, can be increased significantly with little detriment to the regulator stability. Like the input capacitor, recommended multilayer ceramic capacitors are X7R or X5R types. CATCH DIODE The catch diode (D1) conducts during the switch off-time. A Schottky diode is recommended for its fast switching times and low forward voltage drop. The catch diode should be chosen so that its current rating is greater than: ID1 = IOUT x (1-D) (12) The reverse breakdown rating of the diode must be at least the maximum input voltage plus appropriate margin. To improve efficiency, choose a Schottky diode with a low forward voltage drop. OUTPUT VOLTAGE The output voltage is set using the following equation where R2 is connected between the FB pin and GND, and R1 is connected between VO and the FB pin. A good value for R2 is 10k. When designing a unity gain converter (Vo = 0.6V), R1 should be between 0 and 100, and R2 should be equal or greater than 10k. VOUT - 1 x R2 R1 = VREF (13) VREF = 0.60V (14) PCB LAYOUT CONSIDERATIONS When planning layout there are a few things to consider when trying to achieve a clean, regulated output. The most important consideration is the close coupling of the GND connections of the input capacitor and the catch diode D1. These ground ends should be close to one another and be connected to the GND plane with at least two through-holes. Place these components as close to the IC as possible. Next in importance is the location of the GND connection of the output capacitor, which should be near the GND connections of CIN and D1. There should be a continuous ground plane on the bottom layer of a two-layer board except under the switching node island. The FB pin is a high impedance node and care should be taken to make the FB trace short to avoid noise pickup and inaccurate regulation. The feedback resistors should be placed as close as possible to the IC, with the GND of R1 placed as close as possible to the GND of the IC. The VOUT trace to R2 should be routed away from the inductor and any other traces that are switching. High AC currents flow through the VIN, SW and VOUT traces, so they should be as short and wide as possible. However, making the traces wide increases radiated noise, so the designer must make this trade-off. Radiated noise can be decreased by choosing a shielded inductor. The remaining components should also be placed as close as possible to the IC. Please see Application Note AN-1229 SNVA054 for further considerations and the LM2832 demo board as an example of a four-layer layout. Calculating Efficiency, and Junction Temperature The complete LM2832 DC/DC converter efficiency can be calculated in the following manner. K= POUT PIN (15) Or K= POUT POUT + PLOSS (16) Calculations for determining the most significant power losses are shown below. Other losses totaling less than 2% are not discussed. 12 Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 LM2832 www.ti.com SNVS455A - AUGUST 2006 - REVISED APRIL 2013 Power loss (PLOSS) is the sum of two basic types of losses in the converter: switching and conduction. Conduction losses usually dominate at higher output loads, whereas switching losses remain relatively fixed and dominate at lower output loads. The first step in determining the losses is to calculate the duty cycle (D): D= VOUT + VD VIN + VD - VSW (17) VSW is the voltage drop across the internal PFET when it is on, and is equal to: VSW = IOUT x RDSON (18) VD is the forward voltage drop across the Schottky catch diode. It can be obtained from the diode manufactures Electrical Characteristics section. If the voltage drop across the inductor (VDCR) is accounted for, the equation becomes: D= VOUT + VD + VDCR VIN + VD + VDCR - VSW (19) The conduction losses in the free-wheeling Schottky diode are calculated as follows: PDIODE = VD x IOUT x (1-D) (20) Often this is the single most significant power loss in the circuit. Care should be taken to choose a Schottky diode that has a low forward voltage drop. Another significant external power loss is the conduction loss in the output inductor. The equation can be simplified to: PIND = IOUT2 x RDCR (21) The LM2832 conduction loss is mainly associated with the internal PFET: PCOND = (IOUT2 x D) 1 + 'iL 1 x 3 IOUT 2 RDSON (22) If the inductor ripple current is fairly small, the conduction losses can be simplified to: PCOND = IOUT2 x RDSON x D (23) Switching losses are also associated with the internal PFET. They occur during the switch on and off transition periods, where voltages and currents overlap resulting in power loss. The simplest means to determine this loss is to empirically measuring the rise and fall times (10% to 90%) of the switch at the switch node. Switching Power Loss is calculated as follows: PSWR = 1/2(VIN x IOUT x FSW x TRISE) PSWF = 1/2(VIN x IOUT x FSW x TFALL) PSW = PSWR + PSWF (24) (25) (26) Another loss is the power required for operation of the internal circuitry: PQ = IQ x VIN (27) IQ is the quiescent operating current, and is typically around 2.5mA for the 0.55MHz frequency option. Typical Application power losses are: Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 13 LM2832 SNVS455A - AUGUST 2006 - REVISED APRIL 2013 www.ti.com Table 1. Power Loss Tabulation VIN 5.0V VOUT 3.3V IOUT 1.75A POUT 5.78W PDIODE 262mW VD 0.45V FSW 550kHz IQ 2.5mA PQ 12.5mW 10mW TRISE 4nS PSWR TFALL 4nS PSWF 10mW RDS(ON) 150m PCOND 306mW INDDCR 50m PIND 153mW D 0.667 PLOSS 753mW 88% PINTERNAL 339mW PCOND + PSW + PDIODE + PIND + PQ = PLOSS PCOND + PSWF + PSWR + PQ = PINTERNAL PINTERNAL = 339mW (28) (29) (30) Thermal Definitions TJ Chip junction temperature TA Ambient temperature RJC Thermal resistance from chip junction to device case RJA Thermal resistance from chip junction to ambient air Heat in the LM2832 due to internal power dissipation is removed through conduction and/or convection. Conduction Heat transfer occurs through cross sectional areas of material. Depending on the material, the transfer of heat can be considered to have poor to good thermal conductivity properties (insulator vs. conductor). Heat Transfer goes as: Silicon package lead frame PCB Convection Heat transfer is by means of airflow. This could be from a fan or natural convection. Natural convection occurs when air currents rise from the hot device to cooler air. Thermal impedance is defined as: RT = 'T Power (31) Thermal impedance from the silicon junction to the ambient air is defined as: RTJA = TJ - TA Power (32) The PCB size, weight of copper used to route traces and ground plane, and number of layers within the PCB can greatly effect RJA. The type and number of thermal vias can also make a large difference in the thermal impedance. Thermal vias are necessary in most applications. They conduct heat from the surface of the PCB to the ground plane. Four to six thermal vias should be placed under the exposed pad to the ground plane if the WSON package is used. Thermal impedance also depends on the thermal properties of the application operating conditions (Vin, Vo, Io etc), and the surrounding circuitry. 14 Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 LM2832 www.ti.com SNVS455A - AUGUST 2006 - REVISED APRIL 2013 Silicon Junction Temperature Determination Method 1: To accurately measure the silicon temperature for a given application, two methods can be used. The first method requires the user to know the thermal impedance of the silicon junction to top case temperature. Some clarification needs to be made before we go any further. RJC is the thermal impedance from all six sides of an IC package to silicon junction. RJC is the thermal impedance from top case to the silicon junction. In this data sheet we will use RJC so that it allows the user to measure top case temperature with a small thermocouple attached to the top case. RJC is approximately 30C/Watt for the 6-pin WSON package with the exposed pad. Knowing the internal dissipation from the efficiency calculation given previously, and the case temperature, which can be empirically measured on the bench we have: TJ - TC R)JC = Power (33) Therefore: Tj = (RJC x PLOSS) + TC (34) From the previous example: Tj = (RJC x PINTERNAL) + TC Tj = 30C/W x 0.339W + TC (35) (36) The second method can give a very accurate silicon junction temperature. The first step is to determine RJA of the application. The LM2832 has over-temperature protection circuitry. When the silicon temperature reaches 165C, the device stops switching. The protection circuitry has a hysteresis of about 15C. Once the silicon temperature has decreased to approximately 150C, the device will start to switch again. Knowing this, the RJA for any application can be characterized during the early stages of the design one may calculate the RJA by placing the PCB circuit into a thermal chamber. Raise the ambient temperature in the given working application until the circuit enters thermal shutdown. If the SW-pin is monitored, it will be obvious when the internal PFET stops switching, indicating a junction temperature of 165C. Knowing the internal power dissipation from the above methods, the junction temperature, and the ambient temperature RJA can be determined. RTJA = 165 - Ta PINTERNAL (37) Once this is determined, the maximum ambient temperature allowed for a desired junction temperature can be found. An example of calculating RJA for an application using the Texas Instruments LM2832 WSON demonstration board is shown below. The four layer PCB is constructed using FR4 with 1/2 oz copper traces. The copper ground plane is on the bottom layer. The ground plane is accessed by two vias. The board measures 3.0cm x 3.0cm. It was placed in an oven with no forced airflow. The ambient temperature was raised to 126C, and at that temperature, the device went into thermal shutdown. From the previous example: PINTERNAL = 339mW RTJA = (38) 165oC - 126oC = 115o C/W 339 mW (39) If the junction temperature was to be kept below 125C, then the ambient temperature could not go above 86C. Tj - (RJA x PLOSS) = TA (40) Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 15 LM2832 SNVS455A - AUGUST 2006 - REVISED APRIL 2013 www.ti.com 125C - (115C/W x 339mW) = 86C 16 (41) Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 LM2832 www.ti.com SNVS455A - AUGUST 2006 - REVISED APRIL 2013 WSON Package Figure 26. Internal WSON Connection For certain high power applications, the PCB land may be modified to a "dog bone" shape (see Figure 27). By increasing the size of ground plane, and adding thermal vias, the RJA for the application can be reduced. FB GND 6 EN 1 2 GND PLANE SW 3 5 VINA 4 VIND Figure 27. 6-Lead WSON PCB Dog Bone Layout Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 17 LM2832 SNVS455A - AUGUST 2006 - REVISED APRIL 2013 www.ti.com LM2832X Design Example 1 FB EN LM2832 R3 GND L1 VIN VO = 1.2V @ 2.0A SW VIN = 5V R1 C1 D1 C2 R2 Figure 28. LM2832X (1.6MHz): Vin = 5V, Vo = 1.2V @ 2.0A Table 2. Bill of Materials 18 Part ID Part Value Manufacturer U1 2.0A Buck Regulator TI Part Number LM2832X C1, Input Cap 22F, 6.3V, X5R TDK C3216X5ROJ226M C3216X5ROJ226M C2, Output Cap 2x22F, 6.3V, X5R TDK D1, Catch Diode 0.4Vf Schottky 2A, 20VR Diodes Inc. B220/A L1 2.2H, 3.5A Coilcraft DS3316P-222 R2 15.0k, 1% Vishay CRCW08051502F R1 15.0k, 1% Vishay CRCW08051502F R3 100k, 1% Vishay CRCW08051003F Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 LM2832 www.ti.com SNVS455A - AUGUST 2006 - REVISED APRIL 2013 LM2832X Design Example 2 FB EN LM2832 R3 GND L1 VIN VO = 0.6V @ 2.0A SW VIN = 5V R1 C1 D1 C2 R2 Figure 29. LM2832X (1.6MHz): Vin = 5V, Vo = 0.6V @ 2.0A Table 3. Bill of Materials Part ID Part Value Manufacturer U1 2.0A Buck Regulator TI Part Number LM2832X C1, Input Cap 22F, 6.3V, X5R TDK C3216X5ROJ226M C3216X5ROJ226M C2, Output Cap 2x22F, 6.3V, X5R TDK D1, Catch Diode 0.4Vf Schottky 2A, 20VR Diodes Inc. B220/A L1 3.3H, 3.3A Coilcraft DS3316P-332 R2 10.0k, 1% Vishay CRCW08051000F R1 0 R3 100k, 1% Vishay CRCW08051003F Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 19 LM2832 SNVS455A - AUGUST 2006 - REVISED APRIL 2013 www.ti.com LM2832X Design Example 3 FB EN LM2832 R3 GND L1 VIN VO = 3.3V @ 2.0A SW VIN = 5V R1 C1 D1 C2 R2 Figure 30. LM2832X (1.6MHz): Vin = 5V, Vo = 3.3V @ 2.0A Table 4. Bill of Materials 20 Part ID Part Value Manufacturer U1 2.0A Buck Regulator TI Part Number LM2832X C1, Input Cap 22F, 6.3V, X5R TDK C3216X5ROJ226M C3216X5ROJ226M C2, Output Cap 2x22F, 6.3V, X5R TDK D1, Catch Diode 0.4Vf Schottky 2A, 20VR Diodes Inc. B220/A L1 2.2H, 2.8A Coilcraft ME3220-222 R2 10.0k, 1% Vishay CRCW08051002F R1 45.3k, 1% Vishay CRCW08054532F R3 100k, 1% Vishay CRCW08051003F Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 LM2832 www.ti.com SNVS455A - AUGUST 2006 - REVISED APRIL 2013 LM2832Y Design Example 4 FB EN LM2832 R3 GND L1 VIN VO = 3.3V @ 2.0A SW VIN = 5V R1 C1 D1 C2 R2 Figure 31. LM2832Y (550kHz): Vin = 5V, Vout = 3.3V @ 2.0A Table 5. Bill of Materials Part ID Part Value Manufacturer U1 1.5A Buck Regulator TI Part Number LM2832Y C1, Input Cap 22F, 6.3V, X5R TDK C3216X5ROJ226M C3216X5ROJ226M C2, Output Cap 2x22F, 6.3V, X5R TDK D1, Catch Diode 0.3Vf Schottky 1.5A, 30VR TOSHIBA CRS08 L1 4.7H 2.1A TDK SLF7045T-4R7M2R0-PF R1 10.0k, 1% Vishay CRCW08051002F R2 10.0k, 1% Vishay CRCW08051002F Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 21 LM2832 SNVS455A - AUGUST 2006 - REVISED APRIL 2013 www.ti.com LM2832Y Design Example 5 FB EN LM2832 R3 GND L1 VIN VO = 1.2V @ 2.0A SW VIN = 5V R1 C1 D1 C2 R2 Figure 32. LM2832Y (550kHz): Vin = 5V, Vout = 1.2V @ 2.0A Table 6. Bill of Materials 22 Part ID Part Value Manufacturer U1 1.5A Buck Regulator TI Part Number LM2832Y C1, Input Cap 22F, 6.3V, X5R TDK C3216X5ROJ226M C3216X5ROJ226M C2, Output Cap 2x22F, 6.3V, X5R TDK D1, Catch Diode 0.3Vf Schottky 1.5A, 30VR TOSHIBA CRS08 L1 6.8H 1.8A TDK SLF7045T-6R8M1R7 R1 10.0k, 1% Vishay CRCW08051002F R2 10.0k, 1% Vishay CRCW08051002F Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 LM2832 www.ti.com SNVS455A - AUGUST 2006 - REVISED APRIL 2013 LM2832Z Design Example 6 FB EN LM2832 R3 GND L1 VIN VO = 3.3V @ 2.0A SW VIN = 5V R1 C1 D1 C2 R2 Figure 33. LM2832Z (3MHz): Vin = 5V, Vo = 3.3V @ 2.0A Table 7. Bill of Materials Part ID Part Value Manufacturer U1 2.0A Buck Regulator TI Part Number LM2832Z C1, Input Cap 22F, 6.3V, X5R TDK C3216X5ROJ226M C3216X5ROJ226M C2, Output Cap 2x22F, 6.3V, X5R TDK D1, Catch Diode 0.4Vf Schottky 2A, 20VR Diodes Inc. B220/A L1 3.3H, 3.3A Coilcraft DS3316P-332 R2 10.0k, 1% Vishay CRCW08051002F R1 45.3k, 1% Vishay CRCW08054532F R3 100k, 1% Vishay CRCW08051003F Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 23 LM2832 SNVS455A - AUGUST 2006 - REVISED APRIL 2013 www.ti.com LM2832Z Design Example 7 FB EN LM2832 R3 GND L1 VIN VO = 1.2V @ 2.0A SW VIN = 5V R1 C1 D1 C2 R2 Figure 34. LM2832Z (3MHz): Vin = 5V, Vo = 1.2V @ 2.0A Table 8. Bill of Materials 24 Part ID Part Value Manufacturer U1 2.0A Buck Regulator TI Part Number LM2832Z C1, Input Cap 22F, 6.3V, X5R TDK C3216X5ROJ226M C3216X5ROJ226M C2, Output Cap 2x22F, 6.3V, X5R TDK D1, Catch Diode 0.4Vf Schottky 2A, 20VR Diodes Inc. B220/A L1 4.7H, 2.7A Coilcraft DS3316P-472 R2 10.0k, 1% Vishay CRCW08051002F R1 10.0k, 1% Vishay CRCW08051002F R3 100k, 1% Vishay CRCW08051003F Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 LM2832 www.ti.com SNVS455A - AUGUST 2006 - REVISED APRIL 2013 LM2832X Dual Converters with Delayed Enabled Design Example 8 VIN U1 C1 R3 VIND VINA L1 VO = 3.3V @ 2.0A SW EN R1 D1 LM2832 C2 R2 GND FB U3 4 R6 3 LP3470M5X-3.08 LP3470 RESET 5 2 1 VIN C7 U2 C3 VIND VINA L2 VO = 1.2V @ 2.0A SW R4 LM2832 D2 C4 R5 EN GND FB Figure 35. LM2832X (1.6MHz): Vin = 5V, Vo = 1.2V @ 2.0A & 3.3V @2.0A Table 9. Bill of Materials Part ID Part Value Manufacturer Part Number U1, U2 2.0A Buck Regulator TI LM2832X U3 Power on Reset TI LP3470M5X-3.08 C1, C3 Input Cap 22F, 6.3V, X5R TDK C3216X5ROJ226M C2, C4 Output Cap 2x22F, 6.3V, X5R TDK C3216X5ROJ226M C7 Trr delay capacitor TDK D1, D2 Catch Diode 0.4Vf Schottky 2A, 20VR Diodes Inc. B220/A L1, L2 3.3H, 2.7A Coilcraft ME3220-102 R2, R4, R5 10.0k, 1% Vishay CRCW08051002F R1, R6 45.3k, 1% Vishay CRCW08054532F R3 100k, 1% Vishay CRCW08051003F Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 25 LM2832 SNVS455A - AUGUST 2006 - REVISED APRIL 2013 www.ti.com LM2832X Buck Converter & Voltage Double Circuit with LDO Follower Design Example 9 VO = 5.0V @ 150mA L2 U2 LDO D2 C6 U1 C3 LM2832 VIN = 5V VIND SW VINA GND C1 EN C5 C4 L1 R1 FB VO = 3.3V @ 2.0A C2 D1 R2 Figure 36. LM2832X (1.6MHz): Vin = 5V, Vo = 3.3V @ 2.0A & LP2986-5.0 @ 150mA Table 10. Bill of Materials 26 Part ID Part Value Manufacturer Part Number U1 2.0A Buck Regulator TI LM2832X U2 200mA LDO TI LP2986-5.0 C1, Input Cap 22F, 6.3V, X5R TDK C3216X5ROJ226M C2, Output Cap 2x22F, 6.3V, X5R TDK C3216X5ROJ226M C1608X5R0J225M C3 - C6 2.2F, 6.3V, X5R TDK D1, Catch Diode 0.4Vf Schottky 2A, 20VR Diodes Inc. B220/A D2 0.4Vf Schottky 20VR, 500mA ON Semi MBR0520 L2 10H, 800mA CoilCraft ME3220-103 L1 2.2H, 3.5A CoilCraft DS3316P-222 R2 45.3k, 1% Vishay CRCW08054532F R1 10.0k, 1% Vishay CRCW08051002F Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 LM2832 www.ti.com SNVS455A - AUGUST 2006 - REVISED APRIL 2013 REVISION HISTORY Changes from Original (April 2013) to Revision A * Page Changed layout of National Data Sheet to TI format .......................................................................................................... 26 Submit Documentation Feedback Copyright (c) 2006-2013, Texas Instruments Incorporated Product Folder Links: LM2832 27 PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (C) Device Marking (4/5) LM2832XMY NRND HVSSOP DGN 8 1000 TBD Call TI Call TI -40 to 125 SLBB LM2832XMY/NOPB ACTIVE HVSSOP DGN 8 1000 Green (RoHS & no Sb/Br) SN Level-1-260C-UNLIM -40 to 125 SLBB LM2832XSD/NOPB ACTIVE WSON NGG 6 1000 Green (RoHS & no Sb/Br) SN Level-3-260C-168 HR -40 to 125 L196B LM2832YMY/NOPB ACTIVE HVSSOP DGN 8 1000 Green (RoHS & no Sb/Br) SN Level-1-260C-UNLIM -40 to 125 SLCB LM2832YSD/NOPB ACTIVE WSON NGG 6 1000 Green (RoHS & no Sb/Br) SN Level-3-260C-168 HR -40 to 125 L197B LM2832ZMY/NOPB ACTIVE HVSSOP DGN 8 1000 Green (RoHS & no Sb/Br) SN Level-1-260C-UNLIM -40 to 125 SLDB LM2832ZSD/NOPB ACTIVE WSON NGG 6 1000 Green (RoHS & no Sb/Br) SN Level-3-260C-168 HR -40 to 125 L198B (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. (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. Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com 6-Feb-2020 (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish 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. Addendum-Page 2 PACKAGE MATERIALS INFORMATION www.ti.com 29-Sep-2019 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ LM2832XMY HVSSOP LM2832XMY/NOPB LM2832XSD/NOPB Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant DGN 8 1000 178.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 HVSSOP DGN 8 1000 178.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 WSON NGG 6 1000 178.0 12.4 3.3 3.3 1.0 8.0 12.0 Q1 LM2832YMY/NOPB HVSSOP DGN 8 1000 178.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 LM2832YSD/NOPB WSON NGG 6 1000 178.0 12.4 3.3 3.3 1.0 8.0 12.0 Q1 LM2832ZMY/NOPB HVSSOP DGN 8 1000 178.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 LM2832ZSD/NOPB WSON NGG 6 1000 178.0 12.4 3.3 3.3 1.0 8.0 12.0 Q1 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 29-Sep-2019 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM2832XMY HVSSOP DGN 8 1000 210.0 185.0 35.0 LM2832XMY/NOPB HVSSOP DGN 8 1000 210.0 185.0 35.0 LM2832XSD/NOPB WSON NGG 6 1000 210.0 185.0 35.0 LM2832YMY/NOPB HVSSOP DGN 8 1000 210.0 185.0 35.0 LM2832YSD/NOPB WSON NGG 6 1000 210.0 185.0 35.0 LM2832ZMY/NOPB HVSSOP DGN 8 1000 210.0 185.0 35.0 LM2832ZSD/NOPB WSON NGG 6 1000 210.0 185.0 35.0 Pack Materials-Page 2 PACKAGE OUTLINE TM DGN0008A PowerPAD VSSOP - 1.1 mm max height SCALE 4.000 SMALL OUTLINE PACKAGE C 5.05 TYP 4.75 A 0.1 C SEATING PLANE PIN 1 INDEX AREA 6X 0.65 8 1 2X 3.1 2.9 NOTE 3 1.95 4 5 8X B 3.1 2.9 NOTE 4 0.38 0.25 0.13 C A B 0.23 0.13 SEE DETAIL A EXPOSED THERMAL PAD 4 5 0.25 GAGE PLANE 2.0 1.7 9 1.1 MAX 8 1 0 -8 0.15 0.05 0.7 0.4 DETAIL A A 20 1.88 1.58 TYPICAL 4218836/A 11/2019 PowerPAD is a trademark of Texas Instruments. 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. This dimension does not include mold flash, protrusions, or gate burrs. Mold flash, protrusions, or gate burrs shall not exceed 0.15 mm per side. 4. This dimension does not include interlead flash. Interlead flash shall not exceed 0.25 mm per side. 5. Reference JEDEC registration MO-187. www.ti.com EXAMPLE BOARD LAYOUT TM DGN0008A PowerPAD VSSOP - 1.1 mm max height SMALL OUTLINE PACKAGE (2) NOTE 9 METAL COVERED BY SOLDER MASK (1.88) SOLDER MASK DEFINED PAD SYMM 8X (1.4) (R0.05) TYP 8 8X (0.45) 1 (3) NOTE 9 SYMM 9 (2) (1.22) 6X (0.65) 5 4 ( 0.2) TYP VIA (0.55) SEE DETAILS (4.4) LAND PATTERN EXAMPLE EXPOSED METAL SHOWN SCALE: 15X SOLDER MASK OPENING METAL UNDER SOLDER MASK METAL SOLDER MASK OPENING EXPOSED METAL EXPOSED METAL 0.05 MAX ALL AROUND NON-SOLDER MASK DEFINED (PREFERRED) 0.05 MIN ALL AROUND SOLDER MASK DEFINED SOLDER MASK DETAILS 15.000 4218836/A 11/2019 NOTES: (continued) 6. Publication IPC-7351 may have alternate designs. 7. Solder mask tolerances between and around signal pads can vary based on board fabrication site. 8. Vias are optional depending on application, refer to device data sheet. If any vias are implemented, refer to their locations shown on this view. It is recommended that vias under paste be filled, plugged or tented. 9. Size of metal pad may vary due to creepage requirement. www.ti.com EXAMPLE STENCIL DESIGN TM DGN0008A PowerPAD VSSOP - 1.1 mm max height SMALL OUTLINE PACKAGE (1.88) BASED ON 0.125 THICK STENCIL SYMM (R0.05) TYP 8X (1.4) 8X (0.45) 8 1 SYMM (2) BASED ON 0.125 THICK STENCIL 6X (0.65) 5 4 METAL COVERED BY SOLDER MASK (4.4) SEE TABLE FOR DIFFERENT OPENINGS FOR OTHER STENCIL THICKNESSES SOLDER PASTE EXAMPLE EXPOSED PAD 9: 100% PRINTED SOLDER COVERAGE BY AREA SCALE: 15X STENCIL THICKNESS SOLDER STENCIL OPENING 0.1 0.125 0.15 0.175 2.10 X 2.24 1.88 X 2.00 (SHOWN) 1.72 X 1.83 1.59 X 1.69 4218836/A 11/2019 NOTES: (continued) 10. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate design recommendations. 11. Board assembly site may have different recommendations for stencil design. www.ti.com MECHANICAL DATA NGG0006A SDE06A (Rev A) 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. 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