National Semiconductor is now part of Texas Instruments. Search http://www.ti.com/ for the latest technical information and details on our current products and services. LM6142QML 17 MHz Rail-to-Rail Input-Output Operational Amplifiers General Description Features Using patented new circuit topologies, the LM6142 provides new levels of performance in applications where low voltage supplies or power limitations previously made compromise necessary. Operating on supplies of 2.7V to over 24V, the LM6142 is an excellent choice for battery operated systems, portable instrumentation and others. At VS = 5V. Typ unless noted. n Rail-to-rail input CMVR -0.25V to 5.25V n Rail-to-rail output swing 0.005V to 4.995V n Wide gain-bandwidth: 17MHz (typ) n Slew rate: Small signal, 5V/s Large signal, 30V/s n Low supply current 650A/Amplifier n Wide supply range 2.8V to 24V n CMRR 107dB n Gain 108dB with RL = 10k n PSRR 87dB The greater than rail-to-rail input voltage range eliminates concern over exceeding the common-mode voltage range. The rail-to-rail output swing provides the maximum possible dynamic range at the output. This is particularly important when operating on low supply voltages. High gain-bandwidth with 650A/Amplifier supply current opens new battery powered applications where previous higher power consumption reduced battery life to unacceptable levels. The ability to drive large capacitive loads without oscillating functionally removes this common problem. Applications n n n n n Battery operated instrumentation Portable sonar Barcode scanners Wireless communications Rail-to-rail in-out instrumentation amps Ordering Information NS Part Number JAN Part Number NS Package Number Package Description LM6142AMJ-QML 5962-9550301QPA J08A 8LD CERDIP Connection Diagram 8-Pin CDIP 20144014 Top View (c) 2005 National Semiconductor Corporation DS201440 www.national.com LM6142QML 17 MHz Rail-to-Rail Input-Output Operational Amplifiers November 2005 LM6142QML Absolute Maximum Ratings (Note 1) Differential Input Voltage 15V (V+) + 0.3V, (V-) - 0.3V Voltage at Input/Output Pin Supply Voltage (V+ - V-) 35V 10mA 25mA Current at Input Pin Current at Output Pin (Note 4) Current at Power Supply Pin 50mA Lead Temperature 260C (soldering, 10 sec) -65C TA +150C Storage Temp. Range Maximum Junction Temperature (TJmax)(Note 2) 150C Thermal Resistance JA still Air 125C/W 500LF / Min Air Flow 63C/W JC 12C/W ESD Tolerance (Note 3) 3KV Recommended Operating Conditions(Note 1) 2.8V V+ 24V Supply Voltage -55C TA +125C Operating Temperature Range Quality Conformance Inspection Mil-Std-883, Method 5005 - Group A Subgroup Description Temp C 1 Static tests at 25 2 Static tests at 125 3 Static tests at -55 4 Dynamic tests at 25 5 Dynamic tests at 125 6 Dynamic tests at -55 7 Functional tests at 25 8A Functional tests at 125 8B Functional tests at -55 9 Switching tests at 25 10 Switching tests at 125 11 Switching tests at -55 12 Settling time at 25 13 Settling time at 125 14 Settling time at -55 www.national.com 2 LM6142QML 5.0V Electrical Characteristics DC Parameters The following conditions apply to all the following parameters, unless otherwise specified. DC: V+ = 5.0V, V- = 0V, VCM = VO = V+/2 and RL 100K to V+/2 Symbol Parameter Conditions Notes Min Input Offset Voltage VIO IIB Input Bias Current IIO 0V VCM 5V Common Mode Rejection Ratio 0V VCM 4V 0V VCM 5V 5V V+ 24V nit 1.0 mV 1 2.5 mV 2, 3 280 nA 1 526 nA 2, 3 30 nA 1 80 nA 2, 3 84 dB 1 78 dB 2, 3 66 dB 1 64 dB 2, 3 80 dB 1 Input Offset Current CMRR Subgroup Max PSRR Power Supply Rejection Ratio VCM Input Common-Mode Voltage Range AV Large Signal Voltage Gain RL = 10K 100 VO Output Swing RL = 100K 4.98 0.01 V 4 4.93 0.014 V 5, 6 4.86 0.1 V 4 4.77 0.133 V 5 4.8 0.133 V 6 mA 1 mA 2, 3 78 (Note 5) 0 5.0 33 Output Swing ISC Output Short Circuit Current RL = 2K Sourcing 10 2.0 Sinking 4.0 IS Supply Current 35 10 Per Amplifier dB 2, 3 V 1, 2, 3 V/mV 4 V/mV 5, 6 mA 1 35 mA 2, 3 800 A 1 880 A 2, 3 Max nit Subgroup AC Parameters The following conditions apply to all the following parameters, unless otherwise specified. AC: V+ = 5.0V, V- = 0V, VCM = VO = V+/2 and RL 100K to V+/2 Symbol +SR -SR GBW Parameter Slew Rate Slew Rate Gain-Bandwidth Product Conditions Notes Min -4V VI +4V, +VCC = 6V, -VCC -6V, RS = 1K, RL = 2K CO = 0F 15 V/S 4 9.5 V/S 5 11 V/S 6 +4V VI -4V, +VCC = 6V, -VCC -6V, RS = 1K, RL = 2K CO = 0F 15 V/S 4 9.5 V/S 5 11 V/S 6 = 50Khz 10 MHz 4 6.0 MHz 5, 6 3 www.national.com LM6142QML 2.8V Electrical Characteristics DC Parameters The following conditions apply to all the following parameters, unless otherwise specified. DC: V+ = 2.8V, V- = 0V, VCM = VO = V+/2 and RL 100K to V+/2 Symbol Parameter Conditions Notes Min nit 1.8 mV 1 4.3 mV 2, 3 250 nA 1 526 nA 2, 3 30 nA 1 80 nA 2, 3 72 dB 1 63 dB 2, 3 62 dB 1 58 dB 2, 3 72 dB 1 Input Offset Voltage VIO IIB Input Bias Current IIO Input Offset Current Common Mode Rejection Ratio 0V VCM 1.9V CMRR 0V VCM 2.8V 3V V+ 5V PSRR Power Supply Rejection Ratio VCM Input Common-Mode Voltage Range AV Large Signal Voltage Gain RL = 100K, VO = 1.1V VO Output Swing RL = 100K 58 (Note 5) 0.0 2.8 10 1.5 IS Supply Current Subgroup Max dB 2, 3 V 1, 2, 3 V/mV 4 V/mV 5, 6 2.76 0.08 V 4 2.35 0.112 V 5, 6 800 A 1 880 A 2, 3 Max nit Subgroup Per Amplifier AC Parameters The following conditions apply to all the following parameters, unless otherwise specified. AC: V+ = 2.8V, V- = 0V, VCM = VO = V+/2 and RL 100Kto V+/2 Symbol GBW Parameter Gain-Bandwidth Product www.national.com Conditions = 50KHz 4 Notes Min 3 MHz 4 1.5 MHz 5, 6 LM6142QML 24V Electrical Characteristics DC Parameters The following conditions apply to all the following parameters, unless otherwise specified. DC: V+ = 24V, V- = 0V, VCM = VO = V+/2 and RL 100K to V+/2 Symbol VIO VO IS Parameter Conditions Notes Min Input Offset Voltage Output Swing Supply Current RL = 10K 23.81 Per Amplifier Subgroup Max nit 2.0 mV 1 4.8 mV 2, 3 0.15 V 4 23.62 0.185 V 5, 6 1100 A 1 1150 A 2, 3 Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed test conditions. Note 2: The maximum power dissipation must be derated at elevated temperatures and is dictated by TJmax (maximum junction temperature), JA (package junction to ambient thermal resistance), and TA (ambient temperature). The maximum allowable power dissipation at any temperature is PDmax = (TJmax - TA)/JA or the number given in the Absolute Maximum Ratings, whichever is lower. Note 3: Human body model, 1.5k in series with 100pF. Note 4: Applies to both single-supply and split-supply operation. Continuous short circuit operation at elevated ambient temperature can result in exceeding the maximum allowed junction temperature of 150C. Note 5: Input common-mode voltage range is guaranteed by CMRR. 5 www.national.com LM6142QML Typical Performance Characteristics TA = 25C, RL = 10 k Unless Otherwise Specified Supply Current vs. Supply Voltage Offset Voltage vs. Supply Voltage 20144015 20144016 Bias Current vs. Supply Voltage Offset Voltage vs. VCM 20144017 20144018 Offset Voltage vs. VCM Offset Voltage vs. VCM 20144019 www.national.com 20144020 6 LM6142QML Typical Performance Characteristics TA = 25C, RL = 10 k Unless Otherwise Specified (Continued) Bias Current vs. VCM Bias Current vs. VCM 20144021 20144022 Bias Current vs. VCM Open-Loop Transfer Function 20144023 20144024 Open-Loop Transfer Function Open-Loop Transfer Function 20144025 20144026 7 www.national.com LM6142QML Typical Performance Characteristics TA = 25C, RL = 10 k Unless Otherwise Specified (Continued) Output Voltage vs. Source Current Output Voltage vs. Source Current 20144027 20144029 Output Voltage vs. Source Current Output Voltage vs. Sink Current 20144028 20144030 Output Voltage vs. Sink Current Output Voltage vs. Sink Current 20144031 www.national.com 20144032 8 LM6142QML Typical Performance Characteristics TA = 25C, RL = 10 k Unless Otherwise Specified (Continued) Gain and Phase vs. Load Gain and Phase vs. Load 20144033 20144034 Distortion + Noise vs. Frequency GBW vs. Supply 20144036 20144035 Open Loop Gain vs. Load, 3V Supply Open Loop Gain vs. Load, 5V Supply 20144037 20144038 9 www.national.com LM6142QML Typical Performance Characteristics TA = 25C, RL = 10 k Unless Otherwise Specified (Continued) Open Loop Gain vs. Load, 24V Supply Unity Gain Frequency vs. VS 20144040 20144039 CMRR vs. Frequency Crosstalk vs. Frequency 20144041 20144042 PSRR vs. Frequency Noise Voltage vs. Frequency 20144043 www.national.com 20144044 10 LM6142QML Typical Performance Characteristics TA = 25C, RL = 10 k Unless Otherwise Specified (Continued) Noise Current vs. Frequency NF vs. RSource 20144012 20144045 LM6142 Application Ideas Slew Rate vs. VIN VS = 5V The LM6142 brings a new level of ease of use to op amp system design. With greater than rail-to-rail input voltage range concern over exceeding the common-mode voltage range is eliminated. Rail-to-rail output swing provides the maximum possible dynamic range at the output. This is particularly important when operating on low supply voltages. The high gain-bandwidth with low supply current opens new battery powered applications, where high power consumption, previously reduced battery life to unacceptable levels. To take advantage of these features, some ideas should be kept in mind. ENHANCED SLEW RATE Unlike most bipolar op amps, the unique phase reversal prevention/speed-up circuit in the input stage causes the slew rate to be very much a function of the input signal amplitude. Figure 2 shows how excess input signal, is routed around the input collector-base junctions, directly to the current mirrors. The LM6142 input stage converts the input voltage change to a current change. This current change drives the current mirrors through the collectors of Q1-Q2, Q3-Q4 when the input levels are normal. If the input signal exceeds the slew rate of the input stage, the differential input voltage rises above two diode drops. This excess signal bypasses the normal input transistors, (Q1-Q4), and is routed in correct phase through the two additional transistors, (Q5, Q6), directly into the current mirrors. This rerouting of excess signal allows the slew-rate to increase by a factor of 10 to 1 or more. (See Figure 1.) As the overdrive increases, the op amp reacts better than a conventional op amp. Large fast pulses will raise the slewrate to around 30V to 60V/s. 20144007 FIGURE 1. This effect is most noticeable at higher supply voltages and lower gains where incoming signals are likely to be large. This new input circuit also eliminates the phase reversal seen in many op amps when they are overdriven. This speed-up action adds stability to the system when driving large capacitive loads. DRIVING CAPACITIVE LOADS Capacitive loads decrease the phase margin of all op amps. This is caused by the output resistance of the amplifier and the load capacitance forming an R-C phase lag network. This can lead to overshoot, ringing and oscillation. Slew rate limiting can also cause additional lag. Most op amps with a fixed maximum slew-rate will lag further and further behind when driving capacitive loads even though the differential input voltage raises. With the LM6142, the lag causes the slew rate to raise. The increased slew-rate keeps the output following the input much better. This effectively reduces phase lag. After the output has caught up with the input, the differential input voltage drops down and the amplifier settles rapidly. 11 www.national.com LM6142QML LM6142 Application Ideas (Continued) 20144006 FIGURE 2. These features allow the LM6142 to drive capacitive loads as large as 1000pF at unity gain and not oscillate. The scope photos (Figure 3 and Figure 4) above show the LM6142 driving a l000pF load. In Figure 3, the upper trace is with no capacitive load and the lower trace is with a 1000pF load. Here we are operating on 12V supplies with a 20 VPP pulse. Excellent response is obtained with a Cf of l0pF. In Figure 4, the supplies have been reduced to 2.5V, the pulse is 4 VPP and Cf is 39pF. The best value for the compensation capacitor is best established after the board layout is finished because the value is dependent on board stray capacity, the value of the feedback resistor, the closed loop gain and, to some extent, the supply voltage. Another effect that is common to all op amps is the phase shift caused by the feedback resistor and the input capacitance. This phase shift also reduces phase margin. This effect is taken care of at the same time as the effect of the capacitive load when the capacitor is placed across the feedback resistor. The circuit shown in Figure 5 was used for these scope photos. 20144008 FIGURE 3. 20144009 FIGURE 4. www.national.com 12 sion resistors reduces the CMR as well. Using two LM6142 amplifiers, all of these problems are eliminated. (Continued) In this example, amplifiers A and B act as buffers to the differential stage (Figure 6). These buffers assure that the input impedance is over 100M and they eliminate the requirement for precision matched resistors in the input stage. They also assure that the difference amp is driven from a voltage source. This is necessary to maintain the CMR set by the matching of R1-R2 with R3-R4. 20144010 FIGURE 5. Typical Applications ANALOG TO DIGITAL CONVERTER BUFFER The high capacitive load driving ability, rail-to-rail input and output range with the excellent CMR of 82 dB, make the LM6142a good choice for buffering the inputs of A to D converters. 20144013 FIGURE 6. The gain is set by the ratio of R2/R1 and R3 should equal R1 and R4 equal R2. Making R4 slightly smaller than R2 and adding a trim pot equal to twice the difference between R2 and R4 will allow the CMR to be adjusted for optimum. With both rail to rail input and output ranges, the inputs and outputs are only limited by the supply voltages. Remember that even with rail-to-rail output, the output can not swing past the supplies so the combined common mode voltage plus the signal should not be greater than the supplies or limiting will occur. 3 OP AMP INSTRUMENTATION AMP WITH RAIL-TO-RAIL INPUT AND OUTPUT Using two LM6142 amplifiers, a 3 op amp instrumentation amplifier with rail-to-rail inputs and rail to rail output can be made. These features make these instrumentation amplifiers ideal for single supply systems. Some manufacturers use a precision voltage divider array of 5 resistors to divide the common-mode voltage to get an input range of rail-to-rail or greater. The problem with this method is that it also divides the signal, so to even get unity gain, the amplifier must be run at high closed loop gains. This raises the noise and drift by the internal gain factor and lowers the input impedance. Any mismatch in these preci- SPICE MACROMODEL A SPICE macromodel of this and many other National Semiconductor op amps is available at no charge from the NSC Customer Response Group at 800-272-9959. 13 www.national.com LM6142QML LM6142 Application Ideas LM6142QML Revision History Section Date Released Revision Section Originator Changes 11/08/05 A New release to the corporate format L. Lytle 1 MDS datasheet converted into standard corporate format. MNLM6142-X Rev 4A1 to be archived. www.national.com 14 inches (millimeters) unless otherwise noted 8-Pin Cerdip Dual-In-Line Package NS Package Number J08A National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. For the most current product information visit us at www.national.com. LIFE SUPPORT POLICY NATIONAL'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. BANNED SUBSTANCE COMPLIANCE National Semiconductor manufactures products and uses packing materials that meet the provisions of the Customer Products Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain no ``Banned Substances'' as defined in CSP-9-111S2. Leadfree products are RoHS compliant. National Semiconductor Americas Customer Support Center Email: new.feedback@nsc.com Tel: 1-800-272-9959 www.national.com National Semiconductor Europe Customer Support Center Fax: +49 (0) 180-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Francais Tel: +33 (0) 1 41 91 8790 National Semiconductor Asia Pacific Customer Support Center Email: ap.support@nsc.com National Semiconductor Japan Customer Support Center Fax: 81-3-5639-7507 Email: jpn.feedback@nsc.com Tel: 81-3-5639-7560 LM6142QML 17 MHz Rail-to-Rail Input-Output Operational Amplifiers Physical Dimensions