LP324N

LP324/LP2902 Micropower Quad Operational Amplifier July 2001 LP324/LP2902 Micropower Quad Operational Amplifier General Description The LP324 series consists of four independent, high gain internally compensated micropower operational amplifiers. These amplifiers are specially suited for operation in battery systems while maintaining good input specifications, and extremely low supply current drain. In addition, the LP324 has an input common mode range, and output source range which includes ground, making it ideal in single supply applications. These amplifiers are ideal in applications which include portable instrumentation, battery backup equipment, and other circuits which require good DC performance and low supply current. Features n n n n n n n n Low supply current: 85µA (typ) Low offset voltage: 2mV (typ) Low input bias current: 2nA (typ) Input common mode to GND Interfaces to CMOS logic Wide supply range: 3V < V+ < 32V Small Outline Package available Pin-for-pin compatible with LM324 Connection Diagrams Dual-In-Line (N) and SO (M) 14-Pin TSSOP 00856201 Order Number LP324M or LP2902M See NS Package Number M14A Order Number LP324N or LP2902N See NS Package Number N14A 00856240 Order Number LP324MT and LP324MTX See NS Package Number MTC14 Simplified Schematic 00856202 © 2001 National Semiconductor Corporation DS008562 www.national.com LP324/LP2902 Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage LP324 LP2902 Differential Input Voltage LP324 LP2902 Input Voltage (Note 2) LP324 LP2902 Output Short-Circuit to GND (One Amplifier) (Note 3) −0.3V to 32V −0.3V to 26V Continuous 32V 26V 32V or ± 16V 26V or ± 13V V+ ≤ 15V and TA = 25˚C ESD Susceptibility (Note 10) ± 500V Operating Conditions TJMAX θJA (Note 4) MT Package N Package M Package Operating Temp. Range Storage Temp. Range Soldering Information Wave Soldering(10sec) Convection or Infrared(20sec) 260˚C(lead temp.) 235˚C 154˚C/W 90˚C/W 140˚C/W (Note 5) −65˚C≤TJ≤ 150˚C 150˚C Electrical Characteristics (Note 6) LP2902 (Note 9) Symbol Parameter Conditions Typ VOS IB IOS AVOL CMRR PSRR IS VO Input Offset Voltage Input Bias Current Input Offset Current Voltage Gain Common Mode Rej. Ratio Power Supply Rej. Ratio Supply Current Output Voltage Swing RL = 10k to GND V+ = 30V V+ = 30V, 0V ≤ VCM VCM < V+− 1.5 V+ = 5V to 30V RL = ∞ IL = 350µA to GND VCM = 0V IL = 350µA to V+ VCM = 0V IOUT Source IOUT Sink IOUT Sink Output Source Current Output Sink Current Output Sink Current VO = 3V VIN (diff) = 1V VO = 1.5V VIN (diff) = 1V VO = 1.5V VCM = 0V VIN (diff) = 1V VIN (diff) = 1V 2 2 0.5 70 90 90 85 3.6 0.7 10 5 4 20 15 10 10 Tested Limit (Note 7) 4 20 4 40 80 80 150 3.4 0.8 7 4 2 25 35 30 Design Limit (Note 8) 10 40 8 30 75 75 250 V+−1.9V 1.0 4 3 1 35 45 2 2 0.2 100 90 90 85 3.6 0.7 10 5 4 20 15 10 10 Typ LP324 Tested Limit (Note 7) 4 10 2 50 80 80 150 3.4 0.8 7 4 2 25 35 30 Design Limit (Note 8) 9 20 4 40 75 75 250 V+−1.9V 1.0 4 3 1 35 45 mV (Max) nA (Max) nA (Max) V/mV (Min) dB (Min) dB (Min) µA (Max) V (Min) V (Max) mA (Min) mA (Min) mA (Min) mA (Max) mA (Max) µV/C˚ pA/C˚ Units Limits ISOURCE Output Short to GND ISINK VOS Drift IOS Drift www.national.com Output Short to V+ 2 LP324/LP2902 Electrical Characteristics (Note 6) Symbol Parameter Conditions (Continued) LP2902 (Note 9) Tested Typ Limit (Note 7) Design Limit (Note 8) 100 50 Typ LP324 Tested Limit (Note 7) Design Limit (Note 8) KHz V/mS Units Limits GBW SR Gain Bandwidth Product Slew Rate 100 50 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. Note 2: The input voltage is not allowed to go more than −0.3V below V− (GND) as this will turn on a parasitic transistor causing large currents to flow through the device. Note 3: Short circuits from the output to GND can cause excessive heating and eventual destruction. The maximum sourcing output current is approximately 30 mA independent of the magnitude of V+. At values of supply voltage in excess of 15 VDC, continuous short-circuit to GND can exceed the power dissipation ratings (particularly at elevated temperatures) and cause eventual destruction. Destructive dissipation can result from simultaneous shorts on all amplifiers. Note 4: For operation at elevated temperatures, these devices must be derated based on a thermal resistance of θJA and TJ max. TJ = TA + θJAPD. Note 5: The LP2902 may be operated from −40˚C ≤ TA ≤ +85˚C, and the LP324 may be operated from 0˚C ≤ TA ≤ +70˚C. Note 6: Boldface numbers apply at temperature extremes. All other numbers apply only at TA = TJ = 25˚C, V+ = 5V, Vcm = V/2, and RL =100k connected to GND unless otherwise specified. Note 7: Guaranteed and 100% production tested. Note 8: Guaranteed (but not 100% production tested) over the operating supply voltage range (3.0V to 32V for the LP324, LP324, and 3.0V to 26V for the LP2902), and the common mode range (0V to V+ −1.5V), unless otherwise specified. These limits are not used to calculate outgoing quality levels. Note 9: The LP2902 operating supply range is 3V to 26V, and is not tested above 26V. Note 10: The test circuit used consists of the human body model of 100 pF in series with 1500Ω. 3 www.national.com LP324/LP2902 Typical Performance Curves Input Voltage Range Input Current 00856221 00856222 Supply Current Voltage Gain 00856223 00856224 Open Loop Frequency Response Power Supply Rejection Ratio 00856225 00856226 www.national.com 4 LP324/LP2902 Typical Performance Curves Voltage Follower Pulse Response (Continued) Voltage Follower Pulse Response (Small Signal) 00856227 00856228 Common Mode Rejection Ratio Large Signal Frequency Response 00856229 00856230 Output Characteristics Current Sourcing Output Characteristics Current Sinking 00856231 00856232 5 www.national.com LP324/LP2902 Typical Performance Curves (Continued) Current Limiting 00856233 Application Hints The LP324 series is a micro-power pin-for-pin equivalent to the LM324 op amps. Power supply current, input bias current, and input offset current have all been reduced by a factor of 10 over the LM324. Like its predecessor, the LP324 series op amps can operate on single supply, have true-differential inputs, and remain in the linear mode with an input common-mode voltage of 0 VDC. The pinouts of the package have been designed to simplify PC board layouts. Inverting inputs are adjacent to outputs for all of the amplifiers and the outputs have also been placed at the corners of the package (pins 1, 7, 8, and 14). Precautions should be taken to insure that the power supply for the integrated circuit never becomes reversed in polarity or the unit is not inadvertently installed backwards in the test socket as an unlimited current surge through the resulting forward diode within the IC could destroy the unit. Large differential input voltages can be easily accommodated and, as input differential voltage protection diodes are not needed, no large input currents result from large differential input voltages. The differential input voltage may be larger than V+ without damaging the device. Protection should be provided to prevent the input voltages from going negative more than −0.3 VDC (at 25˚C). An input clamp diode with a resistor to the IC input terminal can be used. The amplifiers have a class B output stage which allows the amplifiers to both source and sink output currents. In applications where crossover distortion is undesirable, a resistor should be used from the output of the amplifier to ground. The resistor biases the output into class A operation. The LP324 has improved stability margin for driving capacitive loads. No special precautions are needed to drive loads in the 50 pF to 1000 pF range. It should be noted however that since the power supply current has been reduced by a factor of 10, so also has the slew rate and gain bandwidth product. This reduction can cause reduced performance in AC applications where the LM324 is being replaced by an LP324. Such situations usually occur when the LM324 has been operated near its power bandwidth. Output short circuits either to ground or to the positive power supply should be of short time duration. Units can be destroyed, not as a result of the short circuit current causing www.national.com 6 metal fusing, but rather due to the large increase in IC chip dissipation which will cause eventual failure due to excessive junction temperatures. For example: If all four amplifiers were simultaneously shorted to ground on a 10V supply the junction temperature would rise by 110˚C. Exceeding the negative common-mode limit on either input will cause a reversal of phase to the output and force the amplifier to the corresponding high or low state. Exceeding the negative common-mode limit on both inputs will force the amplifier output to a high state. Exceeding the positive common-mode limit on a single input will not change the phase of the output. However, if both inputs exceed the limit, the output of the amplifier will be forced to a low state. In neither case does a latch occur since returning the input within the common mode range puts the input stage and thus the amplifier in a normal operating mode. The circuits presented in the section on typical applications emphasize operation on only a single power supply voltage. If complementary power supplies are available, all of the standard op amp circuits can be used. In general, introducing a pseudo-ground (a bias voltage reference to V+/2) will allow operation above and below this value in single power supply systems. Many application circuits are shown which take advantage of the wide input common-mode voltage range which includes ground. In most cases, input biasing is not required and input voltages which range to ground can easily be accommodated. Driving CMOS 00856203 LP324/LP2902 Application Hints (Continued) Differential Integrator Comparator with Hysteresis 00856206 Non-Inverting Amplifier 00856209 Howland Current Pump 00856204 Adder/Subtractor 00856210 Bridge Current Amplifier 00856207 Unity Gain Buffer 00856205 Positive Integrator 00856211 µ Power Current Source 00856208 00856212 7 www.national.com LP324/LP2902 Application Hints (Continued) Lowpass Filter 00856213 1 kHz Bandpass Active Filter 00856214 Band-Reject Filter 00856215 www.national.com 8 LP324/LP2902 Application Hints (Continued) Pulse Generator 00856216 Window Comparator 00856217 9 www.national.com LP324/LP2902 Physical Dimensions unless otherwise noted inches (millimeters) S.O. Package (M) Order Number LP324M, LP324MX, LP2902M or LP2902MX NS Package Number M14A Dual-in-Line Package (N) Order Number LP324N or LP2902N NS Package Number N14A www.national.com 10 LP324/LP2902 Micropower Quad Operational Amplifier Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 14-Pin TSSOP Order Number LP324MT and LP324MTX NS Package Number MTC14 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. 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