LM146/LM346 Programmable Quad Operational Amplifiers General Description Features The LM146 series of quad op amps consists of four independent, high gain, internally compensated, low power, programmable amplifiers. Two external resistors (RSET) allow the user to program the gain bandwidth product, slew rate, supply current, input bias current, input offset current and input noise. For example, the user can trade-off supply current for bandwidth or optimize noise figure for a given source resistance. In a similar way, other amplifier characteristics can be tailored to the application. Except for the two programming pins at the end of the package, the LM146 pin-out is the same as the LM124 and LM148. (ISET = 10 µA) n Programmable electrical characteristics n Battery-powered operation n Low supply current: 350 µA/amplifier n Guaranteed gain bandwidth product: 0.8 MHz min n Large DC voltage gain: 120 dB n Low noise voltage: 28 n Wide power supply range: ± 1.5V to ± 22V n Class AB output stage–no crossover distortion n Ideal pin out for Biquad active filters n Input bias currents are temperature compensated Connection Diagram PROGRAMMING EQUATIONS Total Supply Current = 1.4 mA (ISET/10 µA) Gain Bandwidth Product = 1 MHz (ISET/10 µA) Slew Rate = 0.4V/µs (ISET/10 µA) Input Bias Current ≅ 50 nA (ISET/10 µA) ISET = Current into pin 8, pin 9 (see schematic-diagram) Dual-In-Line Package DS005654-1 Top View Order Number LM146J, LM146J/883, LM346M or LM346N See NS Package Number J16A, M16A or N16A © 1999 National Semiconductor Corporation DS005654 www.national.com LM146/LM346 Programmable Quad Operational Amplifiers May 1999 Schematic Diagram DS005654-2 www.national.com 2 Absolute Maximum Ratings (Notes 1, 5) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. LM146 LM346 ± 22V ± 18V Supply Voltage ± 30V ± 30V Differential Input Voltage (Note 1) ± 15V ± 15V CM Input Voltage (Note 1) Power Dissipation (Note 2) 900 mW 500 mW Output Short-Circuit Duration (Note 3) Continuous Continuous Operating Temperature Range −55˚C to +125˚C 0˚C to +70˚C Maximum Junction Temperature 150˚C 100˚C Storage Temperature Range −65˚C to +150˚C −65˚C to +150˚C Lead Temperature (Soldering, 10 seconds) 260˚C 260˚C Thermal Resistance (θjA), (Note 2) Cavity DIP (J) Pd 900 mW 900 mW 100˚C/W 100˚C/W θjA 115˚C/W Small Outline (M) θjA Molded DIP (N) Pd 500 mW 90˚C/W θjA Soldering Information Dual-In-Line Package Soldering (10 seconds) +260˚C +260˚C Small Outline Package Vapor Phase (60 seconds) +215˚C +215˚C Infrared (15 seconds) +220˚C +220˚C See AN-450 “Surface Mounting Methods and Their Effect on Product Reliability” for other methods of soldering surface mount devices. ESD rating is to be determined. DC Electrical Characteristics (VS = ± 15V, ISET = 10 µA), (Note 4) Parameter Conditions LM146 Min Input Offset Voltage Input Offset Current Input Bias Current Supply Current (4 Op Amps) Large Signal Voltage Gain VCM = 0V, RS≤50Ω, TA = 25˚C VCM = 0V, TA = 25˚C VCM = 0V, TA = 25˚C TA = 25˚C RL = 10 kΩ, ∆VOUT = ± 10V, TA = 25˚C Input CM Range TA = 25˚C CM Rejection Ratio Power Supply Rejection Ratio RS≤10 kΩ, TA = 25˚C RS≤10 kΩ, TA = 25˚C, Output Voltage Swing VS = ± 5 to ± 15V RL≥10 kΩ, TA = 25˚C Short-Circuit Gain Bandwidth Product TA = 25˚C TA = 25˚C Typ LM346 Max Min Typ Units Max 0.5 5 0.5 6 2 20 2 100 mV nA 50 100 50 250 nA 1.4 2.0 1.4 2.5 mA 100 1000 50 1000 ± 13.5 ± 14 ± 13.5 ± 14 V 80 100 70 100 dB 80 100 74 100 dB ± 12 ± 14 ± 12 ± 14 5 20 5 20 0.8 1.2 0.5 1.2 35 V/mV V 35 mA MHz 60 60 Deg Slew Rate TA = 25˚C TA = 25˚C 0.4 0.4 V/µs Input Noise Voltage f = 1 kHz, TA = 25˚C 28 28 Channel Separation RL = 10 kΩ, ∆VOUT = 0V to ± 12V, TA = 25˚C 120 120 dB Input Resistance TA = 25˚C 1.0 1.0 MΩ Input Capacitance TA = 25˚C VCM = 0V, RS≤50Ω 2.0 2.0 Phase Margin Input Offset Voltage 0.5 3 6 0.5 pF 7.5 mV www.national.com DC Electrical Characteristics (Continued) (VS = ± 15V, ISET = 10 µA), (Note 4) Parameter Conditions LM146 Min VCM = 0V VCM = 0V Input Offset Current Input Bias Current Supply Current (4 Op Amps) RL = 10 kΩ, ∆VOUT = ± 10V Large Signal Voltage Gain LM346 Typ Max Min Typ Units Max 2 25 2 100 nA 50 100 50 250 nA 1.7 2.2 1.7 2.5 50 1000 25 1000 mA V/mV ± 13.5 ± 14 ± 13.5 ± 14 V CM Rejection Ratio RS≤50Ω 70 100 70 100 dB Power Supply Rejection Ratio RS≤50Ω, VS = ± 5V to ± 15V 76 100 74 100 dB Output Voltage Swing RL≥10 kΩ ± 12 ± 14 ± 12 ± 14 V Input CM Range DC Electrical Characteristic (VS = ± 15V, ISET = 10 µA) Parameter Conditions LM146 Min LM346 Typ Max 5 Min Units Typ Max 0.5 7 Input Offset Voltage VCM = 0V, RS≤50Ω, 0.5 Input Bias Current 7.5 20 7.5 100 nA Supply Current (4 Op Amps) TA = 25˚C VCM = 0V, TA = 25˚C TA = 25˚C 140 250 140 300 µA Gain Bandwidth Product TA = 25˚C 80 100 50 100 mV kHz DC Electrical Characteristics (VS = ± 1.5V, ISET = 10 µA) Parameter Conditions LM146 Min Input Offset Voltage VCM = 0V, RS≤50Ω, Input CM Range TA = 25˚C TA = 25˚C CM Rejection Ratio Output Voltage Swing RS≤50Ω, TA = 25˚C RL≥10 kΩ, TA = 25˚C LM346 Typ Max 0.5 5 ± 0.7 Min Max 0.5 7 ± 0.7 80 ± 0.6 mV V 80 ± 0.6 Units Typ dB V Note 1: For supply voltages less than ± 15V, the absolute maximum input voltage is equal to the supply voltage. Note 2: The maximum power dissipation for these devices must be derated at elevated temperatures and is dictated by TjMAX, θjA, and the ambient temperature, TA. The maximum available power dissipation at any temperature is Pd = (TjMAX - TA)/θjA or the 25˚C PdMAX, whichever is less. Note 3: Any of the amplifier outputs can be shorted to ground indefinitely; however, more than one should not be simultaneously shorted as the maximum junction temperature will be exceeded. Note 4: These specifications apply over the absolute maximum operating temperature range unless otherwise noted. Note 5: Refer to RETS146X for LM146J military specifications. www.national.com 4 Typical Performance Characteristics Input Bias Current vs ISET Supply Current vs ISET DS005654-44 Open Loop Voltage Gain vs ISET DS005654-45 DS005654-46 Slew Rate vs ISET Gain Bandwidth Product vs ISET Phase Margin vs ISET DS005654-47 DS005654-49 DS005654-48 Input Offset Voltage vs ISET Common-Mode Rejection Ratio vs ISET Power Supply Rejection Ratio vs ISET DS005654-51 DS005654-50 5 DS005654-52 www.national.com Typical Performance Characteristics Open Voltage Swing vs Supply Voltage (Continued) Input Voltage Range vs Supply Voltage Input Bias Current vs Input Common-Mode Voltage DS005654-53 DS005654-54 DS005654-55 Input Bias Current vs Temperature Input Offset Current vs Temperature DS005654-56 Open Loop Voltage Gain vs Temperature Supply Current vs Temperature DS005654-57 Gain Bandwidth Product vs Temperature Slew Rate vs Temperature DS005654-20 DS005654-21 www.national.com 6 DS005654-58 DS005654-22 Typical Performance Characteristics Input Noise Voltage vs Frequency (Continued) Input Noise Current vs Frequency Power Supply Rejection Ratio vs Frequency DS005654-24 DS005654-23 Voltage Follower Pulse Response DS005654-25 Voltage Follower Transient Response DS005654-27 DS005654-26 Transient Response Test Circuit DS005654-6 Application Hints Avoid reversing the power supply polarity; the device will fail. Common-Mode Input Voltage: The negative common-mode voltage limit is one diode drop above the negative supply voltage. Exceeding this limit on either input will result in an output phase reversal. The positive common-mode limit is typically 1V below the positive supply voltage. No output phase reversal will occur if this limit is exceeded by either input. Output Voltage Swing vs ISET: For a desired output voltage swing the value of the minimum load depends on the positive and negative output current capability of the op amp. The maximum available positive output current, (ICL+), of the device increases with ISET whereas the negative output current (ICL−) is independent of ISET. Figure 1 illustrates the above. DS005654-7 FIGURE 1. Output Current Limit vs ISET 7 www.national.com Application Hints power decreases proportionally and the VOSremains constant. The usable GBW range of the op amp is 10 kHz to 3.5−4 MHz. (Continued) Input Capacitance: The input capacitance, CIN, of the LM146 is approximately 2 pF; any stray capacitance, CS, (due to external circuit circuit layout) will add to CIN. When resistive or active feedback is applied, an additional pole is added to the open loop frequency response of the device. For instance with resistive feedback (Figure 2), this pole occurs at 1⁄2π (R1||R2) (CIN + CS). Make sure that this pole occurs at least 2 octaves beyond the expected −3 dB frequency corner of the closed loop gain of the amplifier; if not, place a lead capacitor in the feedback such that the time constant of this capacitor and the resistance it parallels is equal to the RI(CS + CIN), where RI is the input resistance of the circuit. DS005654-8 DS005654-9 FIGURE 3. LM146 Typical Characteristics FIGURE 2. Low Power Supply Operation: The quad op amp operates down to ± 1.3V supply. Also, since the internal circuitry is biased through programmable current sources, no degradation of the device speed will occur. Speed vs Power Consumption: LM146 vs LM4250 (single programmable). Through Figure 4, we observe that the LM146’s power consumption has been optimized for GBW products above 200 kHz, whereas the LM4250 will reach a GBW of no more than 300 kHz. For GBW products below 200 kHz, the LM4250 will consume less power. Temperature Effect on the GBW: The GBW (gain bandwidth product), of the LM146 is directly proportional to ISET and inversely proportional to the absolute temperature. When using resistors to set the bias current, ISET, of the device, the GBW product will decrease with increasing temperature. Compensation can be provided by creating an ISET current directly proportional to temperature (see typical applications). Isolation Between Amplifiers: The LM146 die is isothermally layed out such that crosstalk between all 4 amplifiers is in excess of −105 dB (DC). Optimum isolation (better than −110 dB) occurs between amplifiers A and D, B and C; that is, if amplifier A dissipates power on its output stage, amplifier D is the one which will be affected the least, and vice versa. Same argument holds for amplifiers B and C. LM146 Typical Performance Summary: The LM146 typical behaviour is shown in Figure 3. The device is fully predictable. As the set current, ISET, increases, the speed, the bias current, and the supply current increase while the noise DS005654-10 FIGURE 4. LM146 vs LM4250 www.national.com 8 Typical Applications Dual Supply or Negative Supply Blasing Single (Positive) Supply Blasing DS005654-39 DS005654-11 Current Source Blasing with Temperature Compensation Blasing all 4 Amplifiers with Single Current Source DS005654-40 • The LM334 provides an ISET directly proportional to absolute temperature. This cancels the slight GBW product Temperature coefficient of the LM346. DS005654-41 • For ISET1 ≅ ISET2 resistors R1 and R2 are not required if a slight error between the 2 set currents can be tolerated. If not, then use R1 = R2 to create a 100 mV drop across these resistors. 9 www.national.com Active Filters Applications Basic (Non-Inverting “State Variable”) Active Filter Building Block DS005654-12 DS005654-33 Note. All resistor values are given in ohms. DS005654-34 DS005654-13 www.national.com 10 Active Filters Applications (Continued) DS005654-35 A Simple-to-Design BP, LP Filter Building Block DS005654-14 • If resistive biasing is used to set the LM346 performance, the Qo of this filter building block is nearly insensitive to the op amp’s GBW product temperature drift; it has also better noise performance than the state variable filter. Circuit Synthesis Equations DS005654-36 • For the eventual use of amplifier C, see comments on the previous page. 11 www.national.com Active Filters Applications (Continued) A 3-Amplifier Notch Filter (or Elliptic Filter Building Block) DS005654-15 Circuit Synthesis Equations DS005654-37 • For nothing but a notch output: RIN = R, C' = C. Capacitorless Active Filters (Basic Circuit) DS005654-16 www.national.com 12 Active Filters Applications (Continued) DS005654-38 1. Pick up a convenient value for b; (b < 1) 2. Adjust Qo through R5 3. Adjust Ho(BP) through R4 4. Adjust fo through RSET. This adjusts the unity gain frequency (fu) of the op amp. A 4th Order Butterworth Low Pass Capacitorless Filter DS005654-17 Ex: fc = 20 kHz, Ho (gain of the filter) = 1, Q01 = 0.541, Qo2 = 1.306. • Since for this filter the GBW product of all 4 amplifiers has been designed to be the same (z1 MHz) only one current source can be used to bias the circuit. Fine tuning can be further accomplished through Rb. Miscellaneous Applications A Unity Gain Follower with Bias Current Reduction DS005654-18 • For better performance, use a matched NPN pair. 13 www.national.com Miscellaneous Applications (Continued) Circuit Shutdown DS005654-42 • By pulling the SET pin(s) to V− the op amp(s) shuts down and its output goes to a high impedance state. According to this property, the LM346 can be used as a very low speed analog switch. Voice Activated Switch and Amplifier DS005654-43 www.national.com 14 Miscellaneous Applications (Continued) X10 Micropower Instrumentation Amplifier with Buffered Input Guarding DS005654-19 • CMRR: 100 dB (typ) • Power dissipation: 0.4 mW 15 www.national.com Physical Dimensions inches (millimeters) unless otherwise noted Cavity Dual-In-Line Package (J) Order Number LM146J, LM146J/883 NS Package Number J16A S.O. Package (M) Order Number LM346M NS Package Number M16A www.national.com 16 LM146/LM346 Programmable Quad Operational Amplifiers Physical Dimensions inches (millimeters) unless otherwise noted (Continued) Molded Dual-In-Line Package (N) Order Number LM346N NS Package Number N16A 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. National Semiconductor Corporation Americas Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: [email protected] www.national.com National Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: [email protected] Deutsch Tel: +49 (0) 1 80-530 85 85 English Tel: +49 (0) 1 80-532 78 32 Français Tel: +49 (0) 1 80-532 93 58 Italiano Tel: +49 (0) 1 80-534 16 80 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. 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