LM614 Quad Operational Amplifier and Adjustable Reference General Description Features The LM614 consists of four op-amps and a programmable voltage reference in a 16-pin package. The op-amp out-performs most single-supply op-amps by providing higher speed and bandwidth along with low supply current. This device was specifically designed to lower cost and board space requirements in transducer, test, measurement and data acquisition systems. Combining a stable voltage reference with four wide output swing op-amps makes the LM614 ideal for single supply transducers, signal conditioning and bridge driving where large common-mode-signals are common. The voltage reference consists of a reliable band-gap design that maintains low dynamic output impedance (1X typical), excellent initial tolerance (0.6%), and the ability to be programmed from 1.2V to 6.3V via two external resistors. The voltage reference is very stable even when driving large capacitive loads, as are commonly encountered in CMOS data acquisition systems. As a member of National’s new Super-Block TM family, the LM614 is a space-saving monolithic alternative to a multichip solution, offering a high level of integration without sacrificing performance. Op Amp Y Low operating current 300 mA Y Wide supply voltage range 4V to 36V Y Wide common-mode range Vb to (V a b 1.8V) Y Wide differential input voltage g 36V Y Available in plastic package rated for Military Temperature Range Operation Reference Y Adjustable output voltage 1.2V to 6.3V Y Tight initial tolerance available g 0.6% Y Wide operating current range 17 mA to 20 mA Y Tolerant of load capacitance Applications Y Y Y Y Transducer bridge driver and signal processing Process and mass flow control systems Power supply voltage monitor Buffered voltage references for A/D’s Connection Diagram TL/H/9326 – 1 Ordering Information Reference Tolerance & VOS g 0.6% @ 80 ppm/§ C max VOS s 3.5 mV max Temperature Range NSC Drawing Military b 55§ C s TA s a 125§ C Industrial b 40§ C s TA s a 85§ C Commercial 0§ C s TA s a 70§ C Package LM614AMN LM614AIN Ð 16-pin Molded DIP N16E LM614AMJ/883 (Note 13) Ð Ð 16-pin Ceramic DIP J16A LM614MN LM614BIN LM614CN 16-pin Molded DIP N16E Ð LM614WM LM614CWM 16-pin Wide Surface Mount M16B g 2.0% @ 150 ppm/§ C max VOS s 5.0 mV Super-BlockTM is a trademark of National Semiconductor Corporation. C1996 National Semiconductor Corporation TL/H/9326 RRD-B30M56/Printed in U. S. A. LM614 Quad Operational Amplifier and Adjustable Reference February 1995 Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. Voltage on Any Pins except VR (referred to Vb pin) (Note 2) (Note 3) 36V (Max) b 0.3V (Min) Current through Any Input Pin & VR Pin Differential Input Voltage Military and Industrial Commercial Storage Temperature Range g 20 mA Maximum Junction Temperature 150§ C Thermal Resistance, Junction-to-Ambient (Note 4) N Package WM Package 100§ C 150§ C Soldering Information (Soldering, 10 seconds) N Package WM Package 260§ C 220§ C ESD Tolerance (Note 5) g 1kV Operating Temperature Range g 36V g 32V LM614AI, LM614I, LM614BI LM614AM, LM614M LM614C b 65§ C s TJ s a 150§ C b 40§ C s TJ s a 85§ C b 55§ C s TJ s a 125§ C 0§ C s TJ s a 70§ C Electrical Characteristics These specifications apply for Vb e GND e 0V, V a e 5V, VCM e VOUT e 2.5V, IR e 100 mA, FEEDBACK pin shorted to GND, unless otherwise specified. Limits in standard typeface are for TJ e 25§ C; limits in boldface type apply over the Operating Temperature Range. Symbol Parameter IS Total Supply Current VS Supply Voltage Range Conditions RLOAD e % , 4V s V a s 36V (32V for LM614C) Typical (Note 6) LM614AM LM614AI Limits (Note 7) LM614M LM614BI LM614I LM614C Limits (Note 7) Units 450 550 940 1000 1000 1070 mA max mA max 2.2 2.9 2.8 3 2.8 3 V min V min 46 43 36 36 32 32 V max V max OPERATIONAL AMPLIFIER VOS1 VOS Over Supply 4V s V a s 36V (4V s V a s 32V for LM614C) 1.5 2.0 3.5 6.0 5.0 7.0 mV max mV max VOS2 VOS Over VCM VCM e 0V through VCM e (V a b 1.8V), V a e 30V 1.0 1.5 3.5 6.0 5.0 7.0 mV max mV max VOS3 DT Average VOS Drift (Note 7) IB Input Bias Current 10 11 25 30 35 40 nA max nA max IOS Input Offset Current 0.2 0.3 4 5 4 5 nA max nA max IOS1 DT Average Offset Drift Current RIN Input Resistance mV/§ C max 15 4 pA/§ C Differential 1800 MX Common-Mode 3800 MX CIN Input Capacitance Common-Mode Input 5.7 pF en Voltage Noise f e 100 Hz, Input Referred 74 nV/0Hz In Current Noise f e 100 Hz, Input Referred 58 CMRR Common-Mode Rejection Ratio V a e 30V, 0V s VCM s (V a b 1.8V), CMRR e 20 log (DVCM/DVOS) 95 90 80 75 75 70 dB min dB min PSRR Power Supply Rejection Ratio 4V s V a s 30V, VCM e V a /2, PSRR e 20 log (DV a /DVOS) 110 100 80 75 75 70 dB min dB min AV Open Loop Voltage Gain RL e 10 kX to GND, V a e 30V, 5V s VOUT s 25V 500 50 100 40 94 40 V/mV min http://www.national.com 2 fA/0Hz Electrical Characteristics (Continued) These specifications apply for Vb e GND e 0V, V a e 5V, VCM e VOUT e 2.5V, IR e 100 mA, FEEDBACK pin shorted to GND, unless otherwise specified. Limits in standard typeface are for TJ e 25§ C; limits in boldface type apply over the Operating Temperature Range. Symbol SR Parameter Slew Rate Typical (Note 6) Conditions V a e 30V (Note 8) LM614AM LM614AI Limits (Note 8) LM614M LM614BI LM614I LM614C Limits (Note 8) g 0.70 g 0.55 g 0.50 g 0.65 g 0.45 g 0.45 0.8 0.52 Units V/ms GBW Gain Bandwidth CL e 50 pF MHz MHz VO1 Output Voltage Swing High RL e 10 kX to GND V a e 36V (32V for LM614C) V a b 1.4 V a b 1.6 V a b 1.7 V a b 1.9 V a b 1.8 V a b 1.9 V min V min VO2 Output Voltage Swing Low RL e 10 kX to V a V a e 36V (32V for LM614C) Vb a 0.8 Vb a 0.9 Vb a 0.9 Vb a 1.0 Vb a 0.95 Vb a 1.0 V max V max IOUT Output Source VOUT e 2.5V, V a IN e 0V, VbIN e b0.3V 25 15 20 13 16 13 mA min mA min ISINK Output Sink Current VOUT e 1.6V, V a IN e 0V, VbIN e 0.3V 17 9 14 8 13 8 mA min mA min ISHORT Short Circuit Current VOUT e 0V, V a IN e 3V, VbIN e 2V, Source 30 40 50 60 50 60 mA max mA max VOUT e 5V, V a IN e 2V, VbIN e 3V, Sink 30 32 60 80 70 90 mA max mA max VOLTAGE REFERENCE VR Voltage Reference (Note 9) 1.244 1.2365 1.2515 ( g 0.6%) 1.2191 1.2689 ( g 2.0%) V min V max DVR DT Average Temperature Drift (Note 10) 10 80 150 PPM/§ C max DVR DTJ Hysteresis (Note 11) DVR DIR VR Change with Current VR(100 mA) b VR(17 mA) 0.05 0.1 1 1.1 1 1.1 mV max mV max VR(10 mA) b VR(100 mA) (Note 12) 1.5 2.0 5 5.5 5 5.5 mV max mV max 3.2 mV/§ C R Resistance DVR(10 x 0.1 mA)/9.9 mA DVR(100 x 17 mA)/83 mA 0.2 0.6 0.56 13 0.56 13 X max X max DVR DVRO VR Change with High VRO VR(Vro e Vr) b VR(Vro e 6.3V) (5.06V between Anode and FEEDBACK) 2.5 2.8 7 10 7 10 mV max mV max DVR DV a VR Change with V a Change VR(V a e 5V) b VR(V a e 36V) (V a e 32V for LM614C) 0.1 0.1 1.2 1.3 1.2 1.3 mV max mV max 0.01 0.01 1 1.5 1 1.5 mV max mV max 35 40 50 55 nA max nA max VR(V a e 5V) b VR(V a e 3V) IFB FEEDBACK Bias Current VANODE s VFB s 5.06V 22 29 en Voltage Noise BW e 10 Hz to 10 kHz, VRO e VR 30 3 mVRMS http://www.national.com Electrical Characteristics (Continued) Note 1: Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the device beyond its rated operating conditions. Note 2: Input voltage above V a is allowed. Note 3: More accurately, it is excessive current flow, with resulting excess heating, that limits the voltages on all pins. When any pin is pulled a diode drop below Vb, a parasitic NPN transistor turns ON. No latch-up will occur as long as the current through that pin remains below the Maximum Rating. Operation is undefined and unpredictable when any parasitic diode or transistor is conducting. Note 4: Junction temperature may be calculated using TJ e TA a PDijA. The given thermal resistance is worst-case for packages in sockets in still air. For packages soldered to copper-clad board with dissipation from one comparator or reference output transistor, nominal ijA are 90§ C/W for the N package, WM package. Note 5: Human body model, 100 pF discharged through a 1.5 kX resistor. Note 6: Typical values in standard typeface are for TJ e 25§ C; values in boldface type apply for the full operating temperature range. These values represent the most likely parametric norm. Note 7: All limits are guaranteed at room temperature (standard type face) or at operating temperature extremes (bold type face). Note 8: Slew rate is measured with op amp in a voltage follower configuration. For rising slew rate, the input voltage is driven from 5V to 25V, and the output voltage transition is sampled at 10V and @ 20V. For falling slew rate, the input voltage is driven from 25V to 5V, and the output voltage transition is sampled at 20V and 10V. Note 9: VR is the Cathode-feedback voltage, nominally 1.244V. Note 10: Average reference drift is calculated from the measurement of the reference voltage at 25§ C and at the temperature extremes. The drift, in ppm/§ C, is 106 # DVR/(VR[25§ C] # DTJ), where DVR is the lowest value subtracted from the highest, VR[25§ C] is the value at 25§ C, and DTJ is the temperature range. This parameter is guaranteed by design and sample testing. Note 11: Hysteresis is the change in VR caused by a change in TJ, after the reference has been ‘‘dehysterized’’. To dehysterize the reference; that is minimize the hysteresis to the typical value, cycle its junction temperature in the following pattern, spiraling in toward 25§ C: 25§ C, 85§ C, b 40§ C, 70§ C, 0§ C, 25§ C. Note 12: Low contact resistance is required for accurate measurement. Note 13: A military RETSLM614AMX electrical test specification is available on request. The LM614AMJ/883 can also be procured as a Standard Military Drawing. Simplified Schematic Diagrams Op Amp TL/H/9326 – 2 Reference Bias TL/H/9326 – 3 http://www.national.com 4 Typical Performance Characteristics (Reference) TJ e 25§ C, FEEDBACK pin shorted to V b e 0V, unless otherwise noted Reference Voltage vs Temperature on 5 Representative Units Reference Voltage Drift Accelerated Reference Voltage Drift vs Time Reference Voltage vs Current and Temperature Reference Voltage vs Current and Temperature Reference Voltage vs Reference Current Reference Voltage vs Reference Current Reference AC Stability Range FEEDBACK Current vs FEEDBACK-to-Anode Voltage FEEDBACK Current vs FEEDBACK-to-Anode Voltage Reference Noise Voltage vs Frequency Reference Small-Signal Resistance vs Frequency TL/H/9326 – 4 5 http://www.national.com Typical Performance Characteristics (Reference) (Continued) TJ e 25§ C, FEEDBACK pin shorted to V b e 0V, unless otherwise noted Reference Power-Up Time Reference Voltage with FEEDBACK Voltage Step Reference Step Response for 100 mA E 10 mA Current Step Reference Voltage with 100 E 12 mA Current Step Reference Voltage Change with Supply Voltage Step TL/H/9326 – 8 Typical Performance Characteristics (Op Amps) Va e 5V, V b e GND e OV, V a a CM e V /2, VOUT e V /2, TJ e 25§ C, unless otherwise noted Input Common-Mode Voltage Range vs Temperature VOS vs Junction Temperature on 9 Representative Units Input Bias Current vs Common-Mode Voltage Slew Rate vs Temperature and Output Sink Current Large-Signal Step Response Output Voltage Swing vs Temp. and Current TL/H/9326 – 5 http://www.national.com 6 Typical Performance Characteristics (Op Amps) (Continued) V a e 5V, Vb e GND e 0V, VCM e V a /2, VOUT e V a /2, TJ e 25§ C, unless otherwise noted Output Source Current vs Output Voltage and Temp. Output Sink Current vs Output Voltage and Temp. Output Swing, Large Signal Output Impedance vs Frequency and Gain Small-Signal Pulse Response vs Temp. Small-Signal Pulse Response vs Load Op Amp Voltage Noise vs Frequency Op Amp Current Noise vs Frequency Small-Signal Voltage Gain vs Frequency and Temperature Small-Signal Voltage Gain vs Frequency and Load Follower Small-Signal Frequency Response Common-Mode Input Voltage Rejection Ratio TL/H/9326 – 6 7 http://www.national.com Typical Performance Characteristics (Op Amps) (Continued) V a e 5V, Vb e GND e 0V, VCM e V a /2, VOUT e V a /2, TJ e 25§ C, unless otherwise noted Power Supply Current vs Power Supply Voltage TL/H/9326 – 7 Positive Power Supply Voltage Rejection Ratio Negative Power Supply Voltage Rejection Ratio TL/H/9326–21 TL/H/9326 – 22 Input Offset Current vs Junction Temperature Input Bias Current vs Junction Temperature TL/H/9326–24 http://www.national.com TL/H/9326 – 38 8 Typical Performance Distributions Average VOS Drift Military Temperature Range Average VOS Drift Industrial Temperature Range TL/H/9326 – 29 TL/H/9326 – 30 Average VOS Drift Commercial Temperature Range Average IOS Drift Military Temperature Range TL/H/9326 – 31 TL/H/9326 – 32 Average IOS Drift Industrial Temperature Range Average IOS Drift Commercial Temperature Range TL/H/9326 – 34 TL/H/9326 – 33 9 http://www.national.com Typical Performance Distributions (Continued) Voltage Reference Broad-Band Noise Distribution Op Amp Voltage Noise Distribution TL/H/9326–35 Op Amp Current Noise Distribution TL/H/9326 – 36 TL/H/9326 – 37 Application Information VOLTAGE REFERENCE Reference Biasing The voltage reference is of a shunt regulator topology that models as a simple zener diode. With current Ir flowing in the ‘forward’ direction there is the familiar diode transfer function. Ir flowing in the reverse direction forces the reference voltage to be developed from cathode to anode. The cathode may swing from a diode drop below Vb to the reference voltage or to the avalanche voltage of the parallel protection diode, nominally 7V. A 6.3V reference with V a e 3V is allowed. TL/H/9326 – 10 FIGURE 2. Reference Equivalent Circuit TL/H/9326 – 11 FIGURE 3. 1.2V Reference TL/H/9326–9 FIGURE 1. Voltages Associated with Reference (Current Source Ir is External) The reference equivalent circuit reveals how Vr is held at the constant 1.2V by feedback, and how the FEEDBACK pin passes little current. To generate the required reverse current, typically a resistor is connected from a supply voltage higher than the reference voltage. Varying that voltage, and so varying Ir, has small effect with the equivalent series resistance of less than an ohm at the higher currents. Alternatively, an active current source, such as the LM134 series, may generate Ir. Capacitors in parallel with the reference are allowed. See the Reference AC Stability Range typical curve for capacitance valuesÐfrom 20 mA to 3 mA any capacitor value is stable. With the reference’s wide stability range with resistive and capacitive loads, a wide range of RC filter values will perform noise filtering. http://www.national.com Adjustable Reference The FEEDBACK pin allows the reference output voltage, Vro, to vary from 1.24V to 6.3V. The reference attempts to hold Vr at 1.24V. If Vr is above 1.24V, the reference will conduct current from Cathode to Anode; FEEDBACK current always remains low. If FEEDBACK is connected to Anode, then Vro e Vr e 1.24V. For higher voltages FEEDBACK is held at a constant voltage above AnodeÐsay 3.76V for Vro e 5V. Connecting a resistor across the constaint Vr generates a current I e R1/Vr flowing from Cathode into FEEDBACK node. A Thevenin equivalent 3.76V is generated from FEEDBACK to Anode with R2 e 3.76/I. Keep I 10 Application Information (Continued) greater than one thousand times larger than FEEDBACK bias current for k0.1% errorÐIt32 mA for the military grade over the military temperature range (I t5.5 mA for a 1% untrimmed error for a commercial part.) TL/H/9326 – 15 FIGURE 7. Output Voltage has Positive TC if R1 has Negative TC TL/H/9326 – 12 FIGURE 4. Thevenin Equivalent of Reference with 5V Output TL/H/9326 – 16 FIGURE 8. Diode in Series with R1 Causes Voltage across R1 and R2 to be Proportional to Absolute Temperature (PTAT) Connecting a resistor across Cathode-to-FEEDBACK creates a 0 TC current source, but a range of TCs may be synthesized. TL/H/9326 – 13 R1 e Vr/I e 1.24/32m e 39k R2 e R1 À(Vro/Vr) b 1Ó e 39k À(5/1.24) b 1)Ó e 118k FIGURE 5. Resistors R1 and R2 Program Reference Output Voltage to be 5V Understanding that Vr is fixed and that voltage sources, resistors, and capacitors may be tied to the FEEDBACK pin, a range of Vr temperature coefficients may be synthesized. TL/H/9326 – 17 I e Vr/R1 e 1.24/R1 TL/H/9326 – 14 FIGURE 9. Current Source is Programmed by R1 FIGURE 6. Output Voltage has Negative Temperature Coefficient (TC) if R2 has Negative TC 11 http://www.national.com Application Information (Continued) mon-mode range, another amp may be operated as a comparator, another with all terminals floating with no effect on the others (tying inverting input to output and non-inverting input to Vb on unused amps is preferred). Choosing operating points that cause oscillation, such as driving too large a capacitive load, is best avoided. Op Amp Output Stage These op amps, like their LM124 series, have flexible and relatively wide-swing output stages. There are simple rules to optimize output swing, reduce cross-over distortion, and optimize capacitive drive capability: 1) Output Swing: Unloaded, the 42 mA pull-down will bring the output within 300 mV of V b over the military temperature range. If more than 42 mA is required, a resistor from output to Vb will help. Swing across any load may be improved slightly if the load can be tied to V a , at the cost of poorer sinking open-loop voltage gain 2) Cross-over Distortion: The LM614 has lower cross-over distortion (a 1 VBE deadband versus 3 VBE for the LM124), and increased slew rate as shown in the characteristic curves. A resistor pull-up or pull-down will force class-A operation with only the PNP or NPN output transistor conducting, eliminating cross-over distortion 3) Capacitive Drive: Limited by the output pole caused by the output resistance driving capacitive loads, a pulldown resistor conducting 1 mA or more reduces the output stage NPN re until the output resistance is that of the current limit 25X. 200 pF may then be driven without oscillation. TL/H/9326–18 FIGURE 10. Proportional-to-Absolute-Temperature Current Source TL/H/9326–19 FIGURE 11. Negative-TC Current Source Hysteresis The reference voltage depends, slightly, on the thermal history of the die. Competitive micro-power products varyÐalways check the data sheet for any given device. Do not assume that no specification means no hysteresis. Op Amp Input Stage The lateral PNP input transistors, unlike most op amps, have BVEBO equal to the absolute maximum supply voltage. Also, they have no diode clamps to the positive supply nor across the inputs. These features make the inputs look like high impedances to input sources producing large differential and common-mode voltages. OPERATIONAL AMPLIFIERS Any amp or the reference may be biased in any way with no effect on the other amps or reference, except when a substrate diode conducts (see Guaranteed Electrical Characteristics Note 1). One amp input may be outside the com- http://www.national.com 12 Typical Applications VOUT e (R1 /Pe a 1) VREF R1, R2 should be 1% metal film Pb should be low T.C. trim pot TL/H/9326 – 42 FIGURE 12. Simple Low Quiescent Drain Voltage Regulator. Total supply current approximately 320 mA, when VIN e a 5V. TL/H/9326 – 44 FIGURE 14. Slow Rise Time Upon Power-Up, Adjustable Transducer Bridge Driver. Rise time is approximately 1 ms. TL/H/9326 – 43 *10k must be low t.c. trimpot. FIGURE 13. Ultra Low Noise 10.00V Reference. Total output noise is typically 14 mVRMS. TL/H/9326 – 46 FIGURE 16. Low Drop-Out Voltage Regulator Circuit, drop-out voltage is typically 0.2V. TL/H/9326 – 45 FIGURE 15. Transducer Data Acquisition System. Set zero code voltage, then adjust 10X gain adjust pot for full scale. 13 http://www.national.com Physical Dimensions inches (millimeters) unless otherwise noted Ceramic Dual-In-Line Package (J) Order Number LM614AMJ/883 NS Package Number J16A http://www.national.com 14 Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 16-Lead Molded Small Outline Package (WM) Order Number LM614CWM or LM614IWM NS Package Number M16B 15 http://www.national.com LM614 Quad Operational Amplifier and Adjustable Reference Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 16-Lead Molded Dual-In-Line Package (N) Order Number LM614CN, LM614AIN, LM614BIN, LM614AMN or LM614MN 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 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 1111 West Bardin Road Arlington, TX 76017 Tel: 1(800) 272-9959 Fax: 1(800) 737-7018 http://www.national.com 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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