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 (1Ω 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™ family, the LM614 is a space-saving monolithic alternative to a multichip solution, offering a high level of integration without sacrificing performance. Op Amp n Low operating current: 300 µA n Wide supply voltage range: 4V to 36V n Wide common-mode range: V− to (V+− 1.8V) n Wide differential input voltage: ± 36V n Available in plastic package rated for Military Temperature Range Operation Reference n Adjustable output voltage: 1.2V to 6.3V n Tight initial tolerance available: ± 0.6% n Wide operating current range: 17 µA to 20 mA n Tolerant of load capacitance Applications n n n n 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 DS009326-1 Ordering Information Reference Tolerance & VOS ± 0.6%@ Temperature Range Military Industrial Commercial −55˚C ≤ TA ≤ +125˚C −40˚C ≤ TA ≤ +85˚C 0˚C ≤ TA ≤ +70˚C LM614AMN LM614AIN — 80 ppm/˚C max VOS ≤ 3.5 mV max LM614AMJ/883 — — 16-pin N16E 16-pin J16A Ceramic DIP LM614MN LM614BIN LM614CN 150 ppm/˚C max VOS ≤ 5.0 mV NSC Drawing Molded DIP (Note 13) ± 2.0%@ Package 16-pin N16E Molded DIP — LM614WM LM614CWM 16-pin Wide M16B Surface Mount Super-Block™ is a trademark of National Semiconductor Corporation. © 1999 National Semiconductor Corporation DS009326 www.national.com LM614 Quad Operational Amplifier and Adjustable Reference May 1998 Absolute Maximum Ratings (Note 1) 36V (Max) −0.3V (Min) Maximum Junction Temperature Thermal Resistance, Junction-to-Ambient (Note 4) N Package WM Package Soldering Information (Soldering, 10 seconds) N Package WM Package ESD Tolerance (Note 5) ± 20 mA Operating Temperature Range 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 V− pin) (Note 2) (Note 3) Current through Any Input Pin & VR Pin Differential Input Voltage Military and Industrial Commercial Storage Temperature Range 260˚C 220˚C ± 1kV −55˚C ≤ TJ ≤ +125˚C LM614AM, LM614M 0˚C ≤ TJ ≤ +70˚C LM614C −65˚C ≤ TJ ≤ +150˚C 100˚C 150˚C −40˚C ≤ TJ ≤ +85˚C LM614AI, LM614I, LM614BI ± 36V ± 32V 150˚C Electrical Characteristics These specifications apply for V− = GND = 0V, V+ = 5V, VCM = VOUT = 2.5V, IR = 100 µA, FEEDBACK pin shorted to GND, unless otherwise specified. Limits in standard typeface are for TJ = 25˚C; limits in boldface type apply over the Operating Temperature Range . Symbol Parameter Conditions Typical (Note 6) LM614AM LM614M LM614AI LM614BI Limits LM614I (Note 7) LM614C Units Limits (Note 7) IS VS Total Supply RLOAD = ∞, 450 940 1000 µA max Current 4V ≤ V+ ≤ 36V (32V for LM614C) 550 1000 1070 µA max 2.2 2.8 2.8 V min 2.9 3 3 V min 46 36 32 V max 43 36 32 V max Supply Voltage Range OPERATIONAL AMPLIFIER VOS1 VOS2 VOS Over Supply 4V ≤ V+ ≤ 36V 1.5 3.5 5.0 mV max 2.0 6.0 7.0 mV max VOS Over VCM (4V ≤ V+ ≤ 32V for LM614C) VCM = 0V through VCM = 1.0 3.5 5.0 mV max (V+ − 1.8V), V+ = 30V 1.5 6.0 7.0 mV max (Note 7) 15 Average VOS Drift µV/˚C max IB Input Bias Current 10 25 35 nA max 11 30 40 nA max IOS Input Offset Current 0.2 4 4 nA max 0.3 5 5 nA max Average Offset Drift Current RIN Input Resistance 4 pA/˚C Differential 1800 MΩ Common-Mode 3800 MΩ 5.7 pF CIN Input Capacitance en Voltage Noise Common-Mode Input f = 100 Hz, Input Referred In Current Noise f = 100 Hz, Input Referred 58 Common-Mode V+ = 30V, 0V ≤ VCM ≤ (V+ − 1.8V), CMRR = 20 log (∆VCM/∆VOS) 95 80 75 dB min 90 75 70 dB min CMRR Rejection Ratio www.national.com 2 74 Electrical Characteristics (Continued) These specifications apply for V− = GND = 0V, V+ = 5V, VCM = VOUT = 2.5V, IR = 100 µA, FEEDBACK pin shorted to GND, unless otherwise specified. Limits in standard typeface are for TJ = 25˚C; limits in boldface type apply over the Operating Temperature Range . Symbol Parameter Conditions Typical (Note 6) LM614AM LM614M LM614AI LM614BI Limits LM614I (Note 7) LM614C Units Limits (Note 7) OPERATIONAL AMPLIFIER PSRR Power Supply Rejection Ratio AV Open Loop 4V ≤ V+ ≤ 30V, VCM = V+/2, PSRR = 20 log (∆V+/∆VOS) RL = 10 kΩ to GND, V+ = 30V, 110 80 75 dB min 100 75 70 dB min 500 100 94 V/mV 50 40 40 min ± 0.70 ± 0.65 ± 0.55 ± 0.45 ± 0.50 ± 0.45 V/µs SR Slew Rate 5V ≤ VOUT ≤ 25V V+ = 30V (Note 8) GBW Gain Bandwidth CL = 50 pF Voltage Gain 0.8 MHz 0.52 VO1 Output Voltage Swing High VO2 Output Voltage Swing Low IOUT Output Source ISINK Output Sink Current ISHORT Short Circuit Current RL = 10 kΩ to GND V+ = 36V (32V for LM614C) RL = 10 kΩ to V+ V+ = 36V (32V for LM614C) VOUT = 2.5V, V+IN = 0V, V−IN = −0.3V VOUT = 1.6V, V+IN = 0V, V−IN = 0.3V MHz V+ − 1.4 V+ − 1.7 V+ − 1.8 V min V+ − 1.6 V+ − 1.9 V+ − 1.9 V min V− + 0.8 V− + 0.9 V− + 0.95 V max V− + 0.9 V− + 1.0 V− + 1.0 V max 25 20 16 mA min 15 13 13 mA min 17 14 13 mA min 9 8 8 mA min VOUT = 0V, V+IN = 3V, V−IN = 2V, Source 30 50 50 mA max 40 60 60 mA max VOUT = 5V, V+IN = 2V, V−IN = 3V, Sink 30 60 70 mA max 32 80 90 mA max 1.244 1.2365 1.2191 V min 1.2515 1.2689 V max ( ± 0.6%) ( ± 2.0%) 80 150 VOLTAGE REFERENCE VR Voltage Reference Average Temperature (Note 9) (Note 10) 10 Drift Hysteresis max (Note 11) 3.2 VR Change VR(100 µA) − VR(17 µA) µV/˚C 0.05 1 1 0.1 1.1 1.1 mV max VR(10 mA) − VR(100 µA) 1.5 5 5 mV max (Note 12) 2.0 5.5 5.5 mV max ∆VR(10→0.1 mA)/9.9 mA 0.2 0.56 0.56 Ω max ∆VR(100→17 µA)/83 µA 0.6 13 13 Ω max VR Change VR(Vro 2.5 7 7 mV max with High VRO (5.06V between Anode and 2.8 10 10 mV max with Current R PPM/˚C Resistance = Vr) − VR(Vro = 6.3V) mV max FEEDBACK) 3 www.national.com Electrical Characteristics (Continued) These specifications apply for V− = GND = 0V, V+ = 5V, VCM = VOUT = 2.5V, IR = 100 µA, FEEDBACK pin shorted to GND, unless otherwise specified. Limits in standard typeface are for TJ = 25˚C; limits in boldface type apply over the Operating Temperature Range . Symbol Parameter Conditions Typical (Note 6) LM614AM LM614M LM614AI LM614BI Limits LM614I (Note 7) LM614C Units Limits (Note 7) VOLTAGE REFERENCE VR Change with V+ Change IFB FEEDBACK Bias VR(V + = 5V) − VR(V + = 36V) (V+ = 32V for LM614C) 0.1 1.2 1.2 0.1 1.3 1.3 mV max VR(V + 0.01 1 1 mV max 0.01 1.5 1.5 mV max 22 35 50 nA max 29 40 55 nA max = 5V) − VR(V + = 3V) VANODE ≤ VFB ≤ 5.06V Current en Voltage Noise BW = 10 Hz to 10 kHz, VRO = VR 30 mV max µVRMS 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+ 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 V−, 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 = TA + PDθjA. 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 θjA are 90˚C/W for the N package, WM package. Note 5: Human body model, 100 pF discharged through a 1.5 kΩ resistor. Note 6: Typical values in standard typeface are for TJ = 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 • ∆VR/(VR[25˚C] • ∆TJ), where ∆VR is the lowest value subtracted from the highest, VR[25˚C] is the value at 25˚C, and ∆TJ 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, −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 DS009326-2 www.national.com 4 Simplified Schematic Diagrams (Continued) Reference / Bias DS009326-3 Typical Performance Characteristics (Reference) TJ = 25˚C, FEEDBACK pin shorted to V− = 0V, unless otherwise noted Reference Voltage vs Temperature on 5 Representative Units Accelerated Reference Voltage Drift vs Time Reference Voltage Drift DS009326-48 DS009326-49 DS009326-47 Reference Voltage vs Current and Temperature Reference Voltage vs Current and Temperature DS009326-50 Reference Voltage vs Reference Current DS009326-51 5 DS009326-52 www.national.com Typical Performance Characteristics (Reference) TJ = 25˚C, FEEDBACK pin shorted to V− = 0V, unless otherwise noted (Continued) Reference Voltage vs Reference Current Reference AC Stability Range FEEDBACK Current vs FEEDBACK-to-Anode Voltage DS009326-53 DS009326-54 DS009326-55 FEEDBACK Current vs FEEDBACK-to-Anode Voltage Reference Noise Voltage vs Frequency Reference Small-Signal Resistance vs Frequency DS009326-57 DS009326-58 DS009326-56 Reference Power-Up Time Reference Voltage with FEEDBACK Voltage Step Reference Voltage with 100z12 µA Current Step DS009326-59 DS009326-60 www.national.com 6 DS009326-61 Typical Performance Characteristics (Reference) TJ = 25˚C, FEEDBACK pin shorted to V− = 0V, unless otherwise noted (Continued) Reference Step Response for 100 µA z 10 mA Current Step Reference Voltage Change with Supply Voltage Step DS009326-63 DS009326-62 Typical Performance Characteristics (Op Amps) V+ = 5V, V− = GND = 0V, VCM = V+/2, VOUT = V+/2, TJ = 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 DS009326-66 DS009326-64 Slew Rate vs Temperature and Output Sink Current DS009326-65 Large-Signal Step Response Output Voltage Swing vs Temp. and Current DS009326-67 DS009326-68 7 DS009326-69 www.national.com Typical Performance Characteristics (Op Amps) V+ = 5V, V− = GND = 0V, VCM = V+/2, VOUT = V+/2, TJ = 25˚C, unless otherwise noted (Continued) Output Source Current vs Output Voltage and Temp. Output Sink Current vs Output Voltage and Temp. DS009326-71 DS009326-70 Output Impedance vs Frequency and Gain Output Swing, Large Signal Small-Signal Pulse Response vs Temp. Small-Signal Pulse Response vs Load DS009326-74 DS009326-73 Op Amp Voltage Noise vs Frequency DS009326-72 Op Amp Current Noise vs Frequency DS009326-76 DS009326-75 Small-Signal Voltage Gain vs Frequency and Temperature DS009326-77 DS009326-78 www.national.com 8 Typical Performance Characteristics (Op Amps) V+ = 5V, V− = GND = 0V, VCM = V+/2, VOUT = V+/2, TJ = 25˚C, unless otherwise noted (Continued) Small-Signal Voltage Gain vs Frequency and Load Follower Small-Signal Frequency Response DS009326-79 Common-Mode Input Voltage Rejection Ratio DS009326-81 DS009326-80 Power Supply Current vs Power Supply Voltage DS009326-7 Positive Power Supply Voltage Rejection Ratio Negative Power Supply Voltage Rejection Ratio DS009326-21 DS009326-22 9 www.national.com Typical Performance Characteristics (Op Amps) V+ = 5V, V− = GND = 0V, VCM = V+/2, VOUT = V+/2, TJ = 25˚C, unless otherwise noted (Continued) Input Offset Current vs Junction Temperature Input Bias Current vs Junction Temperature DS009326-24 DS009326-38 Typical Performance Distributions Average VOS Drift Military Temperature Range Average VOS Drift Industrial Temperature Range DS009326-29 Average VOS Drift Commercial Temperature Range DS009326-30 Average IOS Drift Military Temperature Range DS009326-31 www.national.com DS009326-32 10 Typical Performance Distributions Average IOS Drift Industrial Temperature Range (Continued) Average IOS Drift Commercial Temperature Range DS009326-34 DS009326-33 Voltage Reference Broad-Band Noise Distribution Op Amp Voltage Noise Distribution DS009326-35 Op Amp Current Noise Distribution DS009326-36 11 DS009326-37 www.national.com 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 V− to the reference voltage or to the avalanche voltage of the parallel protection diode, nominally 7V. A 6.3V reference with V+ = 3V is allowed. DS009326-11 FIGURE 3. 1.2V Reference 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 = Vr = 1.24V. For higher voltages FEEDBACK is held at a constant voltage above Anode — say 3.76V for Vro = 5V. Connecting a resistor across the constant Vr generates a current I = Vr/R1 flowing from Cathode into FEEDBACK node. A Thevenin equivalent 3.76V is generated from FEEDBACK to Anode with R2 = 3.76/I. Keep I greater than one thousand times larger than FEEDBACK bias current for < 0.1% error — I≥32 µA for the military grade over the military temperature range (I≥5.5 µA for a 1% untrimmed error for a commercial part.) DS009326-9 FIGURE 1. Voltages Associated with Reference (Current Source Ir is External) The reference equivalent circuit reveals how Vris 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 values — from 20 µA 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. DS009326-12 FIGURE 4. Thevenin Equivalent of Reference with 5V Output DS009326-10 DS009326-13 FIGURE 2. Reference Equivalent Circuit R1 = Vr/I = 1.24/32µ = 39k R2 = R1 {(Vro/Vr) − 1} = 39k {(5/1.24) − 1)} = 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. www.national.com 12 Application Information (Continued) DS009326-18 DS009326-14 FIGURE 10. Proportional-to-Absolute-Temperature Current Source FIGURE 6. Output Voltage has Negative Temperature Coefficient (TC) if R2 has Negative TC DS009326-15 DS009326-19 FIGURE 7. Output Voltage has Positive TC if R1 has Negative TC FIGURE 11. Negative-TC Current Source Hysteresis The reference voltage depends, slightly, on the thermal history of the die. Competitive micro-power products vary — always check the data sheet for any given device. Do not assume that no specification means no hysteresis. 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 common-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 V− on unused amps is preferred). Choosing operating points that cause oscillation, such as driving too large a capacitive load, is best avoided. DS009326-16 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. 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 µA pull-down will bring the output within 300 mV of V− over the military temperature range. If more than 42 µA is required, a resistor from output to V− will help. Swing across any load may be improved slightly if the load can be tied to V+, at the cost of poorer sinking open-loop voltage gain DS009326-17 I = Vr/R1 = 1.24/R1 FIGURE 9. Current Source is Programmed by R1 13 www.national.com Application Information 2. 3. output stage NPN re until the output resistance is that of the current limit 25Ω. 200 pF may then be driven without oscillation. (Continued) 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 Capacitive Drive: Limited by the output pole caused by the output resistance driving capacitive loads, a pull-down resistor conducting 1 mA or more reduces the 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. Typical Applications DS009326-44 DS009326-42 VOUT = (R1 /Pe + 1) VREF R1, R2 should be 1% metal film Pβ should be low T.C. trim pot FIGURE 12. Simple Low Quiescent Drain Voltage Regulator. Total supply current approximately 320 µA, when VIN = +5V. FIGURE 14. Slow Rise Time Upon Power-Up, Adjustable Transducer Bridge Driver. Rise time is approximately 1 ms. DS009326-43 *10k must be low t.c. trimpot. FIGURE 13. Ultra Low Noise 10.00V Reference. Total output noise is typically 14 µVRMS. DS009326-46 FIGURE 15. Low Drop-Out Voltage Regulator Circuit, drop-out voltage is typically 0.2V. www.national.com 14 Typical Applications (Continued) DS009326-45 FIGURE 16. Transducer Data Acquisition System. Set zero code voltage, then adjust 10Ω gain adjust pot for full scale. 15 www.national.com Physical Dimensions inches (millimeters) unless otherwise noted Ceramic Dual-In-Line Package (J) Order Number LM614AMJ/883 NS Package Number J16A 16-Lead Molded Small Outline Package (WM) Order Number LM614CWM or LM614IWM NS Package Number M16B www.national.com 16 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 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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