LM611MN

LM611 Operational Amplifier and Adjustable Reference May 1998 LM611 Operational Amplifier and Adjustable Reference General Description The LM611 consists of a single-supply op-amp and a programmable voltage reference in one space saving 8-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 a wide output swing op-amp makes the LM611 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 Super-Block™ family, the LM611 is a space-saving monolithic alternative to a multi-chip solution, offering a high level of integration without sacrificing performance. Features OP AMP n Low operating current: 300 µA (op amp) 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 low cost 8-pin DIP 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 Reference floats above ground n Tolerant of load capacitance Applications n n n n Transducer bridge driver Process and Mass Flow Control systems Power supply voltage monitor Buffered voltage references for A/D’s Connection Diagrams DS009221-1 DS009221-2 Super-Block™ is a trademark of National Semiconductor Corporation. © 1999 National Semiconductor Corporation DS009221 www.national.com Absolute Maximum Ratings (Note 1) 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) Current through Any Input Pin and VR Pin Differential Input Voltage Military and Industrial Commercial Storage Temperature Range Maximum Junction Temperature 36V (Max) −0.3V (Min) Thermal Resistance, Junction-to-Ambient (Note 3) N Package 100˚C/W M Package 150˚C/W Soldering Information Soldering (10 seconds) N Package 260˚C M Package 220˚C ± 1 kV ESD Tolerance (Note 4) ± 20 mA ± 36V ± 32V −65˚C≤TJ≤+150˚C 150˚C Operating Temperature Range LM611AI, LM611I, LM611BI LM611AM, LM611M LM611C −40˚C≤TJ≤+85˚C −55˚C≤TJ≤+125˚C 0˚C≤TJ≤70˚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. LM611M LM611AM Symbol Parameter Conditions Typical (Note 5) LM611AI Limits (Note 6) IS VS Total Supply Current Supply Voltage Range RLOAD = ∞, 4V ≤ V+ ≤ 36V (32V for LM611C) 210 221 2.2 2.9 46 43 OPERATIONAL AMPLIFIER VOS1 VOS2 VOS Over Supply VOS Over VCM Average VOS Drift IB IOS Input Bias Current Input Offset Current Average Offset Drift Current RIN CIN en In CMRR Input Resistance Input Capacitance Voltage Noise Current Noise Common-Mode Rejection-Ratio Differential Common-Mode Common-Mode f = 100 Hz, Input Referred f = 100 Hz, Input Referred V+ = 30V, 0V ≤ VCM ≤ (V+ − 1.8V) CMRR = 20 log (∆VCM/∆VOS) 4V ≤ V+ ≤ 36V (4V ≤ V+ ≤ 32V for LM611C) VCM = 0V through VCM = (V+ − 1.8V), V+ = 30V, V− = 0V (Note 6) 1.5 2.0 1.0 1.5 15 10 11 0.2 0.3 4 1800 3800 5.7 74 58 95 90 80 75 75 70 dB min dB min 25 30 4 5 35 40 4 5 3.5 6.0 3.5 6.0 5.0 7.0 5.0 7.0 mV max mV max mV max mV max µV/˚C max nA max nA max nA max nA max pA/˚C MΩ MΩ pF 300 320 2.8 3 36 36 LM611BI LM611I LM611C Limits (Note 6) 350 370 2.8 3 32 32 µA max µA max V min V min V max V max Units www.national.com 2 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. LM611M LM611AM Symbol Parameter Conditions Typical (Note 5) LM611AI Limits (Note 6) OPERATIONAL AMPLIFIER PSRR AV SR GBW VO1 VO2 IOUT ISINK ISHORT Power Supply Rejection-Ratio Open Loop Voltage Gain Slew Rate Gain Bandwidth Output Voltage Swing High Output Voltage Swing Low Output Source Current Output Sink Current Short Circuit Current 4V ≤ V+ ≤ 30V, VCM = V+/2, PSRR = 20 log (∆V+/∆VOS) RL = 10 kΩ to GND, V+ = 30V, 5V ≤ VOUT ≤ 25V V+ = 30V (Note 7) CL = 50 pF RL = 10 kΩ to GND V+ = 36V (32V for LM611C) RL = 10 kΩ to V+ V+ = 36V (32V for LM611C) VOUT = 2.5V, V+IN = 0V, V−IN = −0.3V VOUT = 1.6V, V+IN = 0V, V−IN = 0.3V VOUT = 0V, V+IN = 3V, V−IN = 2V, Source VOUT = 5V, V+IN = 2V, V−IN = 3V, Sink VOLTAGE REFERENCE VR Reference Voltage (Note 8) 1.244 1.2365 1.2515 ( ± 0.6%) Average Temperature Drift Hysteresis (Note 9) 10 Hyst = (Vro' − Vro)/∆TJ (Note 10) VR(100 µA) − VR(17 µA) VR(10 mA) − VR(100 µA) (Note 11) R Resistance VR Change with High VRO VR Change with V+ Change ∆VR(10→0.1 mA)/9.9 mA ∆VR(100→17 µA)/83 µA VR(Vro = Vr) LM611BI LM611I LM611C Limits (Note 6) Units 110 100 500 50 0.70 0.65 0.80 0.50 V+ − 1.4 V+ − 1.6 V− + 0.8 V + 0.9 25 15 17 9 30 40 30 32 − 80 75 100 40 0.55 0.45 75 70 94 40 0.50 0.45 dB min dB min V/mV min V/µs MHz V+ − 1.7 V+ − 1.9 V− + 0.9 V + 1.0 20 13 14 8 50 60 60 80 − V+ − 1.8 V+ − 1.9 V− + 0.95 V− + 1.0 16 13 13 8 50 60 70 90 1.2191 1.2689 ( ± 2.0%) 150 V min V min V max V max mA min mA min mA min mA min mA max mA max mA max mA max V min V max PPM/˚C max µV/˚C 80 3.2 0.05 0.1 1.5 2.0 0.2 0.6 2.5 2.8 0.1 0.1 0.01 0.01 1 1.1 5 5.5 0.56 13 7 10 1.2 1.3 1 1.5 1 1.1 5 5.5 0.56 13 7 10 1.2 1.3 1 1.5 VR Change with Current mV max mV max mV max mV max Ω max Ω max mV max mV max mV max mV max mV max mV max www.national.com − VR(Vro = 6.3V) (5.06V between Anode and FEEDBACK) VR(V+ = 5V) − VR(V+ = 36V) (V+ = 32V for LM611C) VR(V+ = 5V) − VR(V+ = 3V) 3 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. LM611M LM611AM Symbol Parameter Conditions Typical (Note 5) LM611AI Limits (Note 6) VOLTAGE REFERENCE VR Change with VANODE Change IFB en FEEDBACK Bias Current VR Noise 10 Hz to 10,000 Hz, VRO = VR V+ = V+ max, ∆VR = VR (@ VANODE = V− = GND) − VR ( @ VANODE = V+ − 1.0V) IFB; VANODE ≤ VFB ≤ 5.06V 0.7 3.3 22 29 30 1.5 3.0 35 40 1.6 3.0 50 55 mV max mV max nA max nA max µVRMS LM611BI LM611I LM611C Limits (Note 6) Units 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: 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 3: Junction temperature may be calculated using TJ = TA + PD θJA. 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 op amp or reference output transistor, nominal θJA is 90˚C/W for the N package and 135˚C/W for the M package. Note 4: Human body model, 100 pF discharged through a 1.5 kΩ resistor. Note 5: 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 6: All limits are guaranteed at room temperature (standard type face) or at operating temperature extremes (bold face type). Note 7: 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 output voltage transition is sampled at 20V and 10V. Note 8: VR is the cathode-feedback voltage, nominally 1.244V. Note 9: 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 10: 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, its junction temperature should be cycled in the following pattern, spiraling in toward 25˚C: 25˚C, 85˚C, −40˚C, 70˚C, 0˚C, 25˚C. Note 11: Low contact resistance is required for accurate measurement. Note 12: Military RETS 611AMX electrical test specification is available on request. The LM611AMJ/883 can also be procured as a Standard Military Drawing. Simplified Schematic Diagrams Op Amp DS009221-3 www.national.com 4 Simplified Schematic Diagrams Reference (Continued) Bias DS009221-91 DS009221-92 Typical Performance Characteristics (Reference) 0V, unless otherwise noted Reference Voltage vs Temp on 5 Representative Units Reference Voltage Drift TJ = 25˚C, FEEDBACK pin shorted to V− = Accelerated Reference Voltage Drift vs Time DS009221-34 DS009221-33 DS009221-35 Reference Voltage vs Current and Temperature Reference Voltage vs Current and Temperature Reference Voltage vs Reference Current DS009221-36 DS009221-37 DS009221-38 5 www.national.com Typical Performance Characteristics (Reference) = 0V, unless otherwise noted (Continued) Reference Voltage vs Reference Current Reference AC Stability Range TJ = 25˚C, FEEDBACK pin shorted to V− Feedback Current vs Feedback-to-Anode Voltage DS009221-39 DS009221-40 DS009221-41 Feedback Current vs Feedback-to-Anode Voltage Reference Noise Voltage vs Frequency Reference Small-Signal Resistance vs Frequency DS009221-42 DS009221-43 DS009221-44 Reference Power-Up Time Reference Voltage with Feedback Voltage Step Reference Voltage with 100z12 µA Current Step DS009221-45 DS009221-46 DS009221-47 www.national.com 6 Typical Performance Characteristics (Reference) = 0V, unless otherwise noted (Continued) Reference Step Response for 100 µA z 10 mA Current Step TJ = 25˚C, FEEDBACK pin shorted to V− Reference Voltage Change with Supply Voltage Step DS009221-49 DS009221-48 Typical Performance Characteristics (Op Amps) = V+/2, TJ = 25˚C, unless otherwise noted Input Common-Mode Voltage Range vs Temperature VOS vs Junction Temperature V+ = 5V, V− = GND = 0V, VCM = V+/2, VOUT Input Bias Current vs Common-Mode Voltage DS009221-50 DS009221-51 DS009221-52 Reference Change vs Common-Mode Voltage Large-Signal Step Response Output Voltage Swing vs Temp. and Current DS009221-53 DS009221-54 DS009221-55 7 www.national.com Typical Performance Characteristics (Op Amps) VOUT = V+/2, TJ = 25˚C, unless otherwise noted (Continued) Output Source Current vs Output Voltage and Temp. V+ = 5V, V− = GND = 0V, VCM = V+/2, Output Sink Current vs Output Voltage Output Swing, Large Signal DS009221-56 DS009221-57 DS009221-58 Output Impedance vs Frequency and Gain Small Signal Pulse Response vs Temp. Small-Signal Pulse Response vs Load DS009221-59 DS009221-60 DS009221-61 Op Amp Voltage Noise vs Frequency Op Amp Current Noise vs Frequency Small-Signal Voltage Gain vs Frequency and Temperature DS009221-62 DS009221-63 DS009221-64 www.national.com 8 Typical Performance Characteristics (Op Amps) VOUT = V+/2, TJ = 25˚C, unless otherwise noted (Continued) Small-Signal Voltage Gain vs Frequency and Load Follower Small-Signal Frequency Response V+ = 5V, V− = GND = 0V, VCM = V+/2, Common-Mode Input Voltage Rejection Ratio DS009221-65 DS009221-66 DS009221-67 Power Supply Current vs Power Supply Voltage Positive Power Supply Voltage Rejection Ratio Negative Power Supply Voltage Rejection Ratio DS009221-68 DS009221-69 DS009221-70 Slew Rate vs Temperature Input Offset Current vs Junction Temperature Input Bias Current vs Junction Temperature DS009221-71 DS009221-72 DS009221-73 9 www.national.com Typical Performance Distributions Average VOS Drift Military Temperature Range Average VOS Drift Industrial Temperature Range Average VOS Drift Commercial Temperature Range DS009221-74 DS009221-75 DS009221-76 Average IOS Drift Military Temperature Range Average IOS Drift Industrial Temperature Range Average IOS Drift Commercial Temperature Range DS009221-77 DS009221-78 DS009221-79 Voltage Reference Broad-Band Noise Distribution Op Amp Voltage Noise Distribution Op Amp Current Noise Distribution DS009221-80 DS009221-81 DS009221-82 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 applied voltage to the cathode may range 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. DS009221-14 FIGURE 1. Voltages Associated with Reference (Current Source Ir is External) 10 www.national.com Application Information (Continued) 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. DS009221-17 FIGURE 4. Thevenin Equivalent of Reference with 5V Output DS009221-15 FIGURE 2. Reference Equivalent Circuit DS009221-18 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 DS009221-16 FIGURE 3. 1.2V Reference Capacitors in parallel with the reference are allowed. See the Reference AC Stability Range 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. 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 = R1/Vr 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.) 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. DS009221-19 FIGURE 6. Output Voltage has Negative Temperature Coefficient (TC) if R2 has Negative TC DS009221-20 FIGURE 7. Output Voltage has Positive TC if R1 has Negative TC 11 www.national.com Application Information (Continued) DS009221-24 FIGURE 11. Negative −TC Current Source DS009221-21 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. 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 AMPLIFIER The amp or the reference may be biased in any way with no effect on the other, except when a substrate diode conducts (see Guaranteed Electrical Characteristics Note 1). The amp may have inputs outside the common-mode range, may be operated as a comparator, or have all terminals floating with no effect on the reference (tying inverting input to output and non-inverting input to V− on unused amp is preferred). Choosing operating points that cause oscillation, such as driving too large a capacitive load, is best avoided. Op Amp Output Stage The op amp, like the LM124 series, has a flexible and relatively wide-swing output stage. 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. 2. Cross-over Distortion: The LM611 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 pull-down resistor conducting 1 mA or more reduces the output stage NPN re until the output resistance is that of the current limit 25Ω. 200 pF may then be driven without oscillation. Op Amp Input Stage The lateral PNP input transistors, unlike those of 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. DS009221-22 I = Vr/R1 = 1.24/R1 FIGURE 9. Current Source is Programmed by R1 DS009221-23 FIGURE 10. Proportional-to-AbsoluteTemperature Current Source www.national.com 12 Typical Applications DS009221-28 *10k must be low t.c. trim pot. DS009221-30 FIGURE 12. Ultra Low Noise 10.00V Reference. Total Output Noise is Typically 14 µVRMS. Adjust the 10k pot for 10.000V. FIGURE 13. Simple Low Quiescent Drain Voltage Regulator. Total Supply Current is approximately 320 µA when VIN = 5V, and output has no load. DS009221-29 VOUT = (R1/R2 + 1) VREF. R1, R2 should be 1% metal film. R3 should be low t.c. trim pot. FIGURE 14. Slow Rise-Time Upon Power-Up, Adjustable Transducer Bridge Driver. Rise-time is approximately 0.5 ms. DS009221-31 FIGURE 15. Low Drop-Out Voltage Regulator Circuit. Drop out voltage is typically 0.2V. 13 www.national.com Typical Applications (Continued) DS009221-32 FIGURE 16. Nulling Bridge Detection System. Adjust sensitivity via 400 kΩ pot. Null offset with R1, and bridge drive with the 10k pot. www.national.com 14 Ordering Information Reference Tolerance & VOS Temperature Range Military −55˚C≤TA≤+125˚C LM611AMN LM611AMJ/883 (Note 12) LM611MN — Industrial −40˚C≤TA≤+85˚C LM611AIN — LM611BIN LM611IM Commercial 0˚C≤TA≤+70˚C — — LM611CN LM611CM 8-pin molded DIP 8-pin ceramic DIP 8-pin molded DIP 14-pin Narrow Surface Mount M14A J08A N08E N08E Package NSC Drawing ± 0.6% @ 80 ppm/˚C max VOS = 3.5 mV max ± 2.0% @ 150 ppm/˚C max VOS = 5 mV max 15 www.national.com Physical Dimensions inches (millimeters) unless otherwise noted Hermetic Dual-In-Line Package (J) Order Number LM611AMJ/883 NS Package Number J08A Plastic Surface Mount Narrow Package (0.15) (M) Order Number LM611CM or LM611IM NS Package Number M14A www.national.com 16 LM611 Operational Amplifier and Adjustable Reference Physical Dimensions inches (millimeters) unless otherwise noted (Continued) Plastic Dual-In-Line Package (N) Order Number LM611CN, LM611AIN, LM611BIN, LM611AMN or LM611MN NS Package Number N08E 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: support@nsc.com www.national.com National Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: europe.support@nsc.com 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. National Semiconductor Asia Pacific Customer Response Group Tel: 65-2544466 Fax: 65-2504466 Email: sea.support@nsc.com National Semiconductor Japan Ltd. Tel: 81-3-5639-7560 Fax: 81-3-5639-7507 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.