Datasheet LM614CN, LM614AIN Datasheet (NSC)

December 2001

LM614
Quad Operational Amplifier and Adjustable Reference

LM614 Quad Operational Amplifier and Adjustable Reference

General Description

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), initial tolerance
(2.0%), and the ability to be programmed from 1.2V to 5.0V
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
LM614 is a space-saving monolithic alternative to a multichip
solution, offering a high level of integration without sacrificing
performance.

™

family, the

Connection Diagram

Features

Op Amp

n Low operating current: 450µA
n Wide supply voltage range: 4V to 36V
n Wide common-mode range: V
n Wide differential input voltage:

Reference

n Adjustable output voltage: 1.2V to 5.0V
n Initial tolerance:
n Wide operating current range: 17µA to 20mA
n Tolerant of load capacitance

±

2.0%

−

to (V+− 1.8V)

±

36V

Applications

n Transducer bridge driver and signal processing
n Process and mass flow control systems
n Power supply voltage monitor
n Buffered voltage references for A/D’s

00932601

Ordering Information

Temperature

Package

16-Pin Wide
Body SOIC

Super-Block™is a trademark of National Semiconductor Corporation.

© 2001 National Semiconductor Corporation DS009326 www.national.com

Range Part Number Package Marking Transport Media NSC Drawing

0˚C to 70˚C LM614CWM LM614CWM Rails M16B

LM614CWMX LM614CWM 1k Units Tape and Reel

−40˚C to 85˚C LM614IWM LM614IWM Rails
LM614IWMX LM614IWM 1k Units Tape and Reel

Absolute Maximum Ratings (Note 1)

LM614

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

Voltage on Any Pins except V

R

(referred to V−pin)
(Note 2) 36V (Max)
(Note 3) −0.3V (Min)

Current through Any Input Pin &

V

Pin

R

±

20 mA

Differential Input Voltage

LM614I
LM614C

Electrical Characteristics

These specifications apply for V−= GND = 0V, V+= 5V, VCM=V
unless otherwise specified. Limits in standard typeface are for T

Temperature Range .

Symbol Parameter Conditions Typ

I

S

V

S

OPERATIONAL AMPLIFIER

V

OS1

V

OS2

I

B

I

OS

Total Supply R

LOAD

Current 4V ≤ V
Supply Voltage Range 2.2 2.8 V min

VOSOver Supply 4V ≤ V+≤ 36V 1.5 5.0 mV max

(4V ≤ V

VOSOver V

CM

VCM= 0V through VCM= 1.0 5.0 mV max

+

(V

− 1.8V), V+= 30V 1.5 7.0 mV max

Average VOSDrift (Note 7)

Input Bias Current 10 35 nA max

Input Offset Current 0.2 4 nA max

Average Offset
Drift Current

Storage Temperature Range −65˚C ≤ T

≤ +150˚C

J

Maximum Junction Temperature 150˚C
Thermal Resistance,

Junction-to-Ambient (Note 4) 150˚C
Soldering Information (Soldering,

10 sec.) 220˚C
ESD Tolerance (Note 5)

±

1kV

Operating Temperature Range

LM614I −40˚C ≤ TJ≤ +85˚C

±
±

36V
32V

LM614C 0˚C ≤ T

= 2.5V, IR= 100µA, FEEDBACK pin shorted to GND,

OUT

= 25˚C; limits in Boldface type apply over the Operating

J

LM614I

(Note 6)

LM614C

Limits

(Note 7)

=∞, 450 1000 µA max

+

≤ 36V (32V for LM614C) 550 1070 µA max

2.9 3 V min

46 32 V max
43 32 V max

+

≤ 32V for LM614C) 2.0 7.0 mV max

15

11 40 nA max

0.3 5 nA max

4 pA/˚C

≤ +70˚C

J

Units

µV/˚C

max

R

IN

Input Resistance Differential 1800 MΩ

Common-Mode 3800 MΩ

C

IN

e

n

I

n

Input Capacitance Common-Mode Input 5.7 pF
Voltage Noise f = 100 Hz, Input Referred 74

Current Noise f = 100 Hz, Input Referred 58

CMRR Common-Mode V+= 30V, 0V ≤ VCM≤ (V+− 1.8V), 95 75 dB min

Rejection Ratio CMRR = 20 log (∆V

PSRR Power Supply 4V ≤ V

+

≤ 30V, VCM=V+/2, 110 75 dB min

Rejection Ratio PSRR = 20 log (∆V

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/∆VOS) 90 70 dB min

CM

+

/∆VOS) 100 70 dB min

Electrical Characteristics (Continued)

These specifications apply for V−= GND = 0V, V+= 5V, VCM=V
unless otherwise specified. Limits in standard typeface are for T

Temperature Range .

Symbol Parameter Conditions Typ

A

V

SR Slew Rate V

GBW Gain Bandwidth C

V

O1

V

O2

I

OUT

I

SINK

I

SHORT

Open Loop RL=10kΩto GND, V+= 30V, 500 94 V/mV
Voltage Gain 5V ≤ V

+

L

≤ 25V 50 40 min

OUT

= 30V (Note 8)

= 50 pF 0.8 MHz

Output Voltage RL=10kΩto GND V+− 1.4 V+− 1.8 V min
Swing High V
Output Voltage RL=10kΩto V
Swing Low V
Output Source V

Output Sink V
Current V
Short Circuit Current V

+

= 36V (32V for LM614C) V+− 1.6 V+− 1.9 V min

+

= 36V (32V for LM614C) V−+ 0.9 V−+ 1.0 V max

= 2.5V, V

OUT

V

= −0.3V 15 13 mA min

−IN

= 1.6V, V

OUT

= 0.3V 98mA min

−IN

= 0V, V

OUT

V

= 2V, Source 40 60 mA max

−IN

V

= 5V, V

OUT

V

= 3V, Sink 32 90 mA max

−IN

+

+IN

+IN

+IN

+IN

VOLTAGE REFERENCE

V

R

Voltage Reference (Note 9) 1.244 1.2191 V min

Average Temperature (Note 10) 10 150 PPM/˚C
Drift max
Hysteresis (Note 11)

= 2.5V, IR= 100µA, FEEDBACK pin shorted to GND,

OUT

= 25˚C; limits in Boldface type apply over the Operating

J

= 0V, 25 16 mA min

= 0V, 17 13 mA min

= 3V, 30 50 mA max

= 2V, 30 70 mA max

(Note 6)

LM614I

LM614C

Units

Limits

(Note 7)

±

±

0.70

0.65

±

0.50 V/µs

±

0.45

0.52 MHz

V−+ 0.8 V−+ 0.95 V max

1.2689 V max

±

(

2.0%)

3.2 µV/˚C

LM614

VRChange V
with Current 0.1 1.1 mV max

V
(Note 12) 2.0 5.5 mV max

R Resistance ∆V

∆V
VRChange V
with High V

RO

(3.76V between Anode and 2.8 10 mV max

FEEDBACK)
VRChange with V

+

V

Change (V+= 32V for LM614C) 0.1 1.3 mV max

V

I

FB

FEEDBACK Bias V
Current 29 55 nA max

e

n

Voltage Noise BW = 10 Hz to 10 kHz, 30 µV

R(100 µA)−VR(17 µA)

R(10 mA)−VR(100 µA)

R(10→0.1 mA)
R(100→17 µA)

R(Vro = Vr)−VR(Vro = 5.0V)

R(V + = 5V)−VR(V + = 36V)

R(V + = 5V)−VR(V + = 3V)

/9.9 mA 0.2 0.56 Ω max
/83 µA 0.6 13 Ω max

0.05 1 mV max

1.5 5 mV max

2.5 7 mV max

0.1 1.2 mV max

0.01 1 mV max

0.01 1.5 mV max

≤ VFB≤ 5.06V 22 50 nA max

ANODE

RMS

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Electrical Characteristics (Continued)

These specifications apply for V−= GND = 0V, V+= 5V, VCM=V

LM614

unless otherwise specified. Limits in standard typeface are for T

Temperature Range .

Symbol Parameter Conditions Typ

V

RO=VR

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
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 usingT

soldered to copper-clad board with dissipation from one comparator or reference output transistor, nominal θ

Note 5: Human body model, 100 pF discharged through a 1.5 kΩ resistor.
Note 6: Typical values in standard typeface are for T

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

Note 9: V
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

10
is guaranteed by design and sample testing.

Note 11: Hysteresis is the change in V
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.

is the Cathode-feedback voltage, nominally 1.244V.

R

6

∆VR/(V

•

∆TJ), where ∆VRis the lowest value subtracted from the highest, V

•

R[25˚C]

+

is allowed.

J=TA+PDθjA

= 25˚C; values in boldface type apply for the full operating temperature range. These values represent the

J

@

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.

caused by a change in TJ, after the reference has been “dehysterized”. To dehysterize the reference; that is minimize the

R

. Thegiventhermalresistance is worst-case for packages in sockets in still air.For packages

Typical Performance Characteristics (Reference) T

= 0V, unless otherwise noted

Reference Voltage vs.

Temperature on 5 Representative Units Reference Voltage Drift

= 2.5V, IR= 100µA, FEEDBACK pin shorted to GND,

OUT

= 25˚C; limits in Boldface type apply over the Operating

J

LM614I

(Note 6)

LM614C

Limits

(Note 7)

is 90˚C/W for the WM package.

jA

is the value at 25˚C, and ∆TJis the temperature range. This parameter

R[25˚C]

= 25˚C, FEEDBACK pin shorted to V

J

Units

−

00932647

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00932648

Typical Performance Characteristics (Reference) T

= 25˚C, FEEDBACK pin shorted to V

J

= 0V, unless otherwise noted (Continued)

Accelerated Reference Voltage Drift vs. Time Reference Voltage vs. Current and Temperature

LM614

−

00932649

00932650

Reference Voltage vs. Current and Temperature Reference Voltage vs. Reference Current

00932651

00932652

Reference Voltage vs. Reference Current Reference AC Stability Range

00932653

00932654

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Typical Performance Characteristics (Reference) T

= 0V, unless otherwise noted (Continued)

LM614

FEEDBACK Current vs. FEEDBACK-to-Anode Voltage FEEDBACK Current vs. FEEDBACK-to-Anode Voltage

00932655 00932656

Reference Noise Voltage vs. Frequency Reference Small-Signal Resistance vs. Frequency

= 25˚C, FEEDBACK pin shorted to V

J

−

00932657 00932658

Reference Power-Up Time Reference Voltage with FEEDBACK Voltage Step

00932659 00932660

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Typical Performance Characteristics (Reference) T

= 0V, unless otherwise noted (Continued)

Reference Step Response for 100 µA ∼ 10 mA Current

Reference Voltage with 100∼12 µA Current Step

= 25˚C, FEEDBACK pin shorted to V

J

Step

LM614

−

00932661

Reference Voltage Change with Supply Voltage Step

00932663

Typical Performance Characteristics (Op Amps) V

V

=V+/2, TJ= 25˚C, unless otherwise noted

OUT

Input Common-Mode Voltage Range vs. Temperature V

vs. Junction Temperature on 9 Representative Units

OS

00932662

+

= 5V, V−= GND = 0V, VCM=V+/2,

00932664

00932665

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Typical Performance Characteristics (Op Amps) V

V

LM614

=V+/2, TJ= 25˚C, unless otherwise noted (Continued)

OUT

Input Bias Current vs. Common-Mode Voltage Slew Rate vs. Temperature and Output Sink Current

00932666 00932667

Large-Signal Step Response Output Voltage Swing vs. Temp. and Current

+

= 5V, V−= GND = 0V, VCM=V+/2,

00932668

00932669

Output Source Current vs. Output Voltage and Temp. Output Sink Current vs. Output Voltage and Temp.

00932670

00932671

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Typical Performance Characteristics (Op Amps) V

V

=V+/2, TJ= 25˚C, unless otherwise noted (Continued)

OUT

Output Swing, Large Signal Output Impedance vs. Frequency and Gain

+

= 5V, V−= GND = 0V, VCM=V+/2,

LM614

00932672

00932673

Small-Signal Pulse Response vs. Temp. Small-Signal Pulse Response vs. Load

00932674 00932675

Op Amp Voltage Noise vs. Frequency Op Amp Current Noise vs. Frequency

00932676 00932677

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Typical Performance Characteristics (Op Amps) V

V

LM614

=V+/2, TJ= 25˚C, unless otherwise noted (Continued)

OUT

Small-Signal Voltage Gain vs. Frequency and

Temperature Small-Signal Voltage Gain vs. Frequency and Load

00932678 00932679

Follower Small-Signal Frequency Response Common-Mode Input Voltage Rejection Ratio

+

= 5V, V−= GND = 0V, VCM=V+/2,

00932680

00932681

Power Supply Current vs. Power Supply Voltage Positive Power Supply Voltage Rejection Ratio

00932607

00932621

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Typical Performance Characteristics (Op Amps) V

V

=V+/2, TJ= 25˚C, unless otherwise noted (Continued)

OUT

+

= 5V, V−= GND = 0V, VCM=V+/2,

Negative Power Supply Voltage Rejection Ratio Input Offset Current vs. Junction Temperature

LM614

00932622

Input Bias Current vs. Junction Temperature

00932638

Typical Performance Distributions

Average VOSDrift Industrial Temperature Range Average VOSDrift Commercial Temperature Range

00932624

00932630 00932631

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Typical Performance Distributions (Continued)

LM614

Average I

Voltage Reference Broad-BandNoise Distribution Op Amp Voltage Noise Distribution

Drift Industrial Temperature Range Average IOSDrift Commercial Temperature Range

OS

00932633 00932634

00932635

Op Amp Current Noise Distribution

00932637

00932636

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Application Information

VOLTAGE REFERENCE
Reference Biasing

The voltage reference is of a shunt regulator topology that
models as a simple zener diode. With current I
“forward” direction there is the familiar diode transfer func­tion. I

flowing in the reverse direction forces the reference

r

voltage to be developed from cathode to anode. The cath­ode may swing from a diode drop below V
voltage or to the avalanche voltage of the parallel protection
diode, nominally 7V. A 5.0V reference with V
lowed.

flowing in the

r

−

to the reference

+

=3Visal-

LM614

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.

00932609

FIGURE 1. Voltages Associated with Reference

(Current Source I

The reference equivalent circuit reveals how V

is External)

r

is held at the

r

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 I

, has small

r

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 I

.

r

Adjustable Reference

The FEEDBACK pin allows the reference output voltage,
V

, to vary from 1.24V to 5.0V. The reference attempts to

ro

hold V

at 1.24V. If Vris above 1.24V, the reference will

r

conduct current from Cathode to Anode; FEEDBACK current
always remains low. If FEEDBACK is connected to Anode,
then V

=Vr= 1.24V. For higher voltages FEEDBACK is

ro

held at a constant voltage above Anode— say 3.76V for V
= 5V. Connecting a resistor across the constant Vrgenerates
a current I=V

/R1 flowing from Cathode into FEEDBACK

r

node.AThevenin equivalent 3.76V is generated from FEED­BACK to Anode with R2=3.76/I. For a 1% error, use R1 such
that I is greater than one hundred times the FEEDBACK bias
current. For example, keep I ≥ 5.5µA.

00932610

FIGURE 2. Reference Equivalent Circuit

00932611

FIGURE 3. 1.2V Reference

ro

00932612

FIGURE 4. Thevenin Equivalent

of Reference with 5V Output

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Application Information (Continued)

LM614

R1 = Vr/I = 1.24/32µ = 39k
R2 = R1 {(Vro/Vr) − 1} = 39k {(5/1.24) − 1)} = 118k

00932613

FIGURE 5. Resistors R1 and R2 Program

Reference Output Voltage to be 5V

Understanding that V

is fixed and that voltage sources,

r

resistors, and capacitors may be tied to the FEEDBACK pin,
a range of V

temperature coefficients may be synthesized.

r

00932614

FIGURE 6. Output Voltage has Negative Temperature

Coefficient (TC) if R2 has Negative TC

00932616

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.

00932617

I = Vr/R1 = 1.24/R1

FIGURE 9. Current Source is Programmed by R1

00932615

FIGURE 7. Output Voltage has Positive TC

if R1 has Negative TC

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00932618

FIGURE 10. Proportional-to-Absolute-Temperature

Current Source

Application Information (Continued)

00932619

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.

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 42µA pull-down will bring

the output within 300 mV of V
ture range. If more than 42µA 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

−

over the military tempera-

+

, at the cost

of poorer sinking open-loop voltage gain

2. Cross-over Distortion: The LM614 has lower cross-over

distortion (a 1 V

deadband versus 3 VBEfor the

BE

LM124), and increased slew rate as shown in the char­acteristic curves. Aresistor 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 r

until the output resistance is that of

e

the current limit 25Ω. 200pF may then be driven without
oscillation.

Op Amp Input Stage

The lateral PNP input transistors, unlike most op amps, have
BV

equal to the absolute maximum supply voltage. Also,

EBO

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.

LM614

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Typical Applications

LM614

00932642

FIGURE 12. Simple Low Quiescent Drain Voltage Regulator. Total supply current approximately 320µA, when VIN=

+5V.

*10k must be low
t.c. trimpot.

FIGURE 13. Ultra Low Noise 10.00V Reference. Total output noise is typically 14µV

V

=(R1/Pe+1)V

OUT

R1,R2should be 1% metal film
P

should be low T.C. trim pot

β

REF

00932643

00932644

RMS

.

FIGURE 14. Slow Rise Time Upon Power-Up, Adjustable Transducer Bridge Driver. Rise time is approximately 1ms.

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Typical Applications (Continued)

LM614

00932645

FIGURE 15. Transducer Data Acquisition System. Set zero code voltage, then adjust 10Ω gain adjust pot for full

scale.

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Simplified Schematic Diagrams

LM614

Op Amp

00932602

Reference / Bias

00932603

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Physical Dimensions inches (millimeters)

unless otherwise noted

LM614 Quad Operational Amplifier and Adjustable Reference

16-Lead Molded Small Outline Package (WM)

NS Package Number M16B

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can be reasonably expected to cause the failure of
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labeling, can be reasonably expected to result in a
significant injury to the user.

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Email: [e-mail]

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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.

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