LM2900_LM3900_LM3301.pdf

February 1995

LM2900/LM3900/LM3301 Quad Amplifiers

General Description

The LM2900 series consists of four independent, dual input,

internally compensated amplifiers which were designed

specifically to operate off of a single power supply voltage

and to provide a large output voltage swing. These amplifi-

ers make use of a current mirror to achieve the non-invert-

ing input function. Application areas include: ac amplifiers,

RC active filters, low frequency triangle, squarewave and

pulse waveform generation circuits, tachometers and low

speed, high voltage digital logic gates.

Features

Y Wide single supply voltage 4 V DC to 32 V DC

Range or dual supplies g 2V DC to g 16 V DC

Y Supply current drain independent of supply voltage

Y Low input biasing current 30 nA

Y High open-loop gain 70 dB

Y Wide bandwidth 2.5 MHz (unity gain)

Y Large output voltage swing (V a b 1) Vp-p

Y Internally frequency compensated for unity gain

Y Output short-circuit protection

Schematic and Connection Diagrams

Dual-In-Line and S.O.

TL/H/7936±2

Top View

TL/H/7936±1

Order Number LM2900N, LM3900M, LM3900N or LM3301N

See NS Package Number M14A or N14A

C 1995 National Semiconductor Corporation

TL/H/7936

RRD-B30M115/Printed in U. S. A.

Absolute Maximum Ratings

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

LM2900/LM3900

LM3301

Supply Voltage

32 V DC

28 V DC

g 16 V DC

g 14 V DC

Power Dissipation (T A e 25 § C) (Note 1)

Molded DIP

1080 mW

S.O. Package

765 mW

Input Currents, I IN a or I IN b

20 mA DC

Output Short-Circuit DurationÐOne Amplifier

Continuous

T A e 25 § C (See Application Hints)

Operating Temperature Range

b 40 § Cto a 85 § C

LM2900

b 40 § Cto a 85 § C

LM3900

0 § Cto a 70 § C

Storage Temperature Range

b 65 § Cto a 150 § C

Lead Temperature (Soldering, 10 sec.)

260 § C

Soldering Information

Dual-In-Line Package

Soldering (10 sec.)

260 § C

Small Outline Package

Vapor Phase (60 sec.) 215 § C 215 § C

Infrared (15 sec.) 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 tolerance (Note 7)

2000V

Electrical Characteristics T A e 25 § C, V a e 15 V DC , unless otherwise stated

LM2900

LM3900

LM3301

Parameter

Conditions

Units

Min Typ Max Min Typ Max Min Typ Max

Open Voltage Gain Over Temp.

V/mV

Loop

Voltage Gain

D V O e 10 V DC

1.2 2.8

Inverting Input

Input Resistance

M X

Output Resistance

k X

Unity Gain Bandwidth

Inverting Input

2.5

MHz

Input Bias Current

Inverting Input, V a e 5V DC

30 200

30 300

Inverting Input

Slew Rate

Positive Output Swing

0.5

V/ m s

Negative Output Swing

Supply Current

R L e % On All Amplifiers

6.2 10

6.2 10 mA DC

Output V OUT High

R L e 2k,

I IN b e 0,

13.5

V a e 15.0 V DC I IN a e 0

Voltage

Swing

V OUT Low

I IN b e 10 m A,

0.09 0.2

I IN a e 0

V DC

V OUT High

V a e Absolute I IN b e 0,

Maximum Ratings I IN a e 0

29.5

26.0

R L e % ,

Output Source

6 18

6 10

5 18

Current

Sink

(Note 2)

0.5 1.3

0.5 1.3 mA DC

Capability

I SINK

V OL e 1V, I IN b e 5 m A

Electrical Characteristics (Note 6), V a e 15 V DC , unless otherwise stated (Continued)

LM2900

LM3900

LM3301

Parameter

Conditions

Units

Min Typ Max Min Typ Max Min Typ Max

Power Supply Rejection T A e 25 § C, f e 100 Hz

Mirror Gain

@ 20 m A (Note 3)

0.90 1.0 1.1 0.90 1.0 1.1 0.90 1 1.10

m A/ m A

@ 200 m A (Note 3) 0.90 1.0 1.1 0.90 1.0 1.1 0.90 1 1.10

D Mirror Gain @ 20 m Ato200 m A (Note 3) 2 5 2 5 2 5 %

Mirror Current (Note 4) 10 500 10 500 10 500 m A DC

Negative Input Current T A e 25 § C (Note 5) 1.0 1.0 1.0 mA DC

Input Bias Current Inverting Input 300 300 nA

Note 1: For operating at high temperatures, the device must be derated based on a 125 § C maximum junction temperature and a thermal resistance of 92 § C/W

which applies for the device soldered in a printed circuit board, operating in a still air ambient. Thermal resistance for the S.O. package is 131 § C/W.

Note 2: The output current sink capability can be increased for large signal conditions by overdriving the inverting input. This is shown in the section on Typical

Characteristics.

Note 3: This spec indicates the current gain of the current mirror which is used as the non-inverting input.

Note 4: Input V BE match between the non-inverting and the inverting inputs occurs for a mirror current (non-inverting input current) of approximately 10 m A. This is

therefore a typical design center for many of the application circuits.

Note 5: Clamp transistors are included on the IC to prevent the input voltages from swinging below ground more than approximately b 0.3 V DC . The negative input

currents which may result from large signal overdrive with capacitance input coupling need to be externally limited to values of approximately 1 mA. Negative input

currents in excess of 4 mA will cause the output voltage to drop to a low voltage. This maximum current applies to any one of the input terminals. If more than one

of the input terminals are simultaneously driven negative smaller maximum currents are allowed. Common-mode current biasing can be used to prevent negative

input voltages; see for example, the ``Differentiator Circuit'' in the applications section.

Note 6: These specs apply for b 40 § C s T A s a 85 § C, unless otherwise stated.

Note 7: Human body model, 1.5 k X in series with 100 pF.

Application Hints

When driving either input from a low-impedance source, a

limiting resistor should be placed in series with the input

lead to limit the peak input current. Currents as large as

20 mA will not damage the device, but the current mirror on

the non-inverting input will saturate and cause a loss of mir-

ror gain at mA current levelsÐespecially at high operating

temperatures.

Precautions should be taken to insure that the power supply

for the integrated circuit never becomes reversed in polarity

or that the unit is not inadvertently installed backwards in a

test socket as an unlimited current surge through the result-

ing forward diode within the IC could cause fusing of the

internal conductors and result in a destroyed unit.

Output short circuits either to ground or to the positive pow-

er supply should be of short time duration. Units can be

destroyed, not as a result of the short circuit current causing

metal fusing, but rather due to the large increase in IC chip

dissipation which will cause eventual failure due to exces-

sive junction temperatures. For example, when operating

from a well-regulated a 5V DC power supply at T A e 25 § C

with a 100 k X shunt-feedback resistor (from the output to

the inverting input) a short directly to the power supply will

not cause catastrophic failure but the current magnitude will

be approximately 50 mA and the junction temperature will

be above T J max. Larger feedback resistors will reduce the

current, 11 M X provides approximately 30 mA, an open cir-

cuit provides 1.3 mA, and a direct connection from the out-

put to the non-inverting input will result in catastrophic fail-

ure when the output is shorted to V a as this then places the

base-emitter junction of the input transistor directly across

the power supply. Short-circuits to ground will have magni-

tudes of approximately 30 mA and will not cause cata-

strophic failure at T A e 25 § C.

Unintentional signal coupling from the output to the non-in-

verting input can cause oscillations. This is likely only in

breadboard hook-ups with long component leads and can

be prevented by a more careful lead dress or by locating the

non-inverting input biasing resistor close to the IC. A quick

check of this condition is to bypass the non-inverting input

to ground with a capacitor. High impedance biasing resis-

tors used in the non-inverting input circuit make this input

lead highly susceptible to unintentional AC signal pickup.

Operation of this amplifier can be best understood by notic-

ing that input currents are differenced at the inverting-input

terminal and this difference current then flows through the

external feedback resistor to produce the output voltage.

Common-mode current biasing is generally useful to allow

operating with signal levels near ground or even negative as

this maintains the inputs biased at a V BE . Internal clamp

transistors (see note 5) catch-negative input voltages at ap-

proximately b 0.3 V DC but the magnitude of current flow has

to be limited by the external input network. For operation at

high temperature, this limit should be approximately 100 m A.

This new ``Norton'' current-differencing amplifier can be

used in most of the applications of a standard IC op amp.

Performance as a DC amplifier using only a single supply is

not as precise as a standard IC op amp operating with split

supplies but is adequate in many less critical applications.

New functions are made possible with this amplifier which

are useful in single power supply systems. For example,

biasing can be designed separately from the AC gain as was

shown in the ``inverting amplifier,'' the ``difference integra-

tor'' allows controlling the charging and the discharging of

the integrating capacitor with positive voltages, and the ``fre-

quency doubling tachometer'' provides a simple circuit

which reduces the ripple voltage on a tachometer output DC

voltage.

Typical Performance Characteristics

Open Loop Gain

Voltage Gain

Large Signal Frequency

Input Current

Supply Current

Response

Output Sink Current

Output Class-A Bias Current

Output Source Current

Supply Rejection

Mirror Gain

Maximum Mirror Current

TL/H/7936±9

Typical Applications (V a e 15 V DC )

Inverting Amplifier

Triangle/Square Generator

V ODC e

V a

A V j b

TL/H/7936±3

TL/H/7936±4

Frequency-Doubling Tachometer

Low V IN b V OUT Voltage Regulator

TL/H/7936±5

TL/H/7936±6

Non-Inverting Amplifier

Negative Supply Biasing

V ODC e

V a

R3 V b

A V j

V ODC e

TL/H/7936±7

A V j

TL/H/7936±8

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