LM343H - National Semiconductor

TL/H/7783

LM143/LM343 High Voltage Operational Amplifier

February 1995

LM143/LM343 High Voltage

Operational Amplifier

General Description

The LM143 is a general purpose high voltage operational

amplifier featuring operation to g40V, complete input over-

voltage protection up to g40V and input currents compara-

ble to those of other super-bop amps. Increased slew rate,

together with higher common-mode and supply rejection,

insure improved performance at high supply voltages. Oper-

ating characteristics, in particular supply current, slew rate

and gain, are virtually independent of supply voltage and

temperature. Furthermore, gain is unaffected by output

loading at high supply voltages due to thermal symmetry on

the die. The LM143 is pin compatible with general purpose

op amps and has offset null capability.

Application areas include those of general purpose op

amps, but can be extended to higher voltages and higher

output power when externally boosted. For example, when

used in audio power applications, the LM143 provides a

power bandwidth that covers the entire audio spectrum. In

addition, the LM143 can be reliably operated in environ-

ments with large overvoltage spikes on the power supplies,

where other internally-compensated op amps would suffer

catastrophic failure.

The LM343 is similar to the LM143 for applications in less

severe supply voltage and temperature environments.

Features

YWide supply voltage range g4.0V to g40V

YLarge output voltage swing g37V

YWide input common-mode range g38V

YInput overvoltage protection Full g40V

YSupply current is virtually independent of supply voltage

and temperature

Unique Characteristics

YLow input bias current 8.0 nA

YLow input offset current 1.0 nA

YHigh slew rateÐessentially independent of temperature

and supply voltage 2.5V/ms

YHigh voltage gainÐvirtually independent of resistive

loading, temperature, and supply voltage 100k min

YInternally compensated for unity gain

YOutput short circuit protection

YPin compatible with general purpose op amps

Connection Diagram

Metal Can Package

Top View

TL/H/7783–1

Order Number LM143H, LM143H/883*or LM343H

See NS Package Number H08C

*Available per SMDÝ7800303

C1995 National Semiconductor Corporation RRD-B30M115/Printed in U. S. A.

Absolute Maximum Ratings (Note 1)

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

Distributors for availability and specifications.

(Note 4)

LM143 LM343

Supply Voltage g40V g34V

Power Dissipation (Note 1) 680 mW 680 mW

Differential Input Voltage (Note 2) 80V 68V

Input Voltage (Note 2) g40V g34V

Operating Temperature Range b55§Ctoa

125§C0

Ctoa

70§C

Storage Temperature Range b65§Ctoa

150§Cb65§Ctoa

150§C

Output Short Circuit Duration 5 seconds 5 seconds

Lead Temperature (Soldering, 10 sec.) 300§C 300§C

ESD rating to be determined.

Electrical Characteristics (Note 3)

Parameter Conditions LM143 LM343 Units

Min Typ Max Min Typ Max

Input Offset Voltage TAe25§C 2.0 5.0 2.0 8.0 mV

Input Offset Current TAe25§C 1.0 3.0 1.0 10 nA

Input Bias Current TAe25§C 8.0 20 8.0 40 nA

Supply Voltage TAe25§C10 100 10 200 mV/V

Rejection Ratio

Output Voltage Swing TAe25§C, RLt5kX22 25 20 25 V

Large Signal Voltage TAe25§C, VOUT eg10V, 100k 180k 70k 180k V/V

Gain RLt100 kX

Common-Mode TAe25§C80 90 70 90 dB

Rejection Ratio

Input Voltage Range TAe25§Cg24 g26 g22 g26 V

Supply Current (Note 5) TAe25§C 2.0 4.0 2.0 5.0 mA

Short Circuit Current TAe25§C2020mA

Slew Rate TAe25§C, AVe1 2.5 2.5 V/ms

Power Bandwidth TAe25§C, VOUT e40 Vp-p,20k 20k Hz

RLe5kX, THD s1%

Unity Gain Frequency TAe25§C 1.0M 1.0M Hz

Input Offset Voltage TAeMax 6.0 10 mV

TAeMin 6.0 10

Input Offset Current TAeMax 0.8 4.5 0.8 14 nA

TAeMin 1.8 7.0 1.8 14

Input Bias Current TAeMax 5.0 35 5.0 55 nA

TAeMin 16 35 16 55

Large Signal Voltage RLt100 kX,T

AeMax 50k 150k 50k 150k V/V

Gain RLt100 kX,T

AeMin 50k 220k 50k 220k

Output Voltage Swing RLt5.0 kX,T

AeMax 22 26 20 26 V

RLt5.0 kX,T

AeMin 22 25 20 25

Note 1: Absolute maximum ratings are not necessarily concurrent, and care must be taken not to exceed the maximum junction temperature of the LM143 (150§C)

or the LM343 (100§C). For operating at elevated temperatures, devices in the H08 package must be derated based on a thermal resistance of 155§C/W, junction to

ambient, or 20§C/W, junction to case.

Note 2: For supply voltage less than g40V for the LM143 and less than g34V for the LM343, the absolute maximum input voltage is equal to the supply voltage.

Note 3: These specifications apply for VSeg28V. For LM143, TAemax e125§C and TAemin eb

55§C. For LM343, TAemax e70§C and TAemin e

0§C.

Note 4: Refer to RETS143X for LM143H and LM1536H military specifications.

Note 5: The maximum supply currents are guaranteed at VSeg40V for the LM143 and VSeg34V for the LM343.

Schematic Diagram

TL/H/7783–2

Typical Performance Characteristics

Voltage Follower Slew Rate Supply Current Short Circuit Current

Unity Gain Bandwidth Input Noise Voltage Input Noise Current

Common-Mode Rejection Power Supply Rejection Response

Large Signal Frequency

Response

Open Loop Frequency

Response

Voltage Follower Pulse

Inverter Pulse Response

TL/H/7783–4

Typical Performance Characteristics (Continued)

Input Voltage Range Output Voltage Swing Voltage Gain

Supply Current Input Current Voltage Gain

TL/H/7783–3

Application Hints (See AN-127)

The LM143 is designed for trouble free operation at any

supply voltage up to and including the guaranteed maximum

of g40V. Input overvoltage protection, both common-mode

and differential, is 100% tested and guaranteed at the maxi-

mum supply voltage. Furthermore, all possible high voltage

destructive modes during supply voltage turn-on have been

eliminated by design. As with most IC op amps, however,

certain precautions should be observed to insure that the

LM143 remains virtually blow-out proof.

Although output short circuits to ground or either supply can

be sustained indefinitely at lower supply voltages, these

short circuits should be of limited duration when operating at

higher supply voltages. Units can be destroyed by any com-

bination of high ambient temperature, high supply voltages,

and high power dissipation which results in excessive die

temperature. This is also true when driving low impedance

or reactive loads or loads that can revert to low impedance;

for example, the LM143 can drive most general purpose op

amps outside of the maximum input voltage range, causing

heavy current to flow and possibly destroying both devices.

Precautions should be taken to insure that the power sup-

plies never become reversed in polarityÐeven under tran-

sient conditions. With reverse voltage, the IC will conduct

excessive current, fusing the internal aluminum intercon-

nects. Voltage reversal between the power supplies will al-

most always result in a destroyed unit.

In high voltage applications which are sensitive to very low

input currents, special precautions should be exercised. For

example, with high source resistances, care should be tak-

en to prevent the magnitude of the PC board leakage cur-

rents, although quite small, from approaching those of the

op amp input currents. These leakage currents become

larger at 125§C and are made worse by high supply volt-

ages. To prevent this, PC boards should be properly

cleaned and coated to prevent contamination and to pro-

vide protection from condensed water vapor when operat-

ing below 0§C. A guard ring is also recommended to signifi-

cantly reduce leakage currents from the op amp input pins

to the adjacent high voltage pins in the standard op amp pin

connection as shown in

Figure 1. Figures 2, 3

and

show

how the guard ring is connected for the three most common

op amp configurations.

Finally, caution should be exercised in high voltage applica-

tions as electrical shock hazards are present. Since the

negative supply is connected to the case, users may inad-

vertantly contact voltages equal to those across the power

supplies.

The LM143 can be used as a plug-in replacement in most

general purpose op amp applications. The circuits present-

ed in the following section emphasize those applications

which take advantage of the unique high voltage abilities of

the LM143.

Application Hints (See AN-127) (Continued)

TL/H/7783–5

Bottom View

FIGURE 1. Printed Circuit Layout for Input

Guarding with TO-5 Package

R3 aR1 cR2

R1 aR2 eRSOURCE TL/H/7783–7

FIGURE 3. Guarded Non-Inverting Amplifier

R1 eRSOURCE

TL/H/7783–6

FIGURE 2. Guarded Voltage Follower

R3 eR1 cR2

R1 aR2

TL/H/7783–8

FIGURE 4. Guarded Inverting Amplifier

TL/H/7783–14

FIGURE 5. Offset Voltage Adjustment

Typical Applications ³(For more detail see AN-127)

130 Vp-p Drive Across a Floating Load

TL/H/7783–9

g34V Common-Mode Instrumentation Amplifier

AVe#1a2R1

R2 JR5

R4 WHERE: R4 eR6

R5 eR7 TL/H/7783–10

*R2 may be adjustable to trim the gain.

**R7 may be adjusted to compensate for the resistance tolerance of R4–R7 for best CMR.

³The 38V supplies allow for a 5% voltage tolerance. All resistors are (/2 watt, except as noted.

Typical Applications ³(Continued) (For more detail see AN-127)

Tracking g65V, 1 Amp Power Supply with Short Circuit Protection

²Put on common heat sink.

All resistors are (/2 watt, 5%, except as noted.

TL/H/7783–11

³The 38V supplies allow for a 5% voltage tolerance. All resistors are (/2 watt, except as noted.

Typical Applications ³(Continued) (For more detail see AN-127)

90W Audio Power Amplifier with Safe Area Protection

²Put on common heat sink

*34 turns of no. 20 wire on a */8×form

**Adjust R6 to set IQe100 mA TL/H/7783–12

³The 38V supplies allow for a 5% voltage tolerance. All resistors are (/2 watt, except as noted.

Typical Applications ³(Continued) (For more detail see AN-127)

1 Amp Power Amplifier with Short Circuit Protection

TL/H/7783–13

³The 38V supplies allow for a 5% voltage tolerance. All resistors are (/2 watt, except as noted.

LM143/LM343 High Voltage Operational Amplifier

Physical Dimensions inches (millimeters)

Metal Can Package (H)

Order Number LM143H, LM143H/883 or LM343H

NS Package Number H08C

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 2. A critical component is any component of a life

systems which, (a) are intended for surgical implant support device or system whose failure to perform can

into the body, or (b) support or sustain life, and whose be reasonably expected to cause the failure of the life

failure to perform, when properly used in accordance support device or system, or to affect its safety or

with instructions for use provided in the labeling, can effectiveness.

be reasonably expected to result in a significant injury

to the user.

National Semiconductor National Semiconductor National Semiconductor National Semiconductor

Corporation Europe Hong Kong Ltd. Japan Ltd.

1111 West Bardin Road Fax: (

49) 0-180-530 85 86 13th Floor, Straight Block, Tel: 81-043-299-2309

Arlington, TX 76017 Email: cnjwge

tevm2.nsc.com Ocean Centre, 5 Canton Rd. Fax: 81-043-299-2408

Tel: 1(800) 272-9959 Deutsch Tel: (

49) 0-180-530 85 85 Tsimshatsui, Kowloon

Fax: 1(800) 737-7018 English Tel: (

49) 0-180-532 78 32 Hong Kong

Fran3ais Tel: (

49) 0-180-532 93 58 Tel: (852) 2737-1600

Italiano Tel: (

49) 0-180-534 16 80 Fax: (852) 2736-9960

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.