NSC LM108MW8, LM108AWG-883, LM108AW-MLS, LM108AJ-883, LM108AH-883 Datasheet

May 1989

LM108A/LM208A/LM308A Operational Amplifiers

General Description

The LM108/LM108A series are precision operational amplifiers having specifications about a factor of ten better than FET amplifiers over their operating temperature range. In addition to low input currents, these devices have extremely low offset voltage, making it possible to eliminate offset adjustments, in most cases, and obtain performance approaching chopper stabilized amplifiers.

The devices operate with supply voltages from g2V to g18V and have sufficient supply rejection to use unregulated supplies. Although the circuit is interchangeable with and uses the same compensation as the LM101A, an alternate compensation scheme can be used to make it particularly insensitive to power supply noise and to make supply bypass capacitors unnecessary.

The low current error of the LM108A series makes possible many designs that are not practical with conventional amplifiers. In fact, it operates from 10 MX source resistances,

introducing less error than devices like the 709 with 10 kX sources. Integrators with drifts less than 500 mV/sec and analog time delays in excess of one hour can be made using capacitors no larger than 1 mF.

The LM208A is identical to the LM108A, except that the LM208A has its performance guaranteed over a b25§C to a85§C temperature range, instead of b55§C to a125§C. The LM308A devices have slightly-relaxed specifications and performances over a 0§C to a70§C temperature range.

Features

YOffset voltage guaranteed less than 0.5 mV

YMaximum input bias current of 3.0 nA over temperature

YOffset current less than 400 pA over temperature

YSupply current of only 300 mA, even in saturation

YGuaranteed 5 mV/§C drift

Compensation Circuits

Standard Compensation Circuit

Alternate* Frequency Compensation

	R1 CO
	R1aR2		*Improves
	30 pF		noise
TL/H/7759 ± 1			TL/H/7759 ± 2

**Bandwidth and slew rate are proportional to 1/Cf .

**Bandwidth and slew rate are proportional to 1/Cs .

Feedforward Compensation

TL/H/7759 ± 3

Amplifiers Operational LM108A/LM208A/LM308A

C1995 National Semiconductor Corporation

TL/H/7759

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

b25§C s TA s 85§C.

LM108A/LM208A Absolute Maximum Ratings

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

(Note 5)

Supply Voltage	g20V
Power Dissipation (Note 1)	500 mW
Differential Input Current (Note 2)	g10 mA
Input Voltage (Note 3)	g15V
Output Short-Circuit Duration	Continuous
Operating Free Air Temperature Range	b55§C to a125§C
LM108A
LM208A	b25§C to a85§C

Electrical Characteristics (Note 4)

Storage Temperature Range	b65§C to a150§C
Lead Temperature (Soldering, 10 sec.) (DIP)		260§C
Soldering Information
Dual-In-Line Package		260§C
Soldering (10 sec.)
Small Outline Package		215§C
Vapor Phase (60 sec.)
Infrared (15 sec.)		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 6)

2000V

Parameter	Conditions	Min	Typ	Max	Units
Input Offset Voltage	TA e 25§C		0.3	0.5	mV
Input Offset Current	TA e 25§C		0.05	0.2	nA
Input Bias Current	TA e 25§C		0.8	2.0	nA
Input Resistance	TA e 25§C	30	70		MX
Supply Current	TA e 25§C		0.3	0.6	mA
Large Signal Voltage Gain	TA e 25§C, VS e g15V,	80	300		V/mV
	VOUT e g10V, RL t 10 kX
Input Offset Voltage				1.0	mV
Average Temperature Coefficient			1.0	5.0	mV/§C
of Input Offset Voltage
Input Offset Current				0.4	nA
Average Temperature Coefficient			0.5	2.5	pA/§C
of Input Offset Current
Input Bias Current				3.0	nA
Supply Current	TA e 125§C		0.15	0.4	mA
Large Signal Voltage Gain	VS e g15V, VOUT e g10V,	40			V/mV
	RL t 10 kX
Output Voltage Swing	VS e g15V, RL e 10 kX	g13	g14		V
Input Voltage Range	VS e g15V	g13.5			V
Common Mode Rejection Ratio		96	110		dB
Supply Voltage Rejection Ratio		96	110		dB

Note 1: The maximum junction temperature of the LM108A is 150§C, while that of the LM208A is 100§C. For operating at elevated temperatures, devices in the H08 package must be derated based on a thermal resistance of 160§C/W, junction to ambient, or 20§C/W, junction to case. The thermal resistance of the dual-in-line package is 100§C/W, junction to ambient.

Note 2: The inputs are shunted with back-to-back diodes for overvoltage protection. Therefore, excessive current will flow if a differential input voltage in excess of 1V is applied between the inputs unless some limiting resistance is used.

Note 3: For supply voltages less than g15V, the absolute maximum input voltage is equal to the supply voltage.

Note 4: These specifications apply for g5V s VS s g20V and b55§C s TA s 125§C, unless otherwise specified. With the LM208A, however, all temperature specifications are limited to

Note 5: Refer to RETS108AX for LM108AH and LM108AJ-8 military specifications.

Note 6: Human body model, 1.5 kX in series with 100 pF.

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LM308A Absolute Maximum Ratings

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

Supply Voltage	g18V
Power Dissipation (Note 1)	500 mW
Differential Input Current (Note 2)	g10 mA
Input Voltage (Note 3)	g15V
Output Short-Circuit Duration	Continuous
Operating Temperature Range	0§C to a70§C
Storage Temperature Range	b65§C to a150§C
H-Package Lead Temperature	300§C
(Soldering, 10 sec.)

Electrical Characteristics (Note 4)

Lead Temperature (Soldering, 10 sec.) (DIP)	260§C
Soldering Information
Dual-In-Line Package	260§C
Soldering (10 sec.)
Small Outline Package	215§C
Vapor phase (60 sec.)
Infrared (15 sec.)	220§C

See An-450 ``Surface Mounting Methods and Their Effect on Product Reliability'' for other methods of soldering surface mount devices.

ESD rating to be determined.

Parameter	Conditions	Min	Typ	Max	Units
Input Offset Voltage	TA e 25§C		0.3	0.5	mV
Input Offset Current	TA e 25§C		0.2	1	nA
Input Bias Current	TA e 25§C		1.5	7	nA
Input Resistance	TA e 25§C	10	40		MX
Supply Current	TA e 25§C, VS e g15V		0.3	0.8	mA
Large Signal Voltage Gain	TA e 25§C, VS e g15V,	80	300		V/mV
	VOUT e g10V, RL t 10 kX
Input Offset Voltage	VS e g15V, RS e 100X			0.73	mV
Average Temperature Coefficient	VS e g15V, RS e 100X		2.0	5.0	mV/§C
of Input Offset Voltage
Input Offset Current				1.5	nA
Average Temperature Coefficient			2.0	10	pA/§C
of Input Offset Current
Input Bias Current				10	nA
Large Signal Voltage Gain	VS e g15V, VOUT e g10V,	60			V/mV
	RL t 10 kX
Output Voltage Swing	VS e g15V, RL e 10 kX	g13	g14		V
Input Voltage Range	VS e g15V	g14			V
Common Mode Rejection Ratio		96	110		dB
Supply Voltage Rejection Ratio		96	110		dB

Note 1: The maximum junction temperature of the LM308A is 85§C. For operating at elevated temperatures, devices in the H08 package must be derated based on a thermal resistance of 160§C/W, junction to ambient, or 20§C/W, junction to case. The thermal resistance of the dual-in-line package is 100§C/W, junction to ambient.

Note 2: The inputs are shunted with back-to-back diodes for overvoltage protection. Therefore, excessive current will flow if a differential input voltage in excess of 1V is applied between the inputs unless some limiting resistance is used.

Note 3: For supply voltages less than g15V, the absolute maximum input voltage is equal to the supply voltage.

Note 4: These specifications apply for g5V s VS s g15V and 0§C s TA s a70§C, unless otherwise specified.

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