
OBSOLETE
SNOSBS5B – APRIL 1998 – REVISED APRIL 2013
LM108/LM208/LM308 Operational Amplifiers
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FEATURES
DESCRIPTION
The LM108 series are precision operational amplifiers
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Maximum input bias current of 3.0 nA over
having specifications a factor of ten better than FET
temperature
amplifiers over a
55°C to +125°C temperature
Offset current less than 400 pA over
range.
temperature
The devices operate with supply voltages from ±2V to
Supply current of only 300
μA, even in
±20V and have sufficient supply rejection to use
saturation
unregulated
supplies.
Although
the
circuit
is
Specified drift characteristics
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 LM108 series makes
possible many designs that are not practical with
conventional amplifiers. In fact, it operates from 10
M
Ω source resistances, introducing less error than
devices like the 709 with 10 k
Ω sources. Integrators
with drifts less than 500
μV/sec and analog time
delays in excess of one hour can be made using
capacitors no larger than 1
μF.
The LM108 is guaranteed from
55°C to +125°C, the
LM208 from
25°C to +85°C, and the LM308 from
0°C to +70°C.
COMPENSATION CIRCUITS
spacer
(1)
Improves rejection of power supply noise
by a factor of ten.
CO = 30 pF
**Bandwidth and slew rate are proportional
to 1/Cs
to 1/Cf
Figure 2. Alternate Frequency Compensation
Figure 1. Standard Compensation Circuit
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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PRODUCTION DATA information is current as of publication date.
Copyright 1998–2013, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.