®
OPA121
Low Cost Precision
Difet
®
OPERATIONAL AMPLIFIER
FEATURES
q
LOW NOISE: 6nV/√Hz typ at 10kHz
q
LOW BIAS CURRENT: 5pA max
q
LOW OFFSET: 2mV max
q
LOW DRIFT: 3
µ
V/
°
C typ
q
HIGH OPEN-LOOP GAIN: 110dB min
q
HIGH COMMON-MODE
REJECTION: 86dB min
APPLICATIONS
q
OPTOELECTRONICS
q
DATA ACQUISITION
q
TEST EQUIPMENT
q
MEDICAL EQUIPMENT
q
RADIATION HARD EQUIPMENT
DESCRIPTION
The OPA121 is a precision monolithic dielectrically-
isolated FET (
Difet
®
) operational amplifier. Out-
standing performance characteristics are now
available for low-cost applications.
Noise, bias current, voltage offset, drift, open-loop
gain, common-mode rejection, and power supply
rejection are superior to BIFET
®
amplifiers.
Very low bias current is obtained by dielectric
isolation with on-chip guarding.
Laser-trimming of thin-film resistors gives very low
offset and drift. Extremely low noise is achieved with
new circuit design techniques (patented). A new
cascode design allows high precision input specifica-
tions and reduced susceptibility to flicker noise.
Standard 741 pin configuration allows upgrading of
existing designs to higher performance levels.
Case (TO-99) and Substrate
8
7
+V
CC
–In
2
3
+In
Noise-Free
Cascode*
6
Output
Trim 10k
Ω
1
5
Trim 10k
Ω
2kΩ
2kΩ
4
*Patented
OPA121 Simplified Circuit
–V
CC
2kΩ
2kΩ
Difet
®
, Burr-Brown Corp.
BIFET
®
, National Semiconductor Corp.
International Airport Industrial Park • Mailing Address: PO Box 11400
Tel: (520) 746-1111 • Twx: 910-952-1111 • Cable: BBRCORP •
© 1984 Burr-Brown Corporation
• Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd. • Tucson, AZ 85706
Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132
PDS-539F
Printed in U.S.A. September, 1993
BURR-BROWN [ BURR-BROWN CORPORATION ]
