®
INA121
INA121
INA121
FET-Input, Low Power
INSTRUMENTATION AMPLIFIER
FEATURES
DESCRIPTION
● LOW BIAS CURRENT: ±4pA
The INA121 is a FET-input, low power instrumenta-
tion amplifier offering excellent accuracy. Its versatile
three-op amp design and very small size make it ideal
for a variety of general purpose applications. Low bias
current (±4pA) allows use with high impedance
sources.
● LOW QUIESCENT CURRENT: ±450µA
● LOW INPUT OFFSET VOLTAGE: ±200µV
● LOW INPUT OFFSET DRIFT: ±2µV/°C
● LOW INPUT NOISE:
20nV/√Hz at f = 1kHz (G =100)
Gain can be set from 1V to 10,000V/V with a single
external resistor. Internal input protection can with-
stand up to ±40V without damage.
● HIGH CMR: 106dB
● WIDE SUPPLY RANGE: ±2.25V to ±18V
● LOW NONLINEARITY ERROR: 0.001% max
● INPUT PROTECTION TO ±40V
The INA121 is laser-trimmed for very low offset
voltage (±200µV), low offset drift (±2µV/°C), and
high common-mode rejection (106dB at G = 100). It
operates on power supplies as low as ±2.25V (+4.5V),
allowing use in battery operated and single 5V sys-
tems. Quiescent current is only 450µA.
● 8-PIN DIP AND SO-8 SURFACE MOUNT
APPLICATIONS
Package options include 8-pin plastic DIP and SO-8
surface mount. All are specified for the –40°C to
+85°C industrial temperature range.
● LOW-LEVEL TRANSDUCER AMPLIFIERS
Bridge, RTD, Thermocouple
● PHYSIOLOGICAL AMPLIFIERS
ECG, EEG, EMG, Respiratory
● HIGH IMPEDANCE TRANSDUCERS
● CAPACITIVE SENSORS
● MULTI-CHANNEL DATA ACQUISITION
● PORTABLE, BATTERY OPERATED SYSTEMS
● GENERAL PURPOSE INSTRUMENTATION
V+
7
INA121
2
1
Over-Voltage
Protection
–
VIN
A1
50kΩ
RG
G = 1 +
40kΩ
40kΩ
25kΩ
25kΩ
6
5
A3
VO
RG
8
3
A2
Ref
Over-Voltage
Protection
+
40kΩ
40kΩ
VIN
4
V–
International Airport Industrial Park
•
Mailing Address: PO Box 11400, Tucson, AZ 85734
•
Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706
Telex: 066-6491 FAX: (520) 889-1510
• Tel: (520) 746-1111 • Twx: 910-952-1111
Internet: http://www.burr-brown.com/
•
FAXLine: (800) 548-6133 (US/Canada Only) Cable: BBRCORP
•
•
•
•
Immediate Product Info: (800) 548-6132
®
©1997 Burr-Brown Corporation
PDS-1412A
Printed in U.S.A. May, 1998
1
INA121
SBOS078