1 Features
• Low offset voltage: 50 μV, maximum
• Low drift: 0.5 μV/°C, maximum
• Low input bias current: 5 nA, maximum
• Low noise: 8 nV/√Hz, 0.2 μVpp
• High CMR: 120 dB, minimum
• Bandwidth: 1.3 MHz (G = 1)
• Inputs protected to ±40 V
• Wide supply range: ±2.25 V to ±18 V
• Low quiescent current: 700 μA
• Packages: 8-pin plastic DIP, SO-8

2 Applications
• Pressure transmitter
• Temperature transmitter
• Weigh scale
• Electrocardiogram (ECG)
• Analog input module
• Data acquisition (DAQ)

3 Description
The INA128 and INA129 (INA12x) are low-power,
general-purpose instrumentation amplifiers that offer
excellent accuracy. The versatile three op amp design
and small size make these amplifiers an excellent
choice for a wide range of applications. Currentfeedback
input circuitry provides wide bandwidth even
at high gain (200 kHz at G = 100).
A single external resistor sets any gain from 1 to
10,000. The INA128 provides an industry-standard
gain equation with a 50-kΩ resistor. The INA129 gain
equation uses a 49.4-kΩ resistor to allow for drop-in
replacements of comparable devices.
The INA12x are available in plastic DIP and surfacemount
packages, specified for the –40°C to +85°C
temperature range. The INA128 is also available in a
dual configuration, the INA2128.
The upgraded INA828 offers a lower input bias
current (0.6 nA, max) and lower noise (7 nV/√Hz)
at the same quiescent current. See the Device
Comparison Table for a selection of precision
instrumentation amplifiers from Texas Instruments.