SPI Programmable-Gain Amplifier
with Input VOS Trim and Output Op Amp
The MAX9939 is a general-purpose, differential-input
programmable-gain amplifier (PGA) that is ideal for con-
ditioning a variety of wide dynamic range signals such
as those found in motor current-sense, medical instru-
mentation, and sonar data acquisition applications. It
features programmable differential gains from 0.2V/V to
157V/V, input offset-voltage compensation, and an out-
put amplifier that can be configured either as a high-
order active filter or to provide a differential output.
The PGA is optimized for high-signal bandwidth and its
gain can be programmed to be 0.2V/V, 1V/V, 10V/V,
20V/V, 30V/V, 40V/V, 60V/V, 80V/V, 119V/V, and 157V/V.
Precision resistor matching provides extremely low gain
tempco and high CMRR. Although the MAX9939 oper-
ates from a single supply VCC between 2.9V to 5.5V, it
can process signals both above and below ground due
to the use of an input level-shifting amplifier stage.
Furthermore, its inputs are protected to ±16V, allowing it
to withstand fault conditions and signal overranges.
The output amplifier is designed for high bandwidth
and low-bias currents, making it ideal for use in multi-
ple-feedback active filter topologies that offer much
higher Qs and stopband attenuation than Sallen-Key
The MAX9939 draws 3.4mA of quiescent supply current
at 5V, and includes a software-programmable shut-
down mode that reduces its supply current to only
13µA. The MAX9939 is available in a 10-pin µMAX®
package and operates over the -40°C to +125°C auto-
motive temperature range.
Sensorless Motor Control
Medical Signal Conditioning
Sonar and General Purpose Data Acquisition
Differential to Single-Ended Conversion
Differential-Input, Differential-Output Signal
Sensor Interface and Signal Processing
o SPI-Programmable Gains: 0.2V/V to 157V/V
o Extremely Low Gain Tempco
o Integrated Amplifier for R/C Programmable Active
o Input Offset-Voltage Compensation
o Input Protection to ±16V
o 13µA Software Shutdown Mode
o -40°C to +125°C Operating Temperature Range
o 10-Pin µMAX Package
-40°C to +125°C
MAX9939AUB/V+T -40°C to +125°C
/V denotes an automotive-qualified part.
+Denotes a lead(Pb)-free/RoHS-compliant package.
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Functional Diagram appears at end of data sheet.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-4329; Rev 3; 12/12