1FEATURES

? Digital Calibration for Bridge Sensors

? Offset Select: Coarse and Fine

? Gain Select: Coarse and Fine

? Bridge Fault Monitor

? Input Mux for Lead Swap

? Over/Under Scale Limits

? D OUT/ VOUT Clamp Function

? Seven Banks OTP Memory

? One-Wire Digital UART Interface

? Operating Voltage: 2.7 V to 5.5 V

APPLICATIONS

? Bridge Sensors

? Remote Transmitters

? Strain, Load, Weigh Scales

? Automotive Sensors

DESCRIPTION

The PGA308 is a programmable analog sensor signal conditioner. The analog signal path amplifies the sensor

signal and provides digital calibration for offset and gain. Calibration is done via the 1W pin, a digital One-Wire,

UART-compatible interface. For three-terminal sensor modules, 1W may be connected to VOUT and the assembly

programmed through the VOUT pin. Gain and offset calibration parameters are stored onboard in seven banks of

one-time programmable (OTP) memory. The power-on reset (POR) OTP bank may be programmed a total of

four times.

The all-analog signal path contains a 2×2 input multiplexer (mux) to allow electronic sensor lead swapping, a

coarse offset adjust, an auto-zero programmable gain instrumentation amplifier (PGA), a fine gain adjust, a fine

offset adjust, and a programmable gain output amplifier. Fault monitor circuitry detects and signals sensor

burnout, overload, and system fault conditions. Over/under-scale limits provide additional means for system level

diagnostics. The dual-use DOUT/VCLAMP pin can be used as a programmable digital output or as a VOUT overvoltage

clamp.