Texas Instruments PGA309 Data Sheet/Manual

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PGA309

SBOS292A − DECEMBER 2003 − REVISED AUGUST 2004

Voltage Output

PROGRAMMABLE SENSOR CONDITIONER

FEATURES DESCRIPTION The PGA309 is a programmable analog signal conditioner

COMPLETE BRIDGE SENSOR CONDITIONER

designed for bridge sensors. The analog signal path am-

VOLTAGE OUTPUT: Ratiometric or Absolute

plifies the sensor signal and provides digital calibration for

DIGITAL CAL: No Potentiometers/Sensor Trims

zero, span, zero drift, span drift, and sensor linearization

SENSOR ERROR COMPENSATION

errors with applied stress (pressure, strain, etc.). The cal-

− Span, Offset, and Temperature Drifts

ibration is done via a One-Wire digital serial interface or

LOW ERROR, TIME-STABLE

through a Two-Wire industry-standard connection. The

SENSOR LINEARIZATION CIRCUITRY calibration parameters are stored in external nonvolatile TEMPERATURE SENSE: Internal or External memory (typically SOT23-5) to eliminate manual trimming CALIBRATION LOOKUP TABLE LOGIC and achieve long-term stability. − Uses External EEPROM (SOT23-5)

The all-analog signal path contains a 2x2 input multiplex-

OVER/UNDER-SCALE LIMITING

er (mux), auto-zero programmable-gain instrumentation

SENSOR FAULT DETECTION amplifier, linearization circuit, voltage reference, internal +2.7V TO +5.5V OPERATION oscillator, control logic, and an output amplifier. Program- −40°C to +125°C OPERATION mable level shifting compensates for sensor DC offsets. SMALL TSSOP-16 PACKAGE

The core of the PGA309 is the precision, low-drift, no 1/f noise Front-End PGA (Programmable Gain Amplifier). APPLICATIONS The overall gain of the Front-End PGA + Output Amplifier can be adjusted from 2.7V/V to 1152V/V. The polarity of

BRIDGE SENSORS

the inputs can be switched through the input mux to ac-

REMOTE 4-20m A TRANSMITTERS

commodate sensors with unknown polarity output. The

STRAIN, LOAD, AND WEIGH SCALES

Fault Monitor circuit detects and signals sensor burnout,

AUTOMOTIVE SENSORS

overload, and system fault conditions. For detailed application information, see the PGA309

EVALUATION TOOLS User’s Guide (SBOU024), available for download at

www.ti.com.

HARDWARE DESIGNER’S KIT (PGA309EVM)

− Temperature Eval of PGA309 + Sensor − Full Programming of PGA309 − Sensor Compensation Analysis Tool

Nonlinear Linearization Ref

Circuit

Bridge PGA309 Transducer Lin DAC

Analog Sensor Linearization

Fault Auto−Zero Over/Under Linear

Monitor PGA Scale Limiter VOUT

Analog Signal Conditioning

Digital Digital Cal

Int Temp

Temperature Compensation

Temp Control Register EEPROM

Ext Temp ADC Interface Circuitry (SOT23−5)

Ext Temp

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners.

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