Texas Instruments PGA281AIPW

Overview

PGA281AIPW from Texas Instruments is a precision, zero-drift, high-voltage programmable gain instrumentation amplifier with digitally controlled binary gain steps from ⅛ V/V to 128 V/V, ±5 μV offset voltage at G = 128, and fully differential rail-to-rail output stage optimized for interfacing with high-resolution ADCs in industrial data acquisition systems.

For engineers reviewing the PGA281AIPW datasheet, PGA281AIPW pinout, PGA281AIPW application, or PGA281AIPW equivalent, this device supports critical design tasks including high-precision signal conditioning of ±15.5 V inputs, overload detection via EF pin, and seamless integration with ΔΣ or SAR ADCs using its VOCM-referenced differential output architecture.

Technical Context

The PGA281AIPW employs proprietary autozeroing and chopper-stabilized techniques to achieve near-zero offset drift (0.5 ppm/°C) and eliminate 1/f noise, enabling stable dc measurement over temperature. Its dual-stage architecture separates high-voltage input amplification (±18 V supply) from low-voltage differential output (2.7–5.5 V), isolating sensitive analog front-end stages from digital supply domains.

Gain is set via five digital control pins (G4–G0) selecting 11 binary steps plus two scaling factors (1× or 1.375×), yielding up to 176 V/V total gain. Internal error detection monitors both input and output stages, asserting the EF pin on overload-critical for fault-tolerant sensor interfaces in test equipment and medical instrumentation.

Key Specifications

Pinout & Package

TSSOP-16 package (PW) with 0.65 mm pitch; thermally enhanced layout supporting 92.6°C/W junction-to-ambient dissipation under standard PCB conditions.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar programmable gain instrumentation amplifier applications.

Compared with INA333AIDGKR and PGA204KP, the PGA281AIPW uniquely combines high-voltage input capability, digital gain programmability, integrated overload detection, and zero-drift performance-making it the only option for demanding, reconfigurable industrial and medical front-ends requiring guaranteed dc accuracy and fault resilience.

Availability

PGA281AIPW is available at Aetrix Electronics and suitable for high-precision signal instrumentation, multiplexed data acquisition, and medical instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for PGA281AIPW includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in precision signal chain solutions.

The PGA281AIPW belongs to TI's high-precision instrumentation amplifier product line, designed specifically for universal analog front-ends in industrial, medical, and test equipment requiring programmable gain, zero-drift stability, and robust fault detection.

FAQ

What is the maximum gain achievable with the PGA281AIPW, and how is it configured?

The PGA281AIPW achieves a maximum gain of 176 V/V by combining the highest binary gain step (128 V/V) with the 1.375× scaling factor enabled via the G4 pin. This configuration is explicitly defined in Table 1 of the datasheet: G3:G0 = 1010 (128 V/V) and G4 = 1 yields 128 × 1.375 = 176 V/V. The PGA281AIPW does not support interpolation or analog gain tuning - all settings are discrete and digitally selected via G4–G0 pins.

How does the EF (Error Flag) pin function in the PGA281AIPW, and what conditions trigger it?

The EF pin on the PGA281AIPW is an open-drain, active-low output that asserts within 30 μs when either input-stage saturation (e.g., IN-P or IN-N exceeding VSP/VSN rails) or output-stage clipping (VO-P or VO-N hitting VSOP/VSON rails) occurs. It remains asserted until the overload condition clears, with 5 μs recovery delay. This feature is integral to the PGA281AIPW's architecture and provides deterministic fault signaling without software polling.

Can the PGA281AIPW drive a 24-bit delta-sigma ADC directly, and what interface requirements must be met?

Yes, the PGA281AIPW is explicitly designed to drive high-resolution delta-sigma ADCs such as the ADS1259. To interface directly, configure VSOP/VSON to match the ADC's supply (e.g., 5 V), bias VOCM to the ADC's common-mode voltage (typically VSOP/2), and terminate VO-P/VO-N differentially into the ADC's input. The PGA281AIPW's 140 dB CMRR and 200 mΩ output impedance ensure minimal noise coupling and full-scale accuracy without external buffering.

What is the operating temperature range for the PGA281AIPW, and how do key parameters shift across this range?

The PGA281AIPW is specified from –40°C to +105°C. Over this range, offset voltage drift remains ≤0.45/G μV/°C (e.g., ≤0.0035 μV/°C at G = 128), gain drift is ≤2 ppm/°C, and CMRR stays ≥116 dB at G = 128. These values are production-tested and guaranteed - not typical-only specs - ensuring reliability in automotive under-hood or industrial control cabinet deployments.

Does the PGA281AIPW require external components for basic operation, and which pins are mandatory connections?

Yes: VOCM must be externally biased (e.g., to VSOP/2 via resistor divider or op-amp buffer); IN-P/IN-N require series current-limiting resistors for overvoltage protection; and DVDD, VSP, VSN, VSOP, VSON must all be decoupled with 100 nF ceramic capacitors. G4–G0 pins must be driven to valid logic levels (not floating) to define gain. The PGA281AIPW will not operate correctly if VOCM is left unconnected or if digital inputs are unterminated.