Texas Instruments PGA204AU

Overview

PGA204AU from Texas Instruments (originally Burr-Brown) is a digitally programmable instrumentation amplifier with four precision gain settings - 1, 10, 100, and 1000 V/V - selected via TTL/CMOS-compatible A0/A1 address inputs. It delivers 50 µV max input-referred offset voltage, 0.25 µV/°C drift, 115 dB CMRR at G=1000, ±40 V input over-voltage protection, and operates from ±4.5 V to ±18 V supplies. It is used in high-accuracy data acquisition systems where gain flexibility and analog integrity are critical.

For engineers reviewing the PGA204AU datasheet, PGA204AU pinout, PGA204AU application, or PGA204AU equivalent, key selection considerations include its SOL-16 surface-mount package, gain-switching settling time (1000 µs at G=1000), input bias current ≤2 nA, output swing limited to (V+)–1.3 V / (V–)+1.3 V, and compatibility with single-supply reference configurations using the Ref pin.

Technical Context

The PGA204AU integrates three op-amp stages: two matched input amplifiers (A1, A2) with laser-trimmed resistive feedback networks for gain selection, and an output difference amplifier (A3) that rejects common-mode error. Its digitally controlled gain is implemented via internal 25 kΩ resistor networks switched by CMOS logic, eliminating external gain-setting components.

It features over-voltage protection on both inputs (±40 V absolute max), input bias current return path requirements (≤±2 nA), and a dedicated digital ground (Pin 14) decoupled from analog ground to preserve CMRR. The Ref pin sets output common-mode level, and the Feedback pin (Pin 12) enables remote-sense accuracy when tied to the load.

Key Specifications

Pinout & Package

SOL-16 surface-mount package (SOIC-DW, 16-pin), RoHS-compliant, MSL Level-3 (260°C peak reflow), –40°C to +85°C operating range.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA128UA and AD8253ARMZ, the PGA204AU uniquely provides parallel TTL/CMOS gain selection with zero external components, making it optimal for deterministic, low-latency gain changes in resource-constrained embedded DAQ systems without SPI infrastructure.

Availability

PGA204AU is available at Aetrix Electronics and suitable for data acquisition systems, medical instrumentation, and industrial sensor interfaces requiring stable component supply, long-term lifecycle support, and RoHS-compliant surface-mount packaging.

Supply support for PGA204AU 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 acquired Burr-Brown in 2000 and maintains legacy precision analog product lines including the PGA204 series.

The PGA204 product line was designed for cost-sensitive, high-accuracy analog signal conditioning in data acquisition and instrumentation applications where programmability, robustness, and ease of use outweigh ultra-high-speed or ultra-low-power requirements.

FAQ

What gain settings does the PGA204AU support, and how are they selected?

The PGA204AU supports four discrete gain settings: 1, 10, 100, and 1000 V/V. These are selected using the logic states of address pins A0 (Pin 15) and A1 (Pin 16) per the truth table in the datasheet. No external components or latching circuitry is required - gain changes occur immediately upon logic transition. This behavior is confirmed for the exact PGA204AU part number in the "Digital Inputs" section of the official datasheet.

Does the PGA204AU require an external logic supply voltage for its digital inputs?

No, the PGA204AU does not require a separate logic supply. Its A0 and A1 inputs are TTL/CMOS-compatible and reference digital ground (Pin 14), which can be connected anywhere between V– and (V+)–4 V. The device draws only ~1 µA from each digital input at logic low, eliminating need for level translators. This feature is explicitly stated in the "DIGITAL LOGIC" specifications table for PGA204AU.

Can the PGA204AU operate from a single supply, and how is the output referenced?

Yes, the PGA204AU can operate from split supplies (±4.5 V to ±18 V) or asymmetric supplies, but it is not designed for true single-supply operation (e.g., 0 V and +15 V). Output common-mode level is set by the Ref pin (Pin 10), which must be driven by a low-impedance source - typically ground or a precision reference. A 5 Ω series resistance on Ref degrades CMRR to ~80 dB, so proper grounding is essential. This requirement applies identically to the PGA204AU variant.

What is the maximum safe input voltage for the PGA204AU, and does it apply with no power applied?

The PGA204AU supports ±40 V absolute maximum input voltage on either input terminal - even when unpowered. Internal over-voltage protection circuitry limits input current to ~1.5 mA under overload, preventing damage. This rating is specified in the Absolute Maximum Ratings table and confirmed for PGA204AU in the "INPUT PROTECTION" application note section. It applies independently to each input (e.g., +40 V on V+IN and –40 V on V–IN simultaneously).

Is the PGA204AU pin-compatible with the PGA205AU, and what is the key functional difference?

No, the PGA204AU and PGA205AU share identical pinout and package (SOL-16), but differ fundamentally in gain architecture: PGA204AU provides G=1/10/100/1000, while PGA205AU provides G=1/2/4/8. Their internal resistor networks and CMRR vs. gain profiles are optimized separately. Substituting one for the other requires logic-level reconfiguration and validation of signal chain bandwidth and offset performance - they are not functionally interchangeable despite mechanical compatibility.