Texas Instruments INA332AIDGKR

Overview

INA332AIDGKR from Texas Instruments is a rail-to-rail output, low-power CMOS instrumentation amplifier optimized for single-supply sensor signal conditioning. It delivers 2.0MHz bandwidth, 5V/µs slew rate, and 73dB DC CMRR in an MSOP-8 package, with fixed internal gain of 5V/V (extendable to 1000V/V via external resistors). It operates from +2.7V to +5.5V supply and supports industrial temperature range (–55°C to +125°C), making it suitable for bridge-based pressure transducers and portable ECG front-ends.

For engineers reviewing the INA332AIDGKR datasheet, INA332AIDGKR pinout, INA332AIDGKR application, or INA332AIDGKR equivalent, key selection criteria include its 0.5pA input bias current, 415µA quiescent current (0.01µA in shutdown), rail-to-rail output swing within 25mV of rails at G ≥ 10, and MSOP-8 thermal resistance of 150°C/W - all critical for battery-powered precision analog acquisition.

Technical Context

The INA332AIDGKR implements a modified two-op-amp instrumentation architecture with integrated gain amplifier A3, enabling high-precision differential amplification while maintaining low power. Its input stage uses CMOS technology to achieve 10¹³Ω input impedance and sub-picoampere bias current, essential for high-impedance sensors like thermistors and piezoresistive bridges.

Gain is internally set to 5V/V but programmable above 5V/V using external R1/R2 per G = 5 + 5(R2/R1); reference pin (REF) sets output common-mode level and directly impacts input common-mode range. Shutdown pin enables nanosecond transition to 0.01µA sleep mode, supporting multichannel time-division multiplexing without output loading.

Key Specifications

Pinout & Package

VSSOP-8 (DGK) package: 3.0mm × 1.8mm body, 0.65mm pitch, exposed thermal pad (not electrically connected), moisture sensitivity level 2 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD8421ARMZ, INA332AIDGKR trades bandwidth and precision for 3.5× lower power and lower cost; compared with INA333AIDGKR, it offers proven reliability and lower IQ at the expense of higher initial offset - ideal for high-volume industrial sensor modules.

Availability

INA332AIDGKR is available at Aetrix Electronics and suitable for industrial sensor amplifiers, portable medical devices, and field utility meters requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for INA332AIDGKR 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 components.

The INA332AIDGKR belongs to TI's low-power instrumentation amplifier product line, designed specifically for cost-sensitive, battery-operated sensor interfaces demanding rail-to-rail output, wide temperature operation, and minimal external components.

FAQ

What is the maximum gain achievable with INA332AIDGKR?

The INA332AIDGKR supports externally programmable gain from 5V/V to 1000V/V using the equation G = 5 + 5(R2/R1). At G = 1000V/V, bandwidth reduces to ~10kHz, and stability requires careful attention to feedback capacitor placement per Figure 8 in SBOS216B. The internal 5V/V gain stage remains active regardless of external resistor configuration, and gain error remains ≤0.4% across the full range when using 0.1% tolerance resistors with matched temperature coefficients.

Does INA332AIDGKR support true rail-to-rail input common-mode range?

No - the INA332AIDGKR does not support rail-to-rail input common-mode range. Its upper input common-mode limit is (V+) – 1.2V, and lower limit depends on REF voltage per VOA1 = 5/4 VCM – 1/4 VREF. For example, with V+ = 5V and REF = 2.5V, usable VCM spans ~0.55V to 3.8V. Operation beyond these bounds degrades CMRR and may cause saturation; the device is specified only within the documented range of 0.35V to 3.8V depending on supply voltage.

Can INA332AIDGKR drive ADC inputs directly without an output buffer?

Yes - the INA332AIDGKR can directly drive capacitive-input SAR ADCs such as the ADS7818, provided load capacitance stays ≤100pF and settling time requirements allow ≥1.7µs (0.1%) for 2V step at G = 25. Its low output impedance at high frequencies and rail-to-rail swing eliminate need for buffering in most 12-bit systems. For heavier capacitive loads (>500pF) or faster settling (<1µs), TI recommends adding an OPA340 buffer as shown in Figure 5 of SBOS216B.

How does the REF pin affect performance in INA332AIDGKR?

The REF pin defines the output common-mode voltage and directly impacts input common-mode range, CMRR, and offset trimming capability. A series impedance >160Ω on REF degrades CMRR to ≤50dB. REF voltage also determines the lower bound of valid input common-mode range via VOA1 = 5/4 VCM – 1/4 VREF. Applying a correction voltage to REF adds directly to VOUT with unity gain, enabling offset trimming - but requires low-impedance drive (e.g., op-amp buffer) to preserve performance.

Is INA332AIDGKR pin-compatible with INA333AIDGKR?

Yes - INA332AIDGKR and INA333AIDGKR share identical MSOP-8 (DGK) pinout, footprint, and basic functional interface. However, the INA333AIDGKR features improved specifications including lower input offset (±25µV vs ±500µV), better PSRR (105dB vs 80dB), and enhanced ESD protection, while consuming 500µA IQ versus 415µA. No PCB changes are required for migration, but system-level validation of offset and noise performance is recommended due to specification differences.