Texas Instruments INA333AIDGKTG4

Overview

INA333AIDGKTG4 from Texas Instruments is a micro-power (50 μA), zero-drift, rail-to-rail output instrumentation amplifier designed for precision DC-coupled signal conditioning in low-voltage systems. It delivers 25 μV max offset voltage (G ≥100), 0.1 μV/°C drift, and 50 nV/√Hz input voltage noise at G = 100 - enabling high-accuracy bridge and sensor amplification in battery-powered medical and industrial equipment.

For engineers reviewing the INA333AIDGKTG4 datasheet, INA333AIDGKTG4 pinout, INA333AIDGKTG4 application, or INA333AIDGKTG4 equivalent, key selection criteria include its 1.8 V to 5.5 V single-supply operation, RFI-filtered inputs, gain-setting via single external resistor (G = 1 + 100 kΩ/R_G), and guaranteed performance over –40°C to +125°C.

Technical Context

The INA333AIDGKTG4 implements a three-op-amp architecture with laser-trimmed internal resistors to achieve 100 dB minimum CMRR (G ≥10) and low gain error (±0.07% typ at G = 100). Its auto-calibration core operates at 350 kHz with zero-correction every 8 μs, eliminating flicker noise and aliasing while maintaining continuous signal path integrity.

Input common-mode range extends from (V–) + 0.1 V to (V+) – 0.1 V; output swings to within 50 mV of rails at 5.5 V supply and 10 kΩ load. RFI filtering on both inputs suppresses high-frequency interference without external components, supporting robust operation in noisy environments like ECG front-ends or weigh-scale transducer interfaces.

Key Specifications

Pinout & Package

INA333AIDGKTG4 is packaged in an 8-pin VSSOP (DGK) with 3.00 mm × 3.00 mm body size and exposed thermal pad on underside for enhanced thermal performance in compact PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD8421ARMZ and INA826AIDR, the INA333AIDGKTG4 uniquely combines micro-power operation (50 μA), true zero-drift performance (<0.1 μV/°C), and integrated RFI filtering - making it optimal for battery-powered, high-accuracy sensor front-ends where power, DC stability, and EMC robustness are jointly constrained.

Availability

INA333AIDGKTG4 is available at Aetrix Electronics and suitable for bridge amplifiers, ECG monitors, and pressure sensor signal conditioning requiring stable component supply, long-term calibration retention, and extended temperature operation.

Supply support for INA333AIDGKTG4 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 company specializing in analog and embedded processing technologies, with leadership in precision signal chain solutions.

The INA333 product line was engineered for ultra-low-power, high-DC-accuracy instrumentation in space-constrained, battery-operated systems - targeting medical diagnostics, portable test equipment, and industrial IoT sensor nodes.

FAQ

What is the maximum gain achievable with INA333AIDGKTG4?

The INA333AIDGKTG4 supports gains from 1 to 1000 using a single external resistor RG per the equation G = 1 + 100 kΩ/R_G. At G = 1000, RG = 100 Ω is required; layout parasitics and resistor tolerance become critical, and gain error increases to ±0.5% max. The device is characterized and specified up to G = 1000, with bandwidth reduced to 350 Hz.

Does INA333AIDGKTG4 require external capacitors on the RG pins?

No, the INA333AIDGKTG4 does not require external capacitors on RG pins. However, parasitic capacitance > few pF at pins 1 and 8 degrades stability and high-frequency CMRR. Layout best practice is to minimize trace length, avoid vias, and keep RG traces short and symmetric - especially for G ≥ 100 where RG ≤ 1.01 kΩ.

Can INA333AIDGKTG4 operate from a single 1.8 V supply?

Yes, INA333AIDGKTG4 is fully specified for 1.8 V to 5.5 V single-supply operation. At 1.8 V, it maintains rail-to-rail output swing (within 50 mV of rails), 25 μV max offset (G ≥100), and 50 μA quiescent current. Input common-mode range is (V–) + 0.1 V to (V+) – 0.1 V, so with V– = 0 V and V+ = 1.8 V, usable input range is 0.1 V to 1.7 V.

How does the REF pin affect common-mode rejection in INA333AIDGKTG4?

The REF pin sets the output reference level and directly impacts CMRR. Stray resistance >15 Ω in series with REF degrades CMRR significantly - even 50 Ω can reduce 100 dB CMRR to <80 dB at 60 Hz. For optimal performance, REF must connect to a low-impedance node (e.g., ground plane or op-amp buffer); the INA333AIDGKTG4 datasheet specifies this as a hard design requirement, not a recommendation.

Is INA333AIDGKTG4 suitable for thermocouple amplification with cold-junction compensation?

Yes, INA333AIDGKTG4 is widely used for thermocouple amplification due to its 0.1 μV/°C offset drift, 50 nV/√Hz noise, and ability to resolve sub-μV signals. When paired with an external cold-junction sensor (e.g., TMP35) and reference voltage, the INA333AIDGKTG4 provides stable, low-drift gain without additional offset trimming - enabling accurate Type K/J measurements with <0.1°C uncertainty over –40°C to +125°C.