Texas Instruments INA333SHKQ

Overview

INA333SHKQ from Texas Instruments is a micro-power, zero-drift instrumentation amplifier designed for precision signal conditioning in extreme-temperature environments. It delivers 25 μV max input offset voltage (G ≥100, 25°C), 0.2 μV/°C drift (G ≥1000), 100 dB min CMRR (G ≥10), rail-to-rail output swing, and operates from +1.8 V to +5.5 V supply. It is used in down-hole drilling sensor front-ends where high accuracy and stability at +210°C are critical.

For engineers reviewing the INA333SHKQ datasheet, INA333SHKQ pinout, INA333SHKQ application, or INA333SHKQ equivalent, key selection criteria include guaranteed performance across –55°C to +210°C, RFI-filtered inputs for noisy industrial environments, single-resistor programmable gain (G = 1 + 100 kΩ/R_G), and ultra-low quiescent current (198 μA max at +210°C).

Technical Context

The INA333SHKQ employs a 3-op-amp architecture with auto-calibration circuitry that corrects offset every 8 μs, enabling true zero-drift behavior and eliminating 1/f noise. Its internal laser-trimmed 150 kΩ feedback resistors ensure stable gain accuracy and low temperature drift without external trimming.

It integrates RFI filtering at VIN+ and VIN– pins (8 MHz corner frequency), supports single-supply operation with REF pin biasing, and features input voltage range of (V–) + 0.1 V to (V+) – 0.1 V and output swing of (V–) + 0.05 V to (V+) – 0.05 V - all specified over the full –55°C to +210°C operating range.

Key Specifications

Pinout & Package

The INA333SHKQ is housed in an HKQ package: ceramic dual-inline flatpack (DIP), 8-pin, with metal lid and ceramic base. Pin 1 is RG (gain-setting terminal), Pin 2 is VIN–, Pin 3 is VIN+, Pin 4 is NC (no connect), Pin 5 is V–, Pin 6 is REF, Pin 7 is VOUT, Pin 8 is V+.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA333SJD and INA128HT, the INA333SHKQ uniquely combines programmable gain, RFI filtering, and the lowest drift (0.2 μV/°C) across –55°C to +210°C - making it the sole option for new down-hole and aerospace designs requiring field-adjustable gain and certified EMI resilience.

Availability

INA333SHKQ is available at Aetrix Electronics and suitable for down-hole drilling, aerospace engine monitoring, and geothermal instrumentation requiring stable component supply under extreme temperature stress and long product lifecycles.

Supply support for INA333SHKQ 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 heritage in high-reliability, high-temperature IC design.

The INA333-HT product line was developed specifically for mission-critical sensing in oil & gas, aerospace, and energy infrastructure - delivering precision amplification where standard commercial or industrial ICs fail due to thermal degradation.

FAQ

What is the maximum operating temperature of the INA333SHKQ?

The INA333SHKQ is fully specified and tested over an operating temperature range of –55°C to +210°C. Its electrical characteristics, including offset voltage, drift, CMRR, and bandwidth, are guaranteed across this entire range per TI's SBOS514C datasheet. This makes the INA333SHKQ suitable for permanent installation in down-hole drilling tools and turbine engine monitoring systems.

Does the INA333SHKQ require external capacitors for stability?

No, the INA333SHKQ does not require external compensation capacitors for basic operation. However, for gains >100 in +210°C applications, TI recommends adding a 3.5 kΩ resistor in series with a 10 nF capacitor from each RG pin (Pins 1 and 8) to ground to maintain phase margin and prevent oscillation. The internal RFI filters eliminate need for external input RC networks.

Can the INA333SHKQ operate from a single 3.3-V supply?

Yes, the INA333SHKQ supports single-supply operation from +1.8 V to +5.5 V. With a 3.3-V supply, its input common-mode range is +0.1 V to +3.2 V, and output swings from +0.05 V to +3.25 V into 10 kΩ. For optimal CMRR, the REF pin must be biased to mid-supply (1.65 V) using a low-impedance source - such as a buffered divider or dedicated reference.

What is the purpose of Pin 4 (NC) on the INA333SHKQ?

Pin 4 on the INA333SHKQ is a no-connect (NC) terminal - an unbonded pad with no internal connection. It must remain electrically floating and unconnected on the PCB. No trace, solder mask opening, or thermal pad should be placed at Pin 4. This design choice maintains signal integrity and prevents parasitic coupling that could degrade CMRR or RFI rejection.

How does the RFI filtering in the INA333SHKQ improve system-level performance?

Each input (VIN+ and VIN–) of the INA333SHKQ includes an integrated passive RC filter with ~8 MHz cutoff frequency. This suppresses RF rectification - a failure mode where high-frequency EMI (e.g., from VFDs or radio transmitters) demodulates into DC offset errors. In down-hole telemetry, this prevents false temperature readings during mud-pulse transmission bursts, directly improving measurement reliability without added external components.