Texas Instruments INA271SHKQ

Overview

INA271SHKQ from Texas Instruments is a high-temperature, voltage-output current-shunt monitor designed for unidirectional measurement in extreme environments. It features a –16V to +80V common-mode input range, 20V/V fixed gain, 130kHz bandwidth, and operates from +2.7V to +18V supply across –55°C to +210°C. It is used in down-hole drilling instrumentation where precision current sensing must survive sustained high junction temperatures.

For engineers reviewing the INA271SHKQ datasheet, INA271SHKQ pinout, INA271SHKQ application, or INA271SHKQ equivalent, key selection criteria include its extended temperature qualification (–55°C to +210°C), guaranteed 78dB CMRR at high VCM, ±10mV max offset, 100μV/°C offset drift, and CFP-8 HKQ ceramic flatpack packaging with no internal connection on Pin 7.

Technical Context

The INA271SHKQ employs dual-op-amp front-end architecture to sustain operation across –16V to +80V common-mode voltages independent of supply rail. Its 20V/V transfer function is implemented via laser-trimmed thin-film resistors, enabling accurate shunt voltage-to-output conversion without external gain-setting components.

It integrates a preamplifier output (PRE OUT, Pin 3) with 96kΩ output impedance and a unity-gain buffer input (BUF IN, Pin 4), enabling configurable single-pole or Sallen-Key filtering. The device draws ≤1600μA quiescent current and supports stable operation up to 210°C junction temperature with controlled electromigration life derating.

Key Specifications

Pinout & Package

INA271SHKQ is housed in an 8-pin Ceramic Flatpack (CFP) package with HKQ footprint, hermetically sealed for high-reliability operation. Pin 7 is NC (no internal connection). The package uses gold metallization and is rated for MSL N/A (non-moisture-sensitive).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar current-shunt monitor applications.

Compared with INA271SHKQ, INA271SHKJ offers identical performance in a mechanically distinct CFP package, while INA270AHD trades temperature capability and precision for lower cost in less demanding environments-making INA271SHKQ the sole option for validated 210°C operation with sub-10mV offset.

Availability

INA271SHKQ is available at Aetrix Electronics and suitable for down-hole drilling instrumentation, aerospace actuator monitoring, high-temperature motor control, and industrial battery management systems requiring stable component supply across extended temperature lifecycles.

Supply support for INA271SHKQ 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, embedded processing, and high-reliability ICs, with decades of heritage in precision signal conditioning and high-temperature product development.

The INA271-HT product line was engineered specifically for extreme-environment current sensing, targeting applications where conventional monitors fail due to thermal stress, voltage transients, or long-term reliability requirements.

FAQ

What is the maximum junction temperature specification for INA271SHKQ?

The INA271SHKQ is fully specified and production-tested for continuous operation at +210°C junction temperature. Its electromigration life derating chart (Figure 1) confirms 10-year operational life at 105°C junction, with accelerated degradation models validated up to 210°C. This makes INA271SHKQ one of few current monitors qualified for sustained ultra-high-temperature deployment, unlike standard-grade variants such as INA270AHD.

Does INA271SHKQ support bidirectional current sensing?

No, INA271SHKQ is a unidirectional current-shunt monitor optimized for positive current flow only. Its transfer function and internal architecture assume V_IN+ ≥ V_IN−, and it does not provide symmetric output swing for negative differential inputs. For bidirectional measurement, TI recommends the INA282 or INA286 families, which feature rail-to-rail output and symmetric offset specifications-neither of which applies to INA271SHKQ.

Can INA271SHKQ operate with a 3.3V supply?

Yes, INA271SHKQ operates from +2.7V to +18V, so a 3.3V supply is fully supported. At 3.3V, its output swing is limited to approximately 0.003V above GND and (V+) – 0.13V = 3.17V, with full accuracy maintained across the –55°C to +210°C range. Quiescent current remains ≤1600μA, making it compatible with low-power telemetry interfaces when paired with appropriate ADCs.

What is the purpose of Pin 7 (NC) on INA271SHKQ?

Pin 7 on INA271SHKQ is designated NC (no internal connection) and contains no bond wire or silicon connection. It must be left unconnected on the PCB-no trace, pad, or solder mask opening is required. This pin exists solely for mechanical symmetry in the CFP-8 HKQ package and has zero electrical function. Connecting it risks unintended coupling or contamination in hermetic sealing processes.

How does the PRE OUT / BUF IN interface simplify filtering in INA271SHKQ?

The PRE OUT (Pin 3) provides a high-impedance, 96kΩ buffered preamplifier output, while BUF IN (Pin 4) accepts that signal into a unity-gain buffer. This separation enables passive RC low-pass filtering between them-e.g., a 1nF capacitor to GND on PRE OUT yields ~1.66kHz cutoff-without loading the gain stage. This architecture avoids external op amps and preserves accuracy, a capability explicitly documented in Figure 17a/b of the INA271SHKQ datasheet.