Texas Instruments INA156EA/250G4

Overview

INA156EA/250G4 from Texas Instruments (formerly Burr-Brown) is a single-supply, rail-to-rail output CMOS instrumentation amplifier with fixed internal gains of 10 V/V or 50 V/V, ±5 µV/°C offset drift, 550 kHz bandwidth at G = 10, and MSOP-8 packaging. It is optimized for low-voltage sensor signal conditioning in industrial bridge and RTD measurement systems.

For engineers reviewing the INA156EA/250G4 datasheet, INA156EA/250G4 pinout, INA156EA/250G4 application, or INA156EA/250G4 equivalent, key selection considerations include its rail-to-rail output swing within 20 mV of rails, low 1 pA input bias current, –55°C to +125°C specified temperature range, and dual-gain pin-strapping capability without external resistors.

Technical Context

The INA156EA/250G4 employs a two-op-amp CMOS architecture with internal precision resistor networks to achieve fixed gains of 10 V/V (RG pins open) or 50 V/V (RG pins shorted). Its rail-to-rail output stage uses complementary common-source transistors, enabling full-swing operation into high-impedance loads up to 10 kΩ.

Input common-mode range is dynamically constrained by internal node A1's output swing and varies with gain setting and reference voltage - for G = 10, VCM is bounded by 0.9V– + 0.1VREF < VCM < 0.9V+ + 0.1VREF; for G = 50, tighter bounds apply per Figure 7 in the datasheet. The device requires a low-impedance Ref terminal connection to maintain CMRR > 65 dB.

Key Specifications

Pinout & Package

VSSOP-8 (DGK) package - 3.0 mm × 3.0 mm, 0.65 mm pitch, exposed pad optional; moisture sensitivity level MSL-2-260°C-1 year; RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD8221ARMZ and INA333AIDRGT, the INA156EA/250G4 uniquely delivers fixed 10×/50× gain without external components, rail-to-rail output, and guaranteed operation down to –55°C - making it optimal for cost-sensitive, high-volume industrial sensor modules where simplicity and ruggedness outweigh ultra-low drift or ultra-low power.

Availability

INA156EA/250G4 is available at Aetrix Electronics and suitable for industrial sensor amplifiers, medical biopotential front ends, PCMCIA data acquisition cards, and low-cost automotive instrumentation requiring stable component supply across extended temperature ranges.

Supply support for INA156EA/250G4 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 delivering analog and embedded processing solutions, with heritage in precision analog from Burr-Brown acquisition in 2000.

The INA156EA/250G4 belongs to TI's legacy instrumentation amplifier portfolio, designed specifically for low-cost, single-supply sensor signal conditioning in industrial and medical equipment where rail-to-rail output and fixed-gain simplicity are prioritized.

FAQ

What gain options does the INA156EA/250G4 support, and how are they configured?

The INA156EA/250G4 supports two fixed internal gains: 10 V/V and 50 V/V. Gain is selected by pin strapping - leaving Pins 1 and 8 open configures G = 10; shorting them together configures G = 50. No external resistors are needed for either setting, and gain error remains below ±0.4% for G = 10 and ±0.8% for G = 50 across temperature. This eliminates gain-setting component tolerance errors and layout sensitivity in the INA156EA/250G4 design.

Does the INA156EA/250G4 require an external reference voltage source, and what are the drive requirements?

Yes, the INA156EA/250G4 requires a low-impedance voltage applied to the Ref pin (Pin 5) to set the output common-mode level. The Ref terminal must be driven by a source impedance < 20 Ω to preserve CMRR > 65 dB - typically achieved using an op-amp buffer. In single-supply operation, Ref is commonly tied to VS/2; improper drive causes measurable gain shift and degraded common-mode rejection in the INA156EA/250G4.

What is the input bias current path requirement for the INA156EA/250G4, and why is it critical?

The INA156EA/250G4 has ultra-low input bias current (±1 pA typical), but both inputs require a DC return path to establish proper common-mode voltage. Without it, inputs float beyond the common-mode range and saturate. For balanced performance, use matched resistors from VIN+ and VIN– to Ref or V–; for low-impedance sources (e.g., thermocouples), a single return path suffices. This requirement is fundamental to stable operation of the INA156EA/250G4.

Can the INA156EA/250G4 drive capacitive loads, and what is the maximum recommended value?

The INA156EA/250G4 is characterized for stable operation with capacitive loads up to 100 pF, as confirmed by step-response testing and overshoot curves. Driving larger capacitive loads (e.g., >200 pF) may cause ringing or instability unless isolated with a series resistor. Its ability to directly drive CDAC-input ADCs like the ADS7818 makes the INA156EA/250G4 suitable for compact, high-speed data acquisition without external buffering.

What is the absolute maximum supply voltage rating for the INA156EA/250G4, and how does it relate to operational limits?

The absolute maximum supply voltage for the INA156EA/250G4 is 7.5 V between V+ and V–, but the device is fully specified and guaranteed only from +2.7 V to +5.5 V. Operation outside this range may yield unpredictable performance or accelerated aging. Input terminals tolerate (V–) – 0.5 V to (V+) + 0.5 V, with ESD diodes clamping excursions beyond that - all defined in the Absolute Maximum Ratings table for the INA156EA/250G4.