Texas Instruments INA101KU/1K

Overview

INA101KU/1K from Texas Instruments (formerly Burr-Brown) is a high-accuracy instrumentation amplifier optimized for low-level signal conditioning in precision measurement systems. It delivers 0.25 µV/°C max input offset drift, 25 µV max initial offset voltage, 0.002% max nonlinearity, and 13 nV/√Hz input voltage noise density at 1 kHz - enabling stable amplification of microvolt-level signals from strain gages and thermocouples.

For engineers reviewing the INA101KU/1K datasheet, INA101KU/1K pinout, INA101KU/1K application, or INA101KU/1K equivalent, key selection criteria include its SOL-16 surface-mount package, ±15 V supply operation, gain range of 1–1000 set by external RG resistor, 106 dB CMR at 60 Hz (G = 10), and guaranteed 0°C to +70°C commercial temperature range.

Technical Context

The INA101KU/1K integrates three precision op amps and laser-trimmed metal-film resistors on a single monolithic IC to achieve high common-mode rejection and low gain error. Its architecture uses dual feedback paths with internal 10 kΩ and 20 kΩ resistors to implement the gain equation G = 1 + 40 kΩ/RG, where RG is an external precision resistor.

It features separate Gain Sense and Gain Set terminals on the SOL-16 package to minimize wiring-resistance-induced gain error at high gains (≥100), and includes dedicated Offset Adjust pins for input offset trimming - though laser trimming ensures most applications require no external adjustment.

Key Specifications

Pinout & Package

SOL-16 surface-mount package (SOIC-DW, 16-pin), RoHS-compliant, moisture sensitivity level 3 (260°C peak reflow, 168-hour floor life).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD620ARZ and INA128UA, the INA101KU/1K provides superior gain stability at high settings due to its dual Gain Set/Gain Sense architecture and lowest offset drift (0.25 µV/°C), making it optimal for metrology-grade fixed-installation systems requiring long-term calibration stability.

Availability

INA101KU/1K is available at Aetrix Electronics and suitable for strain gage amplification, thermocouple conditioning, and RTD measurement applications requiring stable component supply across industrial OEM production cycles.

Supply support for INA101KU/1K 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 acquired Burr-Brown in 2000 and maintains its precision analog portfolio, including legacy high-accuracy signal-conditioning ICs designed for metrology, test equipment, and industrial sensing.

The INA101 product line was engineered for ultra-stable, low-drift amplification of microvolt-level transducer outputs - targeting applications where laser-trimmed resistor matching and thermal symmetry are critical to measurement integrity.

FAQ

What is the maximum gain achievable with INA101KU/1K, and how is it set?

The INA101KU/1K supports a gain range of 1 to 1000 V/V, set by a single external resistor RG using the equation G = 1 + 40 kΩ/RG. For G = 1000, RG = 40.04 Ω; for G = 1, RG is open-circuit. The SOL-16 package provides dedicated Gain Set and Gain Sense pins to minimize errors from PCB trace resistance, especially critical above G = 100. This architecture ensures the INA101KU/1K maintains specified accuracy even with non-ideal layout conditions.

Does INA101KU/1K require external offset adjustment in typical applications?

No - the INA101KU/1K is laser-trimmed for ≤25 µV initial input offset and ≤0.25 µV/°C drift, so most applications (especially at G < 100) operate without external trimming. Offset adjustment is only recommended for high-gain configurations (G ≥ 100) with both inputs grounded, using the dedicated Offset Adjust pins (1 and 2). Improper use - such as nulling system-level offsets - can increase drift by 0.3 µV/°C per 100 µV adjusted, so the INA101KU/1K's factory calibration is preferred for long-term stability.

What is the significance of the Common pin (Pin 6) in INA101KU/1K circuit design?

The Common pin (Pin 6) on the INA101KU/1K defines the output reference potential and must be connected to a low-impedance ground (≤0.1 Ω series resistance) to maintain >106 dB common-mode rejection at 60 Hz. Unlike conventional op-amp references, this node directly impacts CMR performance - any impedance here degrades rejection proportionally. In PCB layout, the INA101KU/1K Common pin should tie directly to a solid ground plane with minimal trace length, and never routed through connectors or shared return paths with noisy digital circuits.

Can INA101KU/1K operate from ±5 V supplies, and what performance trade-offs apply?

Yes - the INA101KU/1K operates from ±5 V to ±20 V supplies per absolute maximum ratings. At ±5 V, output swing reduces to ±3.5 V (typ), and small-signal bandwidth drops ~30% versus ±15 V (e.g., 1.75 kHz at G = 1000). Quiescent current remains stable (~7 mA), but CMR degrades slightly (by ~3 dB at 60 Hz) due to reduced internal headroom. The INA101KU/1K retains all key specs - including offset drift and nonlinearity - making it viable for low-power portable instrumentation where supply constraints exist.

Is INA101KU/1K pin-compatible with other packages in the INA101 family?

No - the INA101KU/1K uses a 16-pin SOL-16 (SOIC-DW) footprint, while the DIP variants (INA101HP) use 14-pin PDIP and TO-100 versions use 10-pin metal cans. Pin functions differ significantly: the SOL-16 includes two Gain Sense and two Gain Set pins (4-terminal RG interface), whereas DIP packages have only one Gain Set and no Gain Sense. Therefore, the INA101KU/1K requires unique PCB layout and cannot be substituted without redesign - its pinout is not interchangeable with other INA101 package options.