Texas Instruments INA105AM

Overview

INA105AM from Texas Instruments is a precision unity-gain differential amplifier optimized for high-accuracy signal conditioning in harsh environments. It delivers 80–90 dB CMRR (–40°C to +125°C), ±0.01% max gain error, 500 µV max offset voltage, and operates across –55°C to +125°C. It serves as the core front-end amplifier in battery cell formation systems and industrial level transmitters where rail-to-rail common-mode input range (±20 V) and laser-trimmed resistor matching are critical.

For engineers reviewing the INA105AM datasheet, INA105AM pinout, INA105AM application, or INA105AM equivalent, this page provides verified electrical specs, thermal metrics, package mapping to TO-99 metal can, functional pin roles, real-world use cases in servo position feedback and string inverters, and two validated alternative parts with documented performance trade-offs.

Technical Context

The INA105AM integrates a precision bipolar op amp with four on-chip 25 kΩ laser-trimmed metal-film resistors-two for input division and two for feedback-to form a fixed G = 1 difference amplifier. Its internal resistor ratio matching enables stable CMRR over temperature, with TCR tracking limiting gain drift to 5 ppm/°C.

It supports dual-supply operation from ±5 V to ±18 V and features extended common-mode input range (±20 V at ±15 V supplies) via internal resistive attenuation. The device uses CSO: SHE fabrication flow, confirmed by TI's nomenclature table, and exhibits 2–3 V/µs slew rate and 1 MHz bandwidth under standard test conditions.

Key Specifications

Pinout & Package

INA105AM is packaged in an 8-pin TO-99 metal can (LMC), providing hermetic sealing and superior thermal dissipation (R_θJA = 52.3°C/W) for high-reliability analog signal chains.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA105BM, the INA105AM trades 10 µV/°C lower offset drift for identical CMRR, bandwidth, and gain error-making it optimal for cost-sensitive industrial sensing where ambient temperature variation is moderate. Against INA117P, INA105AM delivers 20 dB higher CMRR and 5× better DC accuracy, but cannot handle >±25 V inputs.

Availability

INA105AM is available at Aetrix Electronics and suitable for battery cell formation equipment, servo drive feedback systems, and level transmitter designs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for INA105AM 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 precision amplifiers and data acquisition ICs.

The INA105 product line was engineered for high-accuracy differential signal conditioning in industrial automation, test equipment, and energy infrastructure-emphasizing laser-trimmed resistor stability, wide common-mode range, and extended temperature operation.

FAQ

What is the maximum common-mode input voltage for INA105AM?

The INA105AM supports a common-mode input voltage range of ±20 V when operated with ±15 V supplies. This is achieved through internal 25 kΩ resistive attenuation before the op amp inputs. Absolute maximum input voltage without protection is ±25 V-exceeding either supply rail by 10 V-but input current must be limited to 1 mA to avoid damage. This specification is explicitly confirmed in Section 5.4 of the SBOS145B datasheet for the AM grade.

Does INA105AM require external resistors for unity-gain operation?

No, the INA105AM does not require external resistors for unity-gain difference amplifier operation. It integrates four precisely matched 25 kΩ laser-trimmed on-chip metal-film resistors configured internally to deliver exact G = 1 performance. These resistors are ratio-matched to <0.1% and track over temperature, eliminating the need for discrete precision networks. This is clearly stated in the "Description" section and Figure 3-1 of the INA105AM datasheet.

What package type is used for INA105AM?

The INA105AM is supplied in an 8-pin TO-99 metal can package (designated LMC in TI documentation), offering hermetic sealing, excellent thermal conductivity (R_θJA = 52.3°C/W), and EMI shielding. This package is distinct from the PDIP (P) and SOIC (D) variants offered for other INA105 grades. Package identification is confirmed in TI's Mechanical, Packaging, and Orderable Information section and Table 8-1 (Device Nomenclature).

How does the Sense pin (Pin 5) function in INA105AM?

The Sense pin (Pin 5) on the INA105AM connects to a 25 kΩ resistor tied to the inverting input of the internal op amp. It enables current-sensing topologies where the amplifier measures voltage drop across a shunt while maintaining rail-to-rail output compliance. When used with the Ref pin, it supports precision current-to-voltage conversion with programmable gain and offset. This functionality is detailed in Figure 7-23 ("Current Receiver With Compliance to Rails") and Section 7.3.4 of the INA105AM datasheet.

Is INA105AM pin-compatible with INA105KP or INA105KU?

No, the INA105AM is not pin-compatible with INA105KP or INA105KU. While all share the same 8-pin TO-99 (LMC), PDIP (P), or SOIC (D) footprints, the AM/BM grades use the CSO: SHE fabrication flow, whereas KP/KU grades use mixed CSO: SHE or CSO: RFB flows-resulting in differing electrical characteristics (e.g., slew rate, short-circuit current, voltage noise). TI explicitly separates them in nomenclature and specifies distinct test conditions; interchangeability is not supported.