Texas Instruments INA149AMDREP

Overview

INA149AMDREP from Texas Instruments is a precision unity-gain difference amplifier designed for high common-mode voltage measurement in defense, aerospace, and medical systems. It supports ±275 V common-mode input range, delivers 84 dB minimum CMRR over –55°C to +125°C, and features 500 kHz bandwidth with 5 V/µs slew rate - enabling accurate current sensing in high-voltage motor controls and battery monitoring.

For engineers reviewing the INA149AMDREP datasheet, INA149AMDREP pinout, INA149AMDREP application, or INA149AMDREP equivalent, key selection criteria include guaranteed military-temperature operation (–55°C to +125°C), ±500 V input protection, laser-trimmed resistor network for stable gain error (±0.047% FSR), and SOIC-8 package compatibility with INA117/INA148 footprints.

Technical Context

The INA149AMDREP integrates a precision op amp with a monolithic thin-film resistor network, enabling differential measurement while rejecting common-mode signals up to ±275 V. Its input stage uses precision-laser-trimmed 380 kΩ/20 kΩ resistors to achieve 0.001% FSR nonlinearity and maintain ≥84 dB CMRR across full temperature range.

It operates from ±2.0 V to ±18 V supplies, delivers ±13.5 V output swing on ±15-V rails, and includes diode-clamped REFA/REFB pins rated for ±500 V common-mode/differential transients - eliminating need for external protection in high-reliability power monitoring.

Key Specifications

Pinout & Package

INA149AMDREP is housed in an SOIC-8 (D) package with exposed pad not present; thermal resistance θ_JA = 110°C/W on JEDEC-standard high-K board. Pinout matches industry-standard difference amplifier layout for drop-in replacement of INA117 and INA148.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high common-mode voltage difference amplifier applications.

Compared with INA148IDR and AD8479ARZ, INA149AMDREP uniquely balances military-temperature reliability, ±275 V operation, 500 kHz bandwidth, and dual-reference flexibility - making it optimal for high-integrity power conversion and battery safety monitoring where all three attributes are concurrently required.

Availability

INA149AMDREP is available at Aetrix Electronics and suitable for high-voltage current sensing, battery cell voltage monitoring, and motor control applications requiring stable component supply under extended temperature and long-life program requirements.

Supply support for INA149AMDREP 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 emphasis on reliability, precision, and long-term product support.

INA149AMDREP belongs to TI's precision difference amplifier product line, engineered specifically for high common-mode voltage measurement in safety-critical and mission-reliability applications including defense avionics, medical imaging power supplies, and electric vehicle battery management.

FAQ

What is the guaranteed common-mode voltage range for INA149AMDREP over its full operating temperature range?

The INA149AMDREP guarantees ±275 V common-mode input range from –55°C to +125°C. This specification is validated per SBOS608A test conditions and applies to DC operation with V_S ≥ ±10 V. At lower supply voltages (e.g., ±5 V), the usable common-mode range reduces to –20 V to +25 V, as confirmed in the "ELECTRICAL CHARACTERISTICS: V+ = 5 V and V– = 0 V" section of the datasheet.

Does INA149AMDREP require external components to achieve specified CMRR performance?

Yes - INA149AMDREP requires low-impedance signal sources (<75 Ω) on both +IN and –IN pins and <4 Ω series resistance on REFA/REFB pins to maintain ≥84 dB CMRR. Exceeding these impedances degrades CMRR significantly (e.g., 75 Ω on input drops CMRR from 100 dB to 74 dB). No external gain-setting resistors are needed for unity-gain operation.

Can INA149AMDREP be used in single-supply configurations, and what are the output swing limitations?

Yes, INA149AMDREP supports single-supply operation (e.g., V+ = 5 V, V– = 0 V), with output swing limited to 1.7 V to 3.4 V under those conditions. The device maintains 100 dB CMRR at DC and 90 dB at 1 kHz in this configuration. Output drive capability remains stable up to 10 nF capacitive load, matching dual-supply behavior.

How does the REFA and REFB pin functionality affect the transfer function of INA149AMDREP?

The full transfer function of INA149AMDREP is V_OUT = (+IN) – (–IN) + 20 × REFA – 19 × REFB. This allows precise offset adjustment: applying 100 mV to REFA adds +2 V to output, while same voltage on REFB subtracts 1.9 V. Both pins are diode-clamped to supply rails and tolerate ±500 V transients - enabling robust reference biasing in noisy environments.

Is INA149AMDREP pin-compatible with other Texas Instruments difference amplifiers?

Yes, INA149AMDREP is pin-compatible with INA117 and INA148 in the SOIC-8 (D) package. It shares identical pinout (REFB, –IN, +IN, V–, REFA, VOUT, V+, NC), allowing direct replacement. However, INA149AMDREP improves upon both predecessors with higher CMRR (84 dB vs. 74 dB), wider common-mode range (±275 V vs. ±200 V), and enhanced temperature stability.