Texas Instruments LMC6484IM

Overview

LMC6484IM from Texas Instruments is a quad CMOS rail-to-rail input and output operational amplifier designed for precision signal conditioning in low-voltage, single-supply systems. It delivers 82 dB CMRR, ultra-low 20 fA input bias current, rail-to-rail output swing within 20 mV of supply rails (at 100 kΩ load), and specified performance at 3 V, 5 V, and 15 V supplies - enabling high-accuracy data acquisition and sensor interfacing in battery-powered medical and industrial equipment.

For engineers reviewing the LMC6484IM datasheet, LMC6484IM pinout, LMC6484IM application, or LMC6484IM equivalent, key selection criteria include its guaranteed rail-to-rail input common-mode range (extending 300 mV beyond rails), 0.75 mA per amplifier supply current at 5 V, ±0.75 mV max input offset voltage (LMC648xAI grade), 1.3 V/µs slew rate, and compatibility with 600 Ω loads - all critical for low-distortion, wide-dynamic-range analog front-ends.

Technical Context

The LMC6484IM employs a proprietary CMOS input stage that enables true rail-to-rail input operation without phase inversion, even when inputs exceed supply rails by up to 300 mV. Its output stage sustains rail-to-rail swing down to 600 Ω loads while maintaining 82 dB PSRR and CMRR across –40°C to +85°C.

This architecture supports both single-supply (3–15.5 V) and split-supply operation, with input common-mode voltage range specified from (V–) – 0.3 V to (V+) + 0.3 V and output swing as tight as 0.1 V above V– and 0.18 V below V+ at 5 V/2 kΩ - making it suitable for direct ADC buffering and high-CMRR instrumentation amplifiers.

Key Specifications

Pinout & Package

LMC6484IM is housed in a 14-pin SOIC (D package) with exposed pad thermal enhancement. Pin functions are fully defined per TI SNOS674J Rev. September 2024.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMC6484IMX, the LMC6484IM offers identical performance in tube packaging for flexibility, while TLV2464CDR sacrifices 7 dB CMRR and 50× higher input bias to gain 0.3 V/µs slew - making LMC6484IM the sole choice for sub-1 µV offset-critical pH/gas sensing and 12-bit DAQ.

Availability

LMC6484IM is available at Aetrix Electronics and suitable for data acquisition systems, patient monitors, and process analytics equipment requiring stable component supply, long-term obsolescence management, and traceable sourcing for medical and industrial certifications.

Supply support for LMC6484IM 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 over 50 years of op amp innovation and broad automotive, industrial, and personal electronics portfolio.

The LMC648x family was engineered specifically for precision rail-to-rail signal conditioning in low-power, single-supply applications - targeting medical instrumentation, portable test gear, and industrial sensor interfaces where input bias, CMRR, and output swing define system resolution.

FAQ

What is the maximum operating supply voltage for the LMC6484IM?

The LMC6484IM supports a recommended operating supply voltage range of 3 V to 15.5 V, with absolute maximum ratings up to 16 V. Operation at 15.5 V is validated across –40°C to +85°C junction temperature, enabling use in industrial 12 V and telecom 15 V systems without derating. Exceeding 16 V risks permanent damage per TI SNOS674J Section 5.1.

Does the LMC6484IM support true rail-to-rail input beyond the supply rails?

Yes, the LMC6484IM features a rail-to-rail input stage with common-mode voltage range extending 300 mV beyond both V+ and V– rails at room temperature. This allows input signals to exceed supplies without phase inversion - confirmed in Figure 6-2 of the datasheet - though input offset voltage may degrade slightly near rail extremes.

What is the typical input bias current of the LMC6484IM, and why does it matter?

The LMC6484IM exhibits a typical input bias current of 20 fA, with a maximum of ±4 pA over temperature. This ultra-low value prevents loading errors in high-impedance sensor circuits (e.g., pH electrodes >1 GΩ), ensuring accurate DC signal transmission and eliminating drift caused by bias current flowing through source impedances.

Can the LMC6484IM drive a 600 Ω load while maintaining rail-to-rail output swing?

Yes, the LMC6484IM is explicitly specified for 600 Ω loads: at 5 V supply, it delivers 0.3 V to 4.7 V swing (0.65 V to 4.24 V over temperature); at 15 V, it achieves 0.5 V to 14.1 V swing. This capability is verified in Table 5.6 and enables direct interface to legacy 600 Ω instrumentation inputs without external buffers.

Is the LMC6484IM pin-compatible with the TLC277 or TLC279?

No, the LMC6484IM is not pin-compatible with TLC277 (dual) or TLC279 (quad). While the LMC6484IM serves as an improved functional replacement per TI documentation, it uses a 14-pin SOIC layout (D package) distinct from TLC279's 14-pin PDIP pinout - requiring PCB redesign. The LMC6484IM's pin mapping is defined in Table 4-2 of SNOS674J.