Texas Instruments LMC6484AIM

Overview

LMC6484AIM from Texas Instruments is a quad CMOS rail-to-rail input and output operational amplifier optimized for precision, low-power, single-supply operation. It delivers 82 dB CMRR, 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 signal conditioning in data acquisition and medical instrumentation.

For engineers reviewing the LMC6484AIM datasheet, LMC6484AIM pinout, LMC6484AIM application, or LMC6484AIM equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions for SOIC-14, confirmed alternatives with functional and application-level differences, and supply-chain support tailored for industrial and medical OEMs.

Technical Context

The LMC6484AIM uses a proprietary CMOS rail-to-rail input stage that extends common-mode voltage range to (V−) − 0.3 V and (V+) + 0.25 V, eliminating phase inversion beyond rails - unlike Bi-FET amplifiers. Its output stage sustains rail-to-rail swing down to 600 Ω loads while maintaining 82 dB PSRR and 74 dB CMRR at 3 V supply.

This architecture enables true linear operation across full supply range in single-supply systems: input offset voltage drift is ±1 µV/°C (−40°C to +85°C), and large-signal voltage gain exceeds 84 V/mV into 2 kΩ at 15 V, supporting high-fidelity buffering and instrumentation amplifier topologies without signal scaling.

Key Specifications

Pinout & Package

LMC6484AIM is supplied in SOIC-14 (D package), a surface-mount 14-pin small-outline integrated circuit with 1.27 mm pitch and standard JEDEC MO-002AC footprint. Thermal resistance R_θJA = 83.0 °C/W enables reliable operation at ≤85°C junction temperature with minimal heatsinking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision rail-to-rail op amp applications.

Compared with TLV2474IDR and OPA4340UA, the LMC6484AIM uniquely combines rail-to-rail input *and* output, 20 fA bias current, and 82 dB CMRR - making it irreplaceable in battery-powered, high-impedance, wide-dynamic-range measurement systems where signal integrity at supply extremes is non-negotiable.

Availability

LMC6484AIM is available at Aetrix Electronics and suitable for data acquisition systems, medical instrumentation, process analytics, and industrial control interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LMC6484AIM 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 op amp design and manufacturing excellence.

The LMC648x family was engineered specifically for high-accuracy, low-power, single-supply signal conditioning - targeting applications where rail-to-rail input range, ultra-low input current, and robust CMRR are essential, such as portable medical devices and industrial process sensors.

FAQ

What is the maximum operating supply voltage for LMC6484AIM?

The LMC6484AIM supports a recommended operating supply voltage range of 3 V to 15.5 V (V+ − V−). Absolute maximum rating is 16 V - exceeding this risks permanent damage. At 15 V, output swing remains within 1.3 V of rails into 600 Ω, and supply current per amplifier is 0.75 mA (typical). The LMC6484AIM maintains full specification compliance across this entire range, including 3 V battery operation.

Does LMC6484AIM support true rail-to-rail input beyond the supply rails?

Yes - the LMC6484AIM input common-mode voltage range extends to (V−) − 0.3 V and (V+) + 0.25 V at room temperature, enabling operation with input signals exceeding supply rails without phase inversion. This is confirmed in Section 6.3.2 of the datasheet and distinguishes it from conventional rail-to-rail op amps. However, input voltages beyond these limits require external current limiting (e.g., 10 kΩ series resistor) to avoid reliability degradation.

What is the typical input bias current of LMC6484AIM, and why does it matter?

The LMC6484AIM exhibits a typical input bias current of ±0.02 pA - among the lowest available for precision op amps. This value is critical when interfacing with ultra-high-impedance sources such as pH electrodes (≥1 GΩ), photodiodes in photovoltaic mode, or capacitive sensors, where even picoampere-level currents cause significant offset and drift. The LMC6484AIM's 20 fA bias minimizes such errors, preserving measurement fidelity without guard traces or active guarding.

Can LMC6484AIM drive 600 Ω loads while maintaining rail-to-rail output swing?

Yes - the LMC6484AIM is explicitly specified for 600 Ω loads: at 5 V supply, output swing is 4.24 V high / 0.65 V low (−40°C to +85°C); at 15 V, it is 13 V high / 1.3 V low. This capability enables direct driving of analog inputs on legacy ADCs, DACs, and analog switches without external buffers. The datasheet confirms sustained rail-to-rail performance down to 600 Ω in Section 5.6 "Voltage output swing" tables.

How does LMC6484AIM compare to TLC277 in terms of upgrade path?

The LMC6484AIM is documented as an "improved replacement for TLC272, TLC277" - offering rail-to-rail input/output (vs TLC277's limited common-mode range), 20 fA bias current (vs TLC277's ~1 pA), and 82 dB CMRR (vs TLC277's ~70 dB). Pin compatibility is maintained in SOIC-14, enabling drop-in replacement in most designs. However, LMC6484AIM requires tighter supply decoupling due to higher PSRR sensitivity, and its rail extension demands review of input protection networks originally designed for TLC277's narrower range.