Texas Instruments LMC6494BEM/NOPB

Overview

LMC6494BEM/NOPB from Texas Instruments (formerly National Semiconductor) is a quad CMOS rail-to-rail input and output operational amplifier designed for single-supply automotive sensor signal conditioning. It operates from 5V to 15V, delivers rail-to-rail output swing within 20 mV of supply rails at 100 kΩ load, features 150 fA typical input bias current, and supports −40°C to +125°C junction temperature range-enabling direct interfacing with high-impedance pressure, oxygen, and temperature sensors in engine control units.

For engineers reviewing the LMC6494BEM/NOPB datasheet, LMC6494BEM/NOPB pinout, LMC6494BEM/NOPB application, or LMC6494BEM/NOPB equivalent, key selection criteria include ultra-low input current (150 fA), guaranteed rail-to-rail input common-mode range beyond supply rails, 82 dB CMRR at 0–15 V input range, and 1.5 MHz gain-bandwidth product under 15 V supply-critical for precision DC-coupled transducer amplification in harsh-temperature environments.

Technical Context

The LMC6494BEM/NOPB employs a proprietary CMOS input stage enabling true rail-to-rail input voltage range (V− −0.25 V to V+ +0.25 V) without phase inversion, even when inputs exceed supply rails-a critical capability for unconditioned sensor outputs in automotive manifold pressure systems. Its output stage delivers rail-to-rail swing with sourcing/sinking capability up to ±30 mA and low output impedance (110 Ω sourcing / 80 Ω sinking at 5 V).

It achieves 120 dB open-loop voltage gain (RL = 100 kΩ), 82 dB CMRR over full common-mode range (0 V to 15 V), and 1.3 V/µs slew rate (15 V supply), supporting stable operation in unity-gain and low-noise non-inverting configurations while maintaining >50° phase margin into 100 pF capacitive loads when properly compensated.

Key Specifications

Pinout & Package

LMC6494BEM/NOPB is housed in a 14-pin SOIC (Small Outline Integrated Circuit) package (NS Package Number M14A), 5.0 mm × 8.65 mm body, 1.27 mm pitch, with exposed pad not present. Pin numbering follows standard SOIC convention: Pin 1 (top-left corner, marked by dot or bevel), counterclockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLC27L4CDR and OPA4340UA, LMC6494BEM/NOPB uniquely combines 150 fA input bias current, guaranteed −40°C to +125°C operation, and rail-to-rail input beyond supply rails - making it the only option among the three qualified for high-accuracy, high-temperature automotive transducer amplification without external protection circuitry.

Availability

LMC6494BEM/NOPB is available at Aetrix Electronics and suitable for automotive sensor signal conditioning, industrial pressure monitoring, and battery management system temperature front-ends requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LMC6494BEM/NOPB 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 National Semiconductor in 2011 and maintains full technical and manufacturing continuity for legacy precision analog products including the LMC649x family.

The LMC6494BEM/NOPB belongs to TI's legacy high-precision CMOS op-amp portfolio, originally engineered for automotive and industrial sensor interface applications demanding ultra-low input current, rail-to-rail operation, and extended temperature reliability.

FAQ

What is the maximum operating temperature for LMC6494BEM/NOPB?

The LMC6494BEM/NOPB is specified for junction temperatures from −40°C to +125°C, with all electrical parameters guaranteed across this full range. This makes LMC6494BEM/NOPB suitable for under-hood automotive applications where ambient temperatures can exceed 105°C, provided proper PCB thermal design maintains junction temperature within limits.

Does LMC6494BEM/NOPB support true rail-to-rail input beyond the supply rails?

Yes, LMC6494BEM/NOPB guarantees an input common-mode voltage range from V− −0.25 V to V+ +0.25 V at room temperature, and V− −0.25 V to V+ +0.25 V for CMRR ≥50 dB across temperature. This allows LMC6494BEM/NOPB to accept input signals exceeding both supply rails without phase inversion-critical for unbuffered transducer outputs in automotive systems.

What is the typical input bias current of LMC6494BEM/NOPB and why does it matter?

The typical input bias current of LMC6494BEM/NOPB is 150 fA, with a maximum of 200 pA across temperature. This ultra-low value enables direct interfacing with high-impedance sources such as strain gauge bridges, oxygen sensors, and photodiodes without introducing measurable offset errors-making LMC6494BEM/NOPB essential for precision sensor signal chains.

Can LMC6494BEM/NOPB drive capacitive loads directly?

LMC6494BEM/NOPB is not optimized for direct capacitive load driving; its phase margin degrades with >100 pF loads. For stable operation, use a series resistor (e.g., 100 Ω) between output and capacitive load, or add a small isolation capacitor in the feedback path as described in the datasheet Application Hints section. This ensures LMC6494BEM/NOPB maintains >50° phase margin in anti-aliasing filter or peak detector designs.

What package type is used for LMC6494BEM/NOPB?

LMC6494BEM/NOPB uses a 14-pin SOIC (Small Outline Integrated Circuit) package, designated NS Package Number M14A, with 1.27 mm lead pitch, 5.0 mm × 8.65 mm body dimensions, and no exposed thermal pad. This surface-mount package supports automated assembly and provides reliable thermal performance in automotive-grade PCB layouts.