Texas Instruments LMC6081-MDA

Overview

LMC6081-MDA from Texas Instruments is a precision single-channel CMOS operational amplifier optimized for ultra-low-input-bias-current applications including photodiode preamplification, medical instrumentation, and high-impedance transducer signal conditioning. It delivers 150 μV typical input offset voltage, 10 fA typical input bias current, rail-to-rail output swing within 20 mV of supply rails (at 2 kΩ load), and operates from 4.5 V to 15.5 V single supply.

For engineers reviewing the LMC6081-MDA datasheet, LMC6081-MDA pinout, LMC6081-MDA application, or LMC6081-MDA equivalent, this page provides verified technical context, real-world design implications of key specs, package-validated pin functions, and two confirmed alternative parts with documented functional and application-level differences.

Technical Context

The LMC6081-MDA employs a proprietary CMOS input stage enabling input common-mode range extending to V– and ultra-low 10 fA bias current at 25°C - critical for charge-integrating and high-impedance sensor interfaces. Its rail-to-rail output stage sustains 20 mV headroom at 2 kΩ load while delivering 123 dB open-loop gain and 1.3 MHz gain-bandwidth product.

Designed for single-supply operation down to 4.5 V, it maintains stable performance across –40°C to +85°C with <1 μV/°C offset drift and >75 dB PSRR (positive rail). The device features improved latch-up immunity and supports precision configurations such as instrumentation amplifiers, charge amplifiers, and sample-and-hold circuits without external compensation under standard loads.

Key Specifications

Pinout & Package

LMC6081-MDA is housed in an 8-pin SOIC (D package) with exposed pad thermal enhancement per TI's mechanical documentation. Pin 1, 5, and 8 are no-connect (NC) terminals and must remain unconnected or floating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMC6081-MDA, LMC6061IMX/NOPB trades DC precision and bandwidth for micropower operation, while OPA377AIDBVR prioritizes speed and noise performance at the expense of femtoampere-level input bias current - making LMC6081-MDA uniquely suited for picoampere-sensitivity applications like photodiode and piezoelectric charge integration.

Availability

LMC6081-MDA is available at Aetrix Electronics and suitable for medical instrumentation, environmental sensor signal chains, and portable analytical equipment requiring stable component supply with guaranteed long-term manufacturability and TI-authorized traceability.

Supply support for LMC6081-MDA 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.

The LMC608x family was engineered specifically for ultra-high-impedance, low-offset, single-supply precision signal conditioning - targeting medical diagnostics, scientific instrumentation, and industrial sensing where femtoampere input bias and rail-to-rail output are non-negotiable.

FAQ

What is the maximum operating temperature range for the LMC6081-MDA?

The LMC6081-MDA is specified for continuous operation from –40°C to +85°C junction temperature. This range is validated per TI's Recommended Operating Conditions and supported by thermal metrics including RθJA = 193°C/W for the SOIC-D package. Operation beyond +85°C risks exceeding the absolute maximum junction temperature of 150°C and may degrade offset drift and bias current performance. For LMC6081-MDA designs in thermally constrained enclosures, derating per PD = (TJ(Max) − TA)/θJA is required.

Does the LMC6081-MDA support true rail-to-rail input common-mode range?

The LMC6081-MDA supports input common-mode voltage down to V– (including ground in single-supply use), but does not extend fully to V+. Per datasheet Section 5.7, the upper limit is (V+) – 1.9 V at 25°C - meaning it cannot accept inputs within 1.9 V of the positive rail. This partial rail-to-rail input capability enables ground-referenced sensor interfaces but requires input signal scaling or clamping if near-V+ voltages are present. The LMC6081-MDA output, however, achieves true rail-to-rail swing within 20 mV of both rails under 2 kΩ load.

Can the LMC6081-MDA drive capacitive loads directly?

The LMC6081-MDA is not optimized for direct capacitive load driving: typical stability degrades with >100 pF loads due to phase margin reduction. As documented in Section 6.1.3, capacitive loads require external compensation - either a series isolation resistor (e.g., 50–100 Ω) between output and load, or a pull-up resistor to V+ conducting ≥500 μA. For LMC6081-MDA applications involving ADC input filtering or cable-driven outputs, indirect drive topologies with RC snubbers or buffer stages are recommended to maintain pulse fidelity and prevent oscillation.

What is the purpose of the NC pins (1, 5, 8) on the LMC6081-MDA?

Pins 1, 5, and 8 of the LMC6081-MDA are designated No-Connect (NC) with no internal silicon connection. They must remain electrically unconnected - neither tied to ground, supply, nor left floating in high-noise environments. TI's Pin Functions table explicitly states these pins have "no internal connection" and advises against routing traces to them. Leaving them unpopulated or isolated prevents parasitic coupling that could modulate the ultra-sensitive input stage. For LMC6081-MDA PCB layouts, NC pins should be excluded from copper pours and guard rings to avoid unintended field coupling.

How does the LMC6081-MDA compare to the dual-channel LMC6082 in terms of key specs?

The LMC6081-MDA and LMC6082 share identical electrical specifications - same 150 μV offset, 10 fA bias current, 1.3 MHz GBW, and rail-to-rail output behavior - because they belong to the same LMC608x family and use identical core die. The sole difference is channel count: LMC6081-MDA is single-channel in 8-pin SOIC, while LMC6082 integrates two independent amplifiers in the same package footprint. This makes LMC6081-MDA optimal for space-constrained single-amplifier roles (e.g., dedicated photodiode preamp), whereas LMC6082 suits dual-path signal chains (e.g., differential sensor pairs) without increasing board area.