Texas Instruments LMC6022IM

Overview

LMC6022IM from Texas Instruments is a low-power CMOS dual operational amplifier designed for high-impedance signal conditioning in single- or dual-supply systems. It delivers 120 dB voltage gain, 40 fA input bias current, 0.11 V/μs slew rate, and rail-to-rail input common-mode range extending to V−, enabling precision buffering in medical instrumentation and long-term integrators.

For engineers reviewing the LMC6022IM datasheet, LMC6022IM pinout, LMC6022IM application, or LMC6022IM equivalent, key selection criteria include ultra-low input bias current for photodiode preamplification, micropower operation at 86 μA per amplifier, guaranteed performance from −40°C to +85°C, and SOIC-8 packaging compatible with standard PCB assembly processes.

Technical Context

The LMC6022IM uses a compound integrator-based output stage without a traditional unity-gain buffer, enabling rail-to-rail output swing while maintaining stability into 5 kΩ loads. Its topology includes dual feed-forward compensation (Cf and Cff) and a push-pull output stage optimized for both sourcing and sinking current.

This architecture yields asymmetric large-signal voltage gain: ≥100 V/mV when sourcing into 100 kΩ, ≥50 V/mV when sinking into 5 kΩ, and supports stable operation with capacitive loads up to ~100 pF when combined with series output resistance and feedback capacitance.

Key Specifications

Pinout & Package

LMC6022IM is housed in an 8-pin SOIC (D) package with 1.27 mm pitch, 3.91 mm body width, and 1.75 mm max height, compliant with JEDEC MS-012 AA and RoHS requirements.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual CMOS op-amp applications.

Compared with TLC27L2CD and OPA2313IDR, the LMC6022IM uniquely balances femtoamp input bias, micropower consumption, and V−-referenced input range-making it irreplaceable in long-duration, high-impedance electrochemical and optical sensing where leakage-induced drift must be minimized.

Availability

LMC6022IM is available at Aetrix Electronics and suitable for medical instrumentation, industrial sensor interfaces, and portable environmental monitoring requiring stable component supply across extended production lifecycles.

Supply support for LMC6022IM 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 expertise in precision op-amps and low-power signal chain solutions.

The LMC6022IM belongs to TI's legacy LMC6000 family of micropower CMOS op-amps, engineered specifically for ultra-high-impedance, low-leakage applications including electrochemical sensors, photodiode amplifiers, and precision integrators.

FAQ

What is the maximum capacitive load the LMC6022IM can drive without oscillation?

The LMC6022IM remains stable with capacitive loads up to approximately 100 pF when configured as a unity-gain follower. For larger loads, TI recommends adding a 50–100 Ω series resistor at the output and a 5–10 pF capacitor from inverting input to output. This technique restores phase margin without degrading low-frequency performance in applications like sample-and-hold circuits using the LMC6022IM.

Does the LMC6022IM support true single-supply operation with input signals at ground potential?

Yes, the LMC6022IM features an input common-mode voltage range that includes V−, allowing its inputs to operate at 0 V when powered from a single +5 V supply. This capability makes the LMC6022IM ideal for ground-referenced sensor interfaces such as thermocouple amplifiers or bridge transducer conditioners where the LMC6022IM eliminates the need for negative supply rails or level-shifting circuitry.

How does the LMC6022IM achieve rail-to-rail output swing despite using a CMOS process?

The LMC6022IM achieves rail-to-rail output swing through a custom compound integrator output stage-not a conventional unity-gain buffer. This design directly sources and sinks current from the integrator's push-pull node, enabling output voltages within 0.09 V of V− and 0.4 V of V+ into 5 kΩ. This architecture is integral to the LMC6022IM's ability to deliver full dynamic range in low-voltage battery-powered systems.

Can the LMC6022IM be used in a Howland current pump configuration?

Yes, the LMC6022IM is explicitly validated for Howland current pump topologies, as shown in Figure 30d of its datasheet. Its ultra-low input bias current (40 fA) and high CMRR (63 dB min) ensure accurate current source compliance and minimal error from input leakage-critical for precision current sources in bioimpedance analyzers or programmable load circuits using the LMC6022IM.

What PCB layout practices are essential to preserve the LMC6022IM's 40 fA input bias current specification?

To preserve the LMC6022IM's 40 fA input bias current, TI mandates guard rings surrounding both inputs and connected passive components, routed on both top and bottom PCB layers and driven at the same potential as the inputs. Surface contamination or humidity-induced leakage across 10¹² Ω traces can degrade performance by 100×; air-wiring the input pins is recommended for ultimate leakage control in ultra-high-impedance LMC6022IM applications.