Texas Instruments LM3900D

Overview

LM3900D from Texas Instruments is a quadruple Norton (current-differencing) operational amplifier optimized for single-supply operation across 4.5 V to 32 V, delivering 2.5 MHz unity-gain bandwidth, ±6 mA short-circuit output current, and rail-to-rail output swing up to 29.5 V at 30 V supply - widely used in industrial sensor signal conditioning and automotive body control modules.

For engineers reviewing the LM3900D datasheet, LM3900D pinout, LM3900D application, or LM3900D equivalent, this page delivers verified electrical parameters, thermal limits, SOIC-14 package mapping, and functional alternatives validated for single-supply current-mode amplification tasks requiring input bias current below 200 nA and operation from 0°C to 70°C.

Technical Context

The LM3900D implements a current-input, current-mirror-based architecture where differential input current flows through an external feedback resistor to generate output voltage - distinct from voltage-mode op-amps. Its inverting input accepts current signals directly, with mirror gain tightly controlled between 0.9–1.1 µA/µA over temperature.

It features internal frequency compensation, output short-circuit protection with unlimited duration at ≤25°C, and clamp transistors limiting negative input swing to –0.3 V. Input bias current remains stable at ≤200 nA (typical) and ≤300 nA (full range), while supply current stays near 6.2–10 mA across all four amplifiers regardless of supply voltage magnitude.

Key Specifications

Pinout & Package

LM3900D is housed in a 14-pin SOIC (Small Outline Integrated Circuit) package per JEDEC MS-012, with 1.27 mm pitch, 8.65 mm × 3.91 mm body, and RoHS-compliant NiPdAu lead finish. Moisture Sensitivity Level is Level-1 (unlimited floor life at ≤30°C/60% RH).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar current-differencing amplifier applications.

Compared with LM2900D, LM3900D trades extended temperature capability for lower cost and qualification scope - ideal for commercial-grade systems. Compared with TLV2464IDR, LM3900D preserves native current-input operation essential for direct photodiode or 4–20 mA interface without added components.

Availability

LM3900D is available at Aetrix Electronics and suitable for industrial sensor interface, automotive body control, and power supply monitoring applications requiring stable component supply, long-lifecycle support, and RoHS-compliant SOIC packaging.

Supply support for LM3900D 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 U.S.-based semiconductor company founded in 1930, specializing in analog ICs, embedded processors, and high-reliability components for industrial, automotive, and communications markets.

The LM3900D belongs to TI's legacy analog amplifier product line, designed specifically for robust, low-cost current-mode signal processing in single-supply environments - emphasizing simplicity, fault tolerance, and wide-voltage operation over precision voltage amplification.

FAQ

What is the maximum supply voltage rating for LM3900D?

The absolute maximum supply voltage for LM3900D is 36 V, but the recommended operating range is 4.5 V to 32 V under normal conditions. Exceeding 32 V risks exceeding internal power dissipation limits, especially at elevated temperatures. The device's continuous total dissipation at 70°C is 736 mW in SOIC-14 packaging, which constrains safe operation at higher voltages with significant output loading. Always refer to the Dissipation Rating Table in the SLOS059 datasheet for derating guidance.

Does LM3900D support dual-supply operation?

Yes, LM3900D supports dual-supply operation with VCC+ ranging from 2.2 V to 16 V and VCC– from –2.2 V to –16 V. However, its Norton architecture performs best with proper common-mode current biasing on the non-inverting inputs - typically achieved using matched resistors to mid-rail or dedicated current sources. Unlike standard voltage-mode op-amps, it does not require symmetrical rails; asymmetric configurations (e.g., +15 V / –5 V) are electrically valid if input currents remain within specified limits.

What is the input voltage limit below ground for LM3900D?

The LM3900D includes internal clamp transistors that limit the inverting input voltage to approximately –0.3 V below ground. This protects the input stage during negative transients but does not eliminate the need for external current limiting: negative input currents must be restricted to ≤ –1 mA (at 25°C) or ≤ –100 µA (at high temperature) to prevent output degradation or mirror saturation. Exceeding these values causes the output voltage to drop abnormally and may reduce mirror gain accuracy.

Can LM3900D drive capacitive loads directly?

LM3900D can drive moderate capacitive loads (≤100 pF) without instability, as confirmed by slew rate measurements (0.5 V/µs low-to-high, 20 V/µs high-to-low at ±15 V). For larger capacitive loads (e.g., >500 pF), external isolation resistance (≥100 Ω) is required in series with the output to maintain phase margin. Layout sensitivity is higher than voltage-mode op-amps due to potential feedback coupling from output to non-inverting input - keep output traces short and avoid parallel routing near sensitive inputs.

Is LM3900D pin-compatible with LM3900N?

Yes, LM3900D (SOIC-14) and LM3900N (PDIP-14) share identical pin numbering, pin functions, and electrical specifications - only the package differs. Both use the same "LM3900" device marking and operate over 0°C to 70°C. No PCB redesign is needed when upgrading from PDIP to SOIC; however, thermal performance differs (SOIC-14 has higher thermal resistance), so power dissipation must be re-evaluated in high-current applications.