Texas Instruments LM393D

Overview

LM393D from Texas Instruments is a dual voltage comparator IC designed for single-supply operation across 2 V to 36 V, featuring ±0.37 mV typical input offset voltage, 200 µA per comparator quiescent current, and 1 µs propagation delay. It serves as a precision threshold detector in power supply monitoring, motor control feedback, and industrial sensor interfaces.

For engineers reviewing the LM393D datasheet, LM393D pinout, LM393D application, or LM393D equivalent, key selection criteria include its rail-to-rail input common-mode range (down to ground), open-collector TTL/CMOS/MOS-compatible outputs, and guaranteed operation over 0°C to 70°C ambient temperature.

Technical Context

The LM393D implements two independent high-gain comparators with internal ESD clamps enabling 2 kV HBM robustness. Its input stage supports differential input voltages up to ±38 V and common-mode inputs extending to VCC – 2 V while maintaining correct output states even when one input exceeds the valid common-mode range.

Each comparator features an open-collector output capable of sinking up to 21 mA at 5 V supply, with low-level output voltage of 400 mV max at 4 mA sink current. Quiescent current remains stable across supply voltage (5–36 V) and temperature (0°C to 70°C), ensuring predictable power budgeting in battery- and line-powered systems.

Key Specifications

Pinout & Package

LM393D is packaged in an 8-pin SOIC (Small Outline Integrated Circuit) with body size 4.90 mm × 3.91 mm, optimized for automated assembly and thermal performance in compact PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual comparator applications.

Compared with LM393DR and LM2903DT, the LM393D delivers optimal balance of precision (±0.37 mV offset), commercial-grade reliability, and SOIC-8 compatibility - making it ideal for cost-sensitive, space-constrained designs where 0°C–70°C operation suffices.

Availability

LM393D is available at Aetrix Electronics and suitable for vacuum robot control, server PSU monitoring, and cordless power tool battery management requiring stable component supply, long-term BOM continuity, and traceable sourcing.

Supply support for LM393D 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 delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The LM393D belongs to TI's industry-standard dual comparator family, engineered for robust, low-cost threshold detection in commercial power management, sensor conditioning, and control logic applications.

FAQ

What is the maximum supply voltage rating for LM393D?

The LM393D supports a maximum supply voltage of 36 V, verified per Absolute Maximum Ratings in the official Texas Instruments datasheet (SLCS005AH). This exceeds legacy LM393 versions (30 V), enabling direct interface with 24 V industrial buses and 32 V telecom supplies without external regulation. Operation above 36 V risks permanent device damage.

Does LM393D support rail-to-rail input operation?

Yes, the LM393D supports rail-to-rail input common-mode voltage from ground (0 V) up to VCC − 2 V, as confirmed in Section 5.5 of the datasheet. This allows direct connection of ground-referenced sensors and simplifies design by eliminating level-shifters. Note that inputs may safely exceed this range up to VCC without damage, though only one input needs to remain within the valid common-mode window for correct output behavior.

What is the typical input offset voltage of LM393D and how does it affect accuracy?

The LM393D has a typical input offset voltage of ±0.37 mV, with a maximum of ±4 mV over temperature (0°C to 70°C). This low offset enables precise threshold detection-for example, distinguishing a 5 mV sensor signal change from noise-without calibration. In contrast, standard LM393 variants specify ±9 mV max, making LM393D preferable for applications demanding sub-10 mV resolution.

Can LM393D drive a 5 V logic input directly?

Yes, the LM393D's open-collector outputs are compatible with TTL, CMOS, and MOS logic families. When paired with a 5 V pull-up resistor (e.g., 4.7 kΩ), the output sinks current to produce a solid logic-low (<400 mV at 4 mA), and floats to VCC for logic-high. No level-shifting is needed, and the 21 mA sink capability ensures robust drive strength even with capacitive loads.

Is LM393D pin-compatible with older LM393 variants?

Yes, the LM393D is a drop-in replacement for LM393, LM293, and LM2903 in SOIC-8 packages, as explicitly stated in the "B-version is drop-in replacement" feature list and Family Comparison Table. Pin assignments, electrical behavior, and footprint match exactly-no PCB redesign or schematic changes are required when upgrading from legacy versions to LM393D.