Texas Instruments LM393M

Overview

LM393M from Texas Instruments is a dual, low-power, precision voltage comparator IC with open-collector outputs, designed for single-supply operation from 2.0 V to 36 V or dual supplies (±1.0 V to ±18 V). It delivers ±3 mV max input offset voltage, 0.4 mA supply current at 5 V, 25 nA input bias current, and supports ground-sensing input common-mode range - enabling use in battery-powered voltage monitoring, industrial threshold detection, and logic-level interfacing.

For engineers reviewing the LM393M datasheet, LM393M pinout, LM393M application, or LM393M equivalent, key selection considerations include its rail-to-rail input capability down to ground, TTL/CMOS-compatible output stage, low quiescent current suitable for portable systems, and SOIC-8 packaging for standard PCB assembly.

Technical Context

The LM393M integrates two independent comparators with PNP differential input stages, enabling input common-mode voltage range that includes ground even under single-supply operation. Its open-collector NPN output transistors support wired-OR configurations and flexible pull-up voltage selection up to 36 V.

It operates across 0°C to +70°C ambient temperature, with guaranteed electrical performance at 5 V and 36 V supply voltages. Input offset voltage drift is minimized via matched transistor design, and response time is specified at 1.3 μs (typical) for 100 mV input step with 5 mV overdrive.

Key Specifications

Pinout & Package

LM393M is housed in an 8-pin SOIC package (4.90 mm × 3.91 mm body size), optimized for automated surface-mount assembly and thermal performance in industrial PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM393DR, LM393M offers identical functionality in tube packaging for prototyping and low-volume builds; compared with TLV3702IDR, LM393M provides superior supply voltage flexibility (up to 36 V) and tighter offset (±3 mV vs. ±15 mV), making it suitable for industrial and automotive voltage-monitoring applications where precision and wide operating range are mandatory.

Availability

LM393M is available at Aetrix Electronics and suitable for battery-powered instrumentation, industrial control panels, and automotive subsystems requiring stable component supply across long product lifecycles.

Supply support for LM393M 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 experience in precision signal conditioning and power-efficient IC design.

The LM393M belongs to TI's legacy precision comparator family, engineered for reliability in industrial, automotive, and consumer applications where robustness, wide supply range, and ground-sensing capability are essential design requirements.

FAQ

What is the maximum supply voltage rating for LM393M?

The LM393M supports a maximum supply voltage of 36 V for single-supply operation or ±18 V for dual-supply configurations. This rating is absolute - exceeding 36 V may cause permanent damage. The device maintains stable 0.4 mA supply current across the full 2.0–36 V range, making LM393M suitable for 24 V industrial systems and automotive battery monitoring without external regulation.

Does LM393M support true ground-referenced input operation?

Yes, LM393M guarantees input common-mode voltage range from 0 V to (V+ − 1.5 V), allowing both inputs to operate at ground potential even under single-supply conditions. This is enabled by its PNP input stage architecture. For example, with V+ = 5 V, inputs can swing from 0 V to 3.5 V - enabling direct connection to shunt-based current sensors or battery cathodes without level-shifting circuitry. LM393M achieves this without requiring negative supply rails.

Can LM393M outputs drive TTL or CMOS logic directly?

Yes, LM393M outputs are open-collector and fully compatible with TTL, DTL, ECL, MOS, and CMOS logic families. When paired with an appropriate pull-up resistor (e.g., 10 kΩ to 5 V), LM393M delivers logic HIGH levels matching the pull-up voltage and sinks ≥6 mA to assert logic LOW. Its 250 mV saturation voltage at 4 mA ensures solid LOW-state margins for 5 V TTL and 3.3 V CMOS inputs. No additional buffering is required for standard logic interfacing.

What is the typical response time of LM393M, and how does it vary with overdrive?

LM393M exhibits a typical response time of 1.3 μs for a 100 mV input step with 5 mV overdrive. With larger overdrive (e.g., 1 V), propagation delay improves to ~300 ns, as confirmed in TI's typical characteristics curves. This behavior stems from internal gain-stage saturation dynamics. Designers should account for this dependency when implementing high-speed pulse detection or oscillator circuits - LM393M is optimized for medium-speed applications (< 100 kHz), not RF or high-frequency timing.

Is LM393M pin-compatible with other dual comparators like LM2903 or LM293?

Yes, LM393M shares identical pinout, electrical specifications, and SOIC-8 package dimensions with LM2903 and LM293. All three devices use the same 8-pin configuration: OUTA, –INA, +INA, GND, +INB, –INB, OUTB, V+. However, their guaranteed operating temperature ranges differ - LM393M is rated for 0°C to +70°C, LM2903 for –40°C to +85°C, and LM293 for –25°C to +85°C - so thermal validation is required before substitution in extended-temperature environments.