STMicroelectronics LM393ST

Overview

LM393ST from STMicroelectronics is a dual low-voltage comparator IC designed for single-supply operation from 2 V to 36 V (or ±1 V to ±18 V), featuring ±1 mV typical input offset voltage, 20 nA typical input bias current, and 0.45 mA supply current per comparator at 5 V. It supports TTL/DTL/ECL/MOS/CMOS logic interfaces and operates with input common-mode range extending to ground-enabling direct sensing of signals referenced to system ground in battery-powered and industrial control applications.

For engineers reviewing the LM393ST datasheet, LM393ST pinout, LM393ST application, or LM393ST equivalent, key selection criteria include its rail-to-rail differential input capability, 80 mV typical output saturation voltage at 4 mA sink, wide temperature range (0 °C to 70 °C), MiniSO8 package compatibility, and ESD robustness (HBM 2 kV for LM393W variant).

Technical Context

The LM393ST implements two independent PNP-input comparators with open-collector outputs, enabling wired-OR logic and flexible level translation. Its input stage allows common-mode voltage down to ground on single supply, eliminating need for level-shifting circuitry in sensor interface designs.

It delivers 1.3 μs typical response time with 100 mV input step and 5 mV overdrive, and supports differential input voltages up to the full supply rail-critical for high-noise industrial signal conditioning where input transients exceed V_CC.

Key Specifications

Pinout & Package

LM393ST is supplied in MiniSO8 package (3.0 mm × 4.9 mm, 0.65 mm pitch), with exposed pad optional for thermal enhancement. Pin 1 is Out1, Pin 2 is In1−, Pin 3 is In1+, Pin 4 is V_CC− (GND for single supply), Pin 5 is In2+, Pin 6 is In2−, Pin 7 is Out2, Pin 8 is V_CC+.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM393DT and LM393WDT, the LM393ST offers identical comparator performance in a 30% smaller MiniSO8 footprint-reducing PCB area while maintaining compatibility with standard pick-and-place equipment and reflow profiles.

Availability

LM393ST is available at Aetrix Electronics and suitable for industrial control systems, battery management units, and sensor interface modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LM393ST 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, delivering intelligent power, analog, MEMS, and microcontroller solutions for automotive, industrial, and consumer markets.

The LM393 series belongs to ST's precision analog comparators product line, engineered for robust performance in cost-sensitive, high-volume applications where ground-sensing capability and low quiescent power are essential.

FAQ

Can LM393ST operate from a 3.3 V supply?

Yes, LM393ST supports single-supply operation from 2 V to 36 V. At 3.3 V, it maintains full functionality: input common-mode range includes ground, output saturation voltage remains ≤400 mV at 4 mA sink, and propagation delay increases only marginally to ~1.8 μs-verified per DS0443 Rev 17 Table 3 and Figure 7.

Does LM393ST require external pull-up resistors on its outputs?

Yes-both outputs are open-collector and must be pulled up to a valid logic high voltage (e.g., 3.3 V or 5 V). Typical values range from 4.7 kΩ to 10 kΩ; lower values improve rise time but increase static current. No internal pull-ups exist, and leaving outputs unconnected results in undefined logic states.

What is the maximum sink current per output of LM393ST?

The absolute maximum sink current is 20 mA, but the recommended operating limit is 18 mA (per Table 3, Isink = 6–18 mA). Sustained operation above 10 mA requires attention to thermal dissipation-MiniSO8 R_thJA is 190 °C/W, so 10 mA at 5 V drop yields ~100 mW power dissipation and ~19 °C junction rise above ambient.

Is LM393ST pin-compatible with LM393D (tube-packaged SO8 version)?

No-LM393ST uses MiniSO8 (3.0 mm × 4.9 mm, 0.65 mm pitch), while LM393D uses SO8 (4.9 mm × 6.0 mm, 1.27 mm pitch). Pin numbering and functions match (1=Out1, 2=In1−, etc.), but physical layout, pad dimensions, and thermal characteristics differ significantly-requiring separate PCB footprints and reflow profile validation.