STMicroelectronics LM393DT

Overview

LM393DT 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 rail-to-rail input common-mode range including ground. It delivers TTL/CMOS-compatible open-collector outputs with 80 mV typical output saturation voltage at 4 mA sink current, widely used in voltage monitoring, zero-crossing detection, and level-shifting circuits in industrial control and power management systems.

For engineers reviewing the LM393DT datasheet, LM393DT pinout, LM393DT application, or LM393DT equivalent, key selection criteria include input offset voltage stability over temperature, supply current independence from VCC, ESD robustness (HBM 2 kV for LM393W variant), and compatibility with legacy 5 V/12 V/24 V logic interfaces without level shifters.

Technical Context

The LM393DT implements two independent PNP-input comparators with rail-to-rail input common-mode range down to ground-enabling direct sensing of signals referenced to system ground under single-supply conditions. Its differential input voltage range equals the full supply voltage (±36 V), supporting inputs exceeding VCC+ by up to 1 V when the opposite input remains within common-mode limits.

Output stage uses open-collector NPN transistors capable of sinking ≥6 mA while maintaining ≤400 mV saturation voltage across temperature. Internal architecture avoids phase reversal and supports direct interfacing with TTL, CMOS, ECL, and MOS logic families without pull-up resistors beyond those required by load capacitance and speed requirements.

Key Specifications

Pinout & Package

LM393DT is supplied in SO8 package (Small Outline Integrated Circuit, 150 mil width), RoHS-compliant and ECOPACK® certified. Pin 1 is marked by notch or dot; exposed pad is not present in SO8 variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM393DR and TLV3702IDR, LM393DT provides optimal balance of wide supply range (2–36 V), proven reliability in industrial environments, and cost-effective SO8 packaging - making it the preferred choice for general-purpose voltage monitoring where automotive qualification or nanowatt operation is unnecessary.

Availability

LM393DT is available at Aetrix Electronics and suitable for overvoltage protection, zero-crossing detection, temperature threshold monitoring, and LED driver enable control requiring stable component supply across long-lifecycle industrial programs.

Supply support for LM393DT 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, designing and manufacturing silicon solutions for smart driving, power management, sensing, connectivity, and microcontrollers.

LM393DT belongs to ST's legacy analog comparators product line, engineered for robustness, wide supply adaptability, and seamless integration into cost-sensitive industrial and consumer control systems since the 1980s.

FAQ

Can LM393DT operate from a 3.3 V supply?

Yes, LM393DT supports single-supply operation from 2 V to 36 V, including 3.3 V. At 3.3 V, input common-mode range extends from 0 V to 1.8 V, and output saturation voltage remains ≤400 mV at 4 mA sink current. Logic compatibility requires pull-up to 3.3 V, and propagation delay increases slightly versus 5 V operation.

Does LM393DT require external hysteresis for noise immunity?

Yes - LM393DT has no internal hysteresis. For reliable switching in noisy environments (e.g., motor drive feedback), external positive feedback via resistor from output to non-inverting input is required. Typical hysteresis width is set by resistor ratio and output voltage swing; values between 10 mV and 50 mV are common for industrial signal conditioning.

What is the maximum sink current per output of LM393DT?

LM393DT outputs can sink up to 18 mA continuously (6 mA min, 18 mA max) with ≤400 mV saturation voltage at 25 °C. Derating applies above 70 °C ambient; at 100 °C junction temperature, maximum safe sink current drops to ~10 mA to maintain <1 V saturation and avoid thermal runaway.

Is LM393DT pin-compatible with LM293 or LM193?

Yes - all members of the LM193/LM293/LM393 family share identical SO8 pinout, electrical behavior, and functional block diagram. Differences lie solely in temperature grade (−55 to +125 °C for LM193, −40 to +105 °C for LM293, 0 to +70 °C for LM393DT) and minor parametric limits such as input offset voltage max.