LM393ADT

Active In Stock · 24-48h Dispatch

STMicroelectronics · Analog & Data Acquisition

STMicroelectronics LM393ADT dual general-purpose comparator, 8-SOIC surface-mount package, 2V to 36V single supply, 18mA output sink, 0.1µA input bias, 0°C to 70°C.

STMicroelectronics LM393ADT — Analog & Data Acquisition
RoHS Compliant · Lead-Free EIA-481 Standard Tape & Reel

Key Specifications

All 12 Specs
Package / Case
8-SOIC
Mounting Type
Surface Mount
Operating Temp
0°C~70°C
Packaging Format
Tape & Reel (TR); Cut Tape (CT)
Supply Voltage
2V ~ 36V, ±1V ~ 18V
Type
General Purpose
Output type
CMOS, DTL, ECL, MOS, Open-Collector, TTL
Voltage - input offset
2mV @ 30V
ALT
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Full Technical Specifications

12 Parameters
LM393ADT specifications
Parameter / AttributeSpecification / Value
TypeGeneral Purpose
Output typeCMOS, DTL, ECL, MOS, Open-Collector, TTL
MountingSurface Mount
Voltage - input offset2mV @ 30V
Voltage - supply, single (Dual (±))2V ~ 36V, ±1V ~ 18V
Output current18mA @ 5V
Current - quiescent2.5mA
Current - input bias0.1µA @ 5V
Operating temperature0°C~70°C
PackageTape & Reel (TR); Cut Tape (CT)
Case8-SOIC (0.154\", 3.90mm Width)
Number of elements2
100% Footprint Match · Solder-Ready (No PCB Redesign Needed)

Need Stock or a Drop-in Second-Source for LM393ADT?

Package: DIP-8 / SOIC-8 · Pin-compatible replacements with immediate Shenzhen spot stock

Footprint Match 99%
Supply Chain & Allocation Reality:

The LM393 is the dual voltage comparator behind every threshold, window and alarm decision in instruments and industrial boards: 2V to 36V supply, ground-sensing inputs, open-collector outputs, and an 8-pin map that is identical to the LM358 op-amp pinout - the twin arrangement that makes socket-level swaps look possible and schematic-level swaps dangerous. Its family tree covers the whole repair shelf: temperature-grade siblings (LM193 / LM293 / LM2903 automotive) and the quad LM339 for four-channel boards. The two failure stories this page exists for: a comparator that stopped switching because the pull-up is missing, and an op-amp fitted into a comparator socket that saturates slowly and cannot wire-OR.

Verified Pin-Compatible Replacements (3 verified alternatives)

LM2903 TI / onsemi / STMicroelectronics DIP-8 / SOIC-8
100% Drop-in (Zero Code Change)
Availability & Target Pricing:

The Automotive Temperature Twin

Shenzhen Spot Stock (24-48h Dispatch)

Electrical & Core Specs:

The same dual comparator qualified across the wider temperature band - the 2903 grade covers the -40C class - electrically the same part, graded for industrial extremes and under-hood duty.

Same 2V to 36V envelope; open-collector outputs with the same sink capability.

Compatibility & Drop-In Notes: Direction rule: substituting upward in temperature grade is free; a commercial LM393 in a cold-environment board ends in drift complaints, not immediate failure - read the board temperature spec first.
Package & Solder Footprint: Identical 8-pin footprint.
Shenzhen Warehouse Stock & MOQ: Stocked across the grades; one quote covers the ladder.
LM339 TI / onsemi / STMicroelectronics DIP-14 / SOIC-14
Functional Equivalent
Availability & Target Pricing:

The Quad Sibling - Four Channels, Different Body

Shenzhen Spot Stock (24-48h Dispatch)

Electrical & Core Specs:

The same comparator core four times over in a 14-pin body: two channels wired in parallel match an LM393 function (open-collector outputs tie together happily), and the spare channels sit unused.

Same 2V to 36V class; the quad body moves the supply to pin 3 and ground to pin 12 - never the dual arrangement.

Compatibility & Drop-In Notes: The pinouts do not migrate: the LM393 carries V+ on 8 and GND on 4, the LM339 on 3 and 12. Both families are open-collector and microsecond-class - the differences are the body and the channel count.
Package & Solder Footprint: 14-pin; not a socket substitute for the 8-pin dual.
Shenzhen Warehouse Stock & MOQ: Stocked; the quad covers stranded-channel repairs.
LM358 TI / onsemi / STMicroelectronics DIP-8 / SOIC-8
Functional Equivalent
Availability & Target Pricing:

The Pinout Twin - A Different Species in the Socket

Shenzhen Spot Stock (24-48h Dispatch)

Electrical & Core Specs:

The op-amp that fits every hole: identical 8-pin map, push-pull output, internally compensated for linear duty - and functionally not a comparator.

3V to 32V, push-pull output limited to the supply rails.

Compatibility & Drop-In Notes: This card exists because the sockets are indistinguishable: if a repaired threshold circuit now responds late or drifts, check whether an op-amp replaced the comparator - and the reverse, a comparator in a feedback amplifier has no frequency compensation and oscillates.
Package & Solder Footprint: Same 8-pin footprint; only the schematic knows the difference.
Shenzhen Warehouse Stock & MOQ: Universal stock; match the device class to the circuit function.
Buyer & Quality Checklist for Sourcing Alternatives
  • The 8-pin map is shared: 1 out1, 2 in1-, 3 in1+, 4 GND, 5 in2+, 6 in2-, 7 out2, 8 V+ - on both the LM393 and the LM358. Nothing about the socket distinguishes a comparator from an op-amp; the schematic does.
  • Open-collector law: the LM393 output is a switch to ground and needs a pull-up (or a load) to a rail up to about 36V regardless of supply. A comparator that measures dead after repair is most often a missing pull-up or a pull-up to the wrong rail.
  • The reverse mistake is quieter: an LM393 - uncompensated, very high gain - fitted into a feedback amplifier oscillates; an LM358 fitted into a comparator node switches late and cannot drive wired-OR logic. Both pass a quick power-on test and fail the real one.
  • Temperature grades substitute freely upward (LM2903 into an LM393 socket) and carry a slow-drift risk downward - the -40C grade exists for reasons a cold warehouse finds its own way to.
  • Where the board needs a channel count the dual cannot give, the LM339 quad is the family answer - with a different 14-pin body (V+ on 3, GND on 12) that will not fit the 8-pin socket.
  • Input common mode includes ground across this whole family, which is why it dominates single-supply divider sensing: a sensing node that can swing below ground (inductive flyback, battery reversal) needs input protection, not just a substitution.
Frequently Asked Technical Questions

Q: What is the difference between the LM393 and the LM358?

A: Same 8-pin pinout, different device class: the LM393 is a dual comparator with open-collector outputs built for threshold decisions; the LM358 is a dual op-amp with a push-pull output internally compensated for linear amplification. The sockets are identical, the functions are not.

Q: Can I use an LM358 instead of an LM393 (or the reverse)?

A: Only after checking the circuit function. An op-amp in a comparator socket needs its output behavior - pull-up, wired-OR, speed - re-examined; a comparator in a linear feedback circuit has no compensation and will oscillate. If the node only needs a slow threshold, the op-amp can work; if it needs open-collector drive, nothing about the op-amp will.

Q: Why is my comparator output dead after replacement?

A: The LM393 output is open-collector: without a pull-up resistor or a load to a positive rail it reads low or floating with nothing to measure. Check the pull-up first, then the supply (2V to 36V) and the reference divider.

Technical Details & Description

Supply range and input characteristics

The LM393ADT operates from a single 2V to 36V supply or dual ±1V to ±18V rails — this wide compliance means the same comparator works across 3.3V logic, 5V industrial, 12V automotive, and 24V panel supplies without a secondary regulator. Maximum input bias current is 0.1µA at 5V — low enough that a 10kΩ source resistor drops only 1mV, preserving threshold accuracy in high-impedance sensor interfaces like thermistor bridges or photodiode transimpedance stages. Input offset voltage is trimmed to 2mV max at 30V — for a window comparator monitoring a 0-10V analog signal, this offset contributes less than 0.02% of full-scale error, well within the guard band of most 8-bit ADC thresholds.

Output drive and logic compatibility

Typical output sink current is 18mA at 5V — enough to drive a standard LED (10-15mA), a small relay coil via a base resistor, or the input of a CMOS/TTL gate without a buffer transistor. The open-collector output stage interfaces directly with CMOS, DTL, ECL, MOS, and TTL families — a single pull-up resistor to the logic rail sets the high-level voltage, making the LM393ADT a universal level translator between sensor domains and logic families.

Package and temperature grade

Housed in an 8-SOIC (0.154-inch width, 3.90mm body) with a standard 1.27mm lead pitch — the footprint matches the JEDEC MS-012AA land pattern, which is shared by thousands of op-amps and comparators, so a board spin for a second-source is rarely needed.

Lifecycle and sourcing posture

ROHS3 compliant — no exemption expiry risk for EU/RoHS-regulated markets.

Frequently asked questions

Is the LM393ADT a drop-in replacement for the LM393ST?

Both are STMicroelectronics dual comparators in the same LM393 family. The LM393ADT comes in an 8-SOIC package, while the LM393ST uses an 8-TSSOP package — they are not footprint-compatible without a board layout change.

What compliance documentation does STMicroelectronics provide for the LM393ADT?

The LM393ADT is ROHS3 compliant.

LM393ADT
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