Four independent voltage comparators in one SOIC-14, the quad sibling of the dual LM393. Each compares its two inputs and drives an open-collector output low when the minus input is above the plus input, so outputs wire-OR together and level-shift with a single pull-up resistor. The inputs work down to the negative rail, and it runs from a single 2 to 36 V supply or a split supply, which makes it easy to build level detectors, zero-crossing detectors, oscillators, and simple ADCs. Outputs need an external pull-up to the logic rail.

Pinout

Pin	Name	Type	Function
1	1OUT	output	Open-collector output of comparator 1. Requires an external pull-up resistor to VCC. Sink current up to 20 mA.
2	2OUT	output	Open-collector output of comparator 2. Requires external pull-up to VCC.
3	VCC	power_in	Positive supply. 2 V to 36 V (LM339) or up to 38 V (LM339B). Single-supply operation supported.
4	2IN-	input	Inverting (negative) input of comparator 2. Common-mode range includes ground.
5	2IN+	input	Non-inverting (positive) input of comparator 2. Common-mode range includes ground.
6	1IN-	input	Inverting (negative) input of comparator 1. Common-mode range includes ground.
7	1IN+	input	Non-inverting (positive) input of comparator 1. Common-mode range includes ground.
8	3IN-	input	Inverting (negative) input of comparator 3. Common-mode range includes ground.
9	3IN+	input	Non-inverting (positive) input of comparator 3. Common-mode range includes ground.
10	4IN-	input	Inverting (negative) input of comparator 4. Common-mode range includes ground.
11	4IN+	input	Non-inverting (positive) input of comparator 4. Common-mode range includes ground.
12	GND	power_in	Negative supply / ground reference. Tied to system ground in single-supply operation.
13	4OUT	output	Open-collector output of comparator 4. Requires external pull-up to VCC.
14	3OUT	output	Open-collector output of comparator 3. Requires external pull-up to VCC.

Key specifications

Parameter	Value
Type	Quad differential comparator
Comparators	4 independent
Output	open-collector (needs pull-up)
Input range	down to negative rail
Supply	2-36 V single or ±1-18 V split
Response time	~1.3 µs
Offset voltage	±2 mV typ
Package	SOIC-14

Ordering variants

Same part, different packaging or reel option.

LM339D (SOIC-14, tube)
LM339DR (SOIC-14, tape & reel)

CAD (KiCad official)

Symbol: Comparator:LM339
Footprint: Package_SO:SOIC-14_3.9x8.7mm_P1.27mm
3D model: SOIC-14 (KiCad packages3D)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Texas Instruments datasheet (54 pp, sha256 2a488cbc06c3e6c4, retrieved 2026-08-17, tier: manufacturer)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF