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SN74HC237

Texas Instruments · 3-to-8 decoder with address latch · SOIC-16

A 3-to-8 line decoder/demultiplexer with a built-in address latch, in high-speed CMOS, SOIC-16. Like the 74HC138 it drives one of eight outputs from a 3-bit address, but here the outputs are active-high and a latch-enable pin can freeze the address so the selected output stays put after the address bus moves on. That suits multiplexed-bus systems where the address appears only briefly. Two output-enable inputs gate the whole device and allow cascading. Runs 2-6 V.

Pinout

Pin Name Type Function
1 A0 input Address select input bit 0 (LSB). Combined with A1 and A2 selects which of eight Y outputs is driven high. Latched by LE; transparent when LE is low, held on the LE low-to-high transition.
2 A1 input Address select input bit 1. Combined with A0 and A2 selects which of eight Y outputs is driven high. Latched by LE.
3 A2 input Address select input bit 2 (MSB). Combined with A0 and A1 selects which of eight Y outputs is driven high. Latched by LE.
4 LE input Latch Enable, active low. When LE is low the address inputs A0-A2 pass transparently to the decoder; on the low-to-high transition of LE the current address is latched and further changes on A0-A2 are ignored.
5 ~{OE1} input Output Enable 1, active low. Must be low together with OE0 high to enable the selected Y output. When high, all outputs are forced to their inactive state (LOW for 'HC237/'HCT237).
6 OE0 input Output Enable 0, active high. Must be high together with /OE1 low to enable the selected Y output. When low, all outputs are forced to their inactive state (LOW for 'HC237/'HCT237).
7 Y7 output Decoded output 7 (address 111). Driven HIGH when selected and both enables active; otherwise LOW. Fanout 10 LSTTL loads (standard) / 15 LSTTL loads (bus driver).
8 GND power_in Ground reference (0 V) for logic and outputs.
9 Y6 output Decoded output 6 (address 110). Driven HIGH when selected and both enables active; otherwise LOW.
10 Y5 output Decoded output 5 (address 101). Driven HIGH when selected and both enables active; otherwise LOW.
11 Y4 output Decoded output 4 (address 100). Driven HIGH when selected and both enables active; otherwise LOW.
12 Y3 output Decoded output 3 (address 011). Driven HIGH when selected and both enables active; otherwise LOW.
13 Y2 output Decoded output 2 (address 010). Driven HIGH when selected and both enables active; otherwise LOW.
14 Y1 output Decoded output 1 (address 001). Driven HIGH when selected and both enables active; otherwise LOW.
15 Y0 output Decoded output 0 (address 000). Driven HIGH when selected and both enables active; otherwise LOW.
16 VCC power_in Positive supply. HC variant: 2 V to 6 V. HCT variant: 4.5 V to 5.5 V. Decouple with a local 0.1 uF ceramic to GND close to the pin.

Key specifications

Parameter Value
Type 3-to-8 decoder/demux, latched
Address 3-bit (A0-A2), latchable
Outputs 8 active-high (Y0-Y7)
Latch LE holds the address
Enables OE0 + /OE1
Logic family HC (high-speed CMOS)
Supply voltage 2-6 V
Package SOIC-16

Ordering variants

Same part, different packaging or reel option.

  • CD74HC237M (SOIC-16, tube)
  • CD74HC237M96 (SOIC-16, tape & reel)

CAD (KiCad official)

  • Symbol: 74xx:74HC237
  • Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
  • 3D model: SOIC-16 (KiCad packages3D)

Provenance

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

  • Datasheet: Texas Instruments datasheet (27 pp, sha256 564c040df4c1b784, 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