Texas Instruments CD74HC237PW

Overview

CD74HC237PW from Texas Instruments is a high-speed CMOS 3-to-8 line decoder/demultiplexer with address latches, featuring active-high selected outputs, dual output enables (OE0, OE1), and latch enable (LE) for input isolation. It operates from 2V to 6V, delivers 13ns typical propagation delay at 5V/15pF, and supports industrial temperature range (–55°C to +125°C). It is used in memory address decoding and data routing applications requiring precise output selection and signal gating.

For engineers reviewing the CD74HC237PW datasheet, CD74HC237PW pinout, CD74HC237PW application, or CD74HC237PW equivalent, this page provides verified functional identity, TSSOP-16 package mapping, truth-table-confirmed active-high decoding behavior, latch-controlled transparency mode, and validated alternatives for legacy design continuity and supply chain resilience.

Technical Context

The CD74HC237PW implements a 3-bit binary address latch followed by an active-high 1-of-8 decoder. Its LE input controls whether A0–A2 are latched (LE = high) or transparent (LE = low), enabling synchronized address capture. Two independent output enables (OE0, OE1) allow cascading and demultiplexing - one can serve as data input while the other remains asserted.

Unlike the CD74HC137 (active-low outputs), the CD74HC237PW asserts the selected Y_n output high while all others remain low. Its HC logic family ensures CMOS-level noise immunity (NIL/NIH = 30% of V_CC at 5V), low static power, and compatibility with both LSTTL loads (10 units) and bus drivers (15 units).

Key Specifications

Pinout & Package

CD74HC237PW is housed in a 16-pin Thin Shrink Small Outline Package (TSSOP), 4.4 mm × 5.0 mm footprint, 1.2 mm max height, with 0.65 mm lead pitch. Pin 1 is marked by a dot or beveled corner at the top-left corner when viewed from the top with leads pointing downward.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 3-to-8 decoder/demultiplexer applications.

Compared with CD74HC237PW, CD74HC137PW requires logic inversion in downstream circuitry, while SN74HC237PWR offers identical behavior with enhanced manufacturability and guaranteed long-term sourcing - making it the optimal drop-in upgrade path.

Availability

CD74HC237PW is available at Aetrix Electronics and suitable for memory address decoding, industrial I/O expansion, data routing switch, and legacy bus interface logic requiring stable component supply across extended temperature ranges and multi-voltage systems.

Supply support for CD74HC237PW 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and logic solutions, with over 90 years of innovation in high-reliability IC design.

The CD74HC237PW belongs to TI's legacy HC logic family, engineered for robust, low-power, wide-supply-range decoding in industrial, aerospace, and automotive subsystems where latch synchronization and output polarity matter.

FAQ

What is the key functional difference between CD74HC237PW and CD74HC137PW?

The CD74HC237PW provides active-high decoded outputs (Y_n = high when selected), whereas CD74HC137PW provides active-low outputs (Y_n = low when selected). Both share identical pinout, latch enable (LE), and dual output enable (OE0/OE1) architecture. This polarity difference dictates whether external inversion is needed - CD74HC237PW is preferred when driving high-asserted enable lines or LED anodes directly.

Does CD74HC237PW support 3.3V operation, and what are its input voltage thresholds at that supply?

Yes, CD74HC237PW fully supports 3.3V operation as part of its 2V–6V HC logic family specification. At V_CC = 3.3V, the input high threshold (V_IH) is minimum 2.31V (70% of V_CC), and input low threshold (V_IL) is maximum 0.99V (30% of V_CC). These thresholds ensure reliable interfacing with standard 3.3V CMOS outputs without level shifting.

How does the latch enable (LE) pin affect output behavior in CD74HC237PW?

In CD74HC237PW, when LE is high, the A0–A2 inputs are latched and outputs reflect the last captured address regardless of subsequent A0–A2 changes. When LE is low, outputs become transparent - they update immediately in response to A0–A2 transitions. This dual-mode operation enables synchronized address sampling in systems with asynchronous bus timing or shared address/data multiplexing.

Can CD74HC237PW be used as a demultiplexer, and how is data routed?

Yes, CD74HC237PW functions as an 1-to-8 demultiplexer. To use it this way, hold OE1 high, apply the 3-bit channel select code to A0–A2, and feed the serial data signal into OE0. The selected Y_n output will mirror the OE0 input state (high/low), while all other outputs remain low. This configuration requires no additional logic and leverages the device's native enable architecture.

Is CD74HC237PW obsolete, and what is the recommended replacement?

CD74HC237PW is marked obsolete by Texas Instruments per official packaging addendum, but remains available through authorized distributors and Aetrix Electronics' legacy inventory. The recommended replacement is SN74HC237PWR - identical functionality, pinout, and specifications, with active production status, RoHS compliance, and full TI lifecycle support. No PCB or firmware changes are required for migration.