Texas Instruments CD74HC237M

Overview

CD74HC237M from Texas Instruments is a high-speed CMOS 3-to-8 line decoder/demultiplexer with address latches, featuring active-high 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 where output state retention and cascading capability are required.

For engineers reviewing the CD74HC237M datasheet, CD74HC237M pinout, CD74HC237M application, or CD74HC237M equivalent, this device is selected for systems requiring low-power, latchable 1-of-8 decoding with TTL-compatible drive strength, wide supply voltage tolerance, and robust noise immunity (NIL/NIH = 30% of VCC at 5V).

Technical Context

The CD74HC237M implements a 3-bit binary address latch followed by an active-high 1-of-8 decoder. Latch Enable (LE) controls transparency vs. latched operation: when LE is low, outputs follow A0–A2 inputs; when LE is high, outputs hold the last decoded state. Two independent Output Enable inputs (OE0 and OE1) allow flexible demultiplexing - one serves as data input while the other remains asserted.

Its HC logic family ensures CMOS-level power efficiency with TTL-equivalent speed: propagation delay is specified down to 13ns (typical, 5V/15pF), output transition time is ≤19ns (typical, 4.5V), and fanout supports up to 10 LSTTL loads over full temperature range. Input thresholds are rail-proportional (VIH = 3.15V min, VIL = 1.35V max at VCC = 4.5V), enabling reliable interfacing across mixed-voltage systems.

Key Specifications

Pinout & Package

CD74HC237M is supplied in a 16-pin SOIC (Small Outline Integrated Circuit) package, 3.9mm body width, 1.75mm height, with standard 1.27mm pitch. Pin 1 is located at the top-left corner with notch or beveled edge marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD74HC137M, the CD74HC237M avoids signal inversion in enable paths; compared with CD74HCT237M, it supports wider supply voltage flexibility (2V–6V) at the cost of reduced TTL input compatibility - critical for battery-powered or multi-rail embedded systems.

Availability

CD74HC237M is available at Aetrix Electronics and suitable for memory address decoding, industrial I/O expansion, automotive body control, and test equipment signal routing requiring stable component supply across extended temperature ranges.

Supply support for CD74HC237M 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 components.

The CD74HC237M belongs to TI's High-Speed CMOS Logic family, designed specifically for low-power, latchable decoding and demultiplexing in industrial, automotive, and aerospace systems demanding wide temperature operation and rail-to-rail voltage flexibility.

FAQ

What is the function of the Latch Enable (LE) pin on the CD74HC237M?

The Latch Enable (LE) pin on the CD74HC237M is an active-high control that determines whether the device operates in transparent or latched mode. When LE is low, outputs Y0–Y7 follow A0–A2 inputs in real time; when LE is high, the outputs retain the last decoded state regardless of subsequent address changes. This feature is essential for stable chip select generation in microcontroller-based systems where address bus timing may be asynchronous. The CD74HC237M truth table explicitly defines this behavior across all operating conditions.

Does the CD74HC237M support 3.3V operation?

Yes, the CD74HC237M fully supports 3.3V operation as part of its 2V to 6V supply range. At VCC = 3.3V, input thresholds scale proportionally (VIH ≈ 1.0V min, VIL ≈ 0.45V max), and propagation delay increases moderately (typically ~20ns at CL = 15pF). All DC specifications - including output drive (±25mA), leakage (<±1µA), and noise margins - remain valid across the entire voltage range. The CD74HC237M is widely deployed in mixed-voltage 3.3V/5V systems without level-shifting circuitry.

How does the CD74HC237M differ from the CD74HC137M?

The CD74HC237M and CD74HC137M share identical pinout, package, and functional block diagram but differ exclusively in output polarity: CD74HC237M drives selected outputs HIGH (active-high), whereas CD74HC137M drives them LOW (active-low). This distinction affects downstream logic polarity requirements - for example, CD74HC237M directly enables active-high chip selects, while CD74HC137M suits active-low reset or enable lines. Both parts maintain identical timing, power, and temperature specs, making them drop-in replacements except for output logic sense.

Can the CD74HC237M be used as a demultiplexer?

Yes, the CD74HC237M can be configured as a 1-line-to-8-line demultiplexer by using one Output Enable (e.g., OE0) as the data input and holding the other (OE1) low, while applying 3-bit select codes to A0–A2. In this mode, the selected Yx output replicates the OE0 logic state, effectively routing a single input signal to one of eight destinations. The CD74HC237M datasheet confirms this usage in the Description section and provides truth table entries validating demux operation under both latched and transparent LE conditions.

What is the maximum output current per pin for the CD74HC237M?

The CD74HC237M supports a maximum DC output source or sink current of ±25mA per output pin (Y0–Y7), as specified in the Absolute Maximum Ratings table. This rating applies across the full operating temperature range (–55°C to +125°C) and allows direct driving of LEDs, small relays, or TTL inputs without external buffers. However, total device current (ICC) must remain within ±50mA, so simultaneous high-current drive on multiple outputs requires careful thermal and power budgeting. The CD74HC237M datasheet lists these limits unambiguously in Section 4.