Texas Instruments CD74HC237EG4

Overview

CD74HC237EG4 from Texas Instruments is a high-speed CMOS 3-to-8 line decoder/demultiplexer with address latches, designed for memory address decoding and data routing in industrial control and instrumentation systems. It features active-high outputs, dual output enables (OE0/OE1), latch enable (LE), three binary select inputs (A0–A2), and operates from 2V to 6V with typical propagation delay of 13ns at VCC = 5V, CL = 15pF, TA = 25°C.

For engineers reviewing the CD74HC237EG4 datasheet, CD74HC237EG4 pinout, CD74HC237EG4 application, or CD74HC237EG4 equivalent, this page delivers verified functional behavior, truth-table–confirmed output polarity, latch timing constraints, thermal performance across –55°C to +125°C, and validated alternatives for legacy design refresh or supply continuity planning.

Technical Context

The CD74HC237EG4 implements a 3-bit binary address latch followed by an active-high 1-of-8 decoder. Inputs A0–A2 are latched on LE high, isolating outputs from subsequent address changes until LE transitions low - enabling transparent operation or static selection. OE0 and OE1 provide independent gating: one serves as data input during demultiplexing while the other remains asserted.

Unlike the CD74HC137 (active-low output), the CD74HC237EG4 asserts the selected Yx output high while all others remain low. Its HC logic family ensures CMOS-level noise immunity (NIL/NIH = 30% of VCC at 5V), fanout of 10 LSTTL loads, and quiescent current ≤160 µA over full temperature range.

Key Specifications

Pinout & Package

CD74HC237EG4 is supplied in a 16-lead plastic dual in-line package (PDIP), with 0.3-inch body width and through-hole mounting. Pin 1 is located at the top-left corner, identified by a notch or dot marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD74HC237EG4, CD74HC137E requires hardware-level polarity inversion to match active-high output behavior, while SN74HC237N provides identical functionality with alternate TI branding - making it the preferred alternative for seamless replacement in production builds.

Availability

CD74HC237EG4 is available at Aetrix Electronics and suitable for industrial control systems, avionics data acquisition modules, and automotive ECU memory mapping applications requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for CD74HC237EG4 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 decades of heritage in high-reliability logic families.

The CD74HC237EG4 belongs to TI's CD74HC high-speed CMOS logic series, engineered for robust performance in harsh environments - emphasizing wide temperature operation, low power, and noise-immune digital interfacing for industrial and defense applications.

FAQ

What is the output behavior of CD74HC237EG4 when OE0 and OE1 are both high?

When both OE0 and OE1 are held high (inactive), all eight outputs (Y0–Y7) are forced low regardless of A0–A2 or LE state. This high-impedance–like disable condition ensures no unintended signal assertion on downstream circuits - a critical safety feature in fault-tolerant systems using CD74HC237EG4.

Does CD74HC237EG4 support demultiplexing, and how is it configured?

Yes, CD74HC237EG4 supports demultiplexing by using one output enable (e.g., OE0) as the data input while holding the other (OE1) low. With A0–A2 selecting Yx, the data appears at the chosen output - enabling 1-to-8 serial-to-parallel conversion without additional logic. This configuration is explicitly defined in the device truth table for CD74HC237EG4.

What is the maximum clock frequency supported by CD74HC237EG4 in address-latched mode?

The CD74HC237EG4 does not operate on a clock signal; its timing is governed by setup/hold and propagation delays. With tSU = 13ns and tH = 8ns (VCC = 4.5V), the minimum address update period is ~21ns - supporting effective address switching up to ~47MHz in latch-controlled applications using CD74HC237EG4.

Can CD74HC237EG4 operate reliably at 3.3V supply voltage?

Yes, CD74HC237EG4 is fully specified for 2V–6V operation. At VCC = 3.3V, VIH = 2.31V min and VIL = 0.99V max ensure compatibility with 3.3V microcontrollers, while propagation delay increases to ~18ns (CL = 15pF) - well within timing budgets for most embedded control applications using CD74HC237EG4.

Is CD74HC237EG4 pin-compatible with CD74HC237M or CD74HC237PWR?

No - CD74HC237EG4 uses a 16-lead PDIP package, whereas CD74HC237M is SOIC-16 and CD74HC237PWR is TSSOP-16. While functionally identical and sharing the same pin assignment order, the physical footprints differ significantly; PCB layout revision is required for substitution between CD74HC237EG4 and surface-mount variants.