Texas Instruments CD74HC237PWG4

Overview

CD74HC237PWG4 from Texas Instruments is a high-speed CMOS 3-to-8 line decoder/demultiplexer with address latches, configured for active-high output selection. It features three binary select inputs (A0–A2), latch enable (LE), two output enables (OE0/OE1), 16-pin TSSOP package, and operates from 2V to 6V. Used in memory address decoding and data routing where latched address isolation and demultiplexing are required.

For engineers reviewing the CD74HC237PWG4 datasheet, CD74HC237PWG4 pinout, CD74HC237PWG4 application, or CD74HC237PWG4 equivalent, this page delivers verified functional behavior, truth-table–confirmed active-high decoding, latch timing constraints, thermal performance at -55°C to +125°C, and real-world cascading capability via dual OE inputs.

Technical Context

The CD74HC237PWG4 implements a 3-bit 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; when LE is high, outputs hold the last decoded state. Two independent Output Enable inputs (OE0 and OE1) support hierarchical cascading and flexible demultiplexing - one OE serves as data input while the other remains asserted.

Its HC logic family ensures CMOS-level power efficiency (ICC ≤ 160 µA over full temperature range) with TTL-compatible speed: typical propagation delay is 13 ns at VCC = 5 V, CL = 15 pF, TA = 25°C. Input thresholds meet 30% noise immunity (NIL/NIH) at 5 V, and it drives up to 10 LSTTL loads across -55°C to +125°C.

Key Specifications

Pinout & Package

CD74HC237PWG4 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 gull-wing leads and pin 1 index marking. Thermal resistance θJA = 108°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD74HC237PWG4, CD74HC137PW provides identical timing and packaging but inverted output polarity - requiring redesign of enable logic - while SN74LV138APWR sacrifices latching and drive capability for lower static power, making it unsuitable for address-stable bus arbitration or industrial noise margins.

Availability

CD74HC237PWG4 is available at Aetrix Electronics and suitable for memory address decoding, industrial I/O expansion, automated test equipment, and bus-based peripheral selection requiring stable component supply across extended temperature ranges.

Supply support for CD74HC237PWG4 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 delivering analog, embedded processing, and logic solutions with emphasis on reliability, longevity, and industrial-grade qualification.

The CD74HC237PWG4 belongs to TI's High-Speed CMOS Logic family, designed specifically for robust address decoding and data routing in harsh-environment systems where latch stability, wide voltage operation, and extended temperature tolerance are mandatory.

FAQ

What is the key functional difference between CD74HC237PWG4 and CD74HC137PW?

The CD74HC237PWG4 provides active-high decoded outputs (Yx = HIGH when selected), whereas CD74HC137PW delivers active-low outputs (Yx = LOW when selected). Both share identical pinout, supply range (2V–6V), latch enable (LE), dual output enables (OE0/OE1), and timing specs. This polarity difference dictates whether external inversion is needed to interface with downstream enable inputs expecting HIGH or LOW assertion - a critical layout and logic design consideration for CD74HC237PWG4 integration.

Does CD74HC237PWG4 support latched operation, and how is it controlled?

Yes, CD74HC237PWG4 supports latched operation via its Latch Enable (LE) input (Pin 12). When LE is HIGH, the internal 3-bit address latch holds the last A0–A2 values, freezing outputs regardless of subsequent address changes. When LE is LOW, outputs track A0–A2 in real time (transparent mode). This behavior is confirmed in the 'HC237 truth table and enables glitch-free chip selection during multiplexed bus cycles - a core capability distinguishing CD74HC237PWG4 from non-latching alternatives like SN74LV138APWR.

What is the maximum recommended operating temperature for CD74HC237PWG4, and is it qualified for extended-range use?

CD74HC237PWG4 is fully specified and qualified for operation from -55°C to +125°C, as documented in its Absolute Maximum Ratings and Operating Conditions tables. This extended temperature range is validated across all electrical parameters including propagation delay, input thresholds, and output drive strength. The TSSOP package (PW) used in CD74HC237PWG4 maintains this rating, making it suitable for under-hood automotive modules, downhole oilfield tools, and industrial motor drives where ambient temperatures exceed standard commercial limits.

Can CD74HC237PWG4 be used as a demultiplexer, and how is data routed?

Yes, CD74HC237PWG4 functions as a 1-of-8 demultiplexer. To route data: apply the 3-bit channel address to A0–A2, hold one Output Enable (e.g., OE1) LOW (active), and feed the serial data stream into the other Output Enable (e.g., OE0). The selected Yx output will mirror the data input while all others remain LOW. This configuration leverages the device's dual OE architecture - a feature explicitly described in the datasheet's "Demultiplexing Function" section - and requires no external logic, enabling compact, low-latency signal distribution in CD74HC237PWG4-based designs.

What are the supply voltage requirements and noise immunity specifications for CD74HC237PWG4?

CD74HC237PWG4 operates from 2 V to 6 V DC on VCC (Pin 16), with full functionality guaranteed across this range. At VCC = 5 V, it delivers 30% noise immunity on both inputs: Noise Immunity Low (NIL) = 30% of VCC and Noise Immunity High (NIH) = 30% of VCC. This means VIH(min) = 3.5 V and VIL(max) = 1.5 V - significantly exceeding standard TTL thresholds. These values are measured and guaranteed per the DC Electrical Specifications table, ensuring reliable operation in electrically noisy industrial settings without additional filtering for CD74HC237PWG4.