Texas Instruments CD74HC237PWT

Overview

CD74HC237PWT 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. 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. Typical propagation delay is 13ns at VCC = 5V, CL = 15pF, TA = 25°C.

For engineers reviewing the CD74HC237PWT datasheet, CD74HC237PWT pinout, CD74HC237PWT application, or CD74HC237PWT equivalent, this device supports transparent/latched operation, cascading via OE inputs, and demultiplexing with one enable used as data input - critical for industrial control logic, FPGA I/O expansion, and embedded system address management.

Technical Context

The CD74HC237PWT implements a 3-bit latch followed by a 1-of-8 decoder, where LE controls latching of A0–A2 inputs: low enables transparency, high latches the address. Output selection is determined by the latched address, with Y0–Y7 asserted high per truth table. Two independent output enables (OE0, OE1) allow hierarchical enable control - OE1 must be low and OE0 high for normal decode operation.

It belongs to the HC family (not HCT), supporting 2V–6V supply with CMOS-level input thresholds (VIH = 1.5V min at VCC = 2V; VIL = 0.5V max), high noise immunity (NIL/NIH = 30% of VCC), and fanout of 10 LSTTL loads. Propagation delays are balanced across rising/falling edges, and power dissipation capacitance is 23pF (CL = 15pF, VCC = 5V).

Key Specifications

Pinout & Package

TSSOP-16 package (PW), 4.4mm × 5.0mm body, 0.65mm pitch, 1.2mm max height, RoHS-compliant NiPdAu lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar decoder/demultiplexer applications.

Compared with CD74HC137PWT, the CD74HC237PWT eliminates external inversion for high-asserted outputs, while SN74HC237PWR offers identical performance with enhanced supply chain traceability and lifecycle support.

Availability

CD74HC237PWT is available at Aetrix Electronics and suitable for industrial PLCs, automotive body controllers, FPGA peripheral interfaces, and automated test equipment requiring stable component supply across extended temperature ranges.

Supply support for CD74HC237PWT 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 connectivity solutions with emphasis on reliability, longevity, and industrial-grade qualification.

The CD74HC237PWT belongs to TI's legacy HC logic family, engineered for robust, low-power, high-speed decoding in mission-critical embedded systems where latch synchronization and wide voltage operation are essential.

FAQ

What is the key functional difference between CD74HC237PWT and CD74HC137PWT?

The CD74HC237PWT provides active-high decoded outputs (Y0–Y7 go high for selected address), whereas CD74HC137PWT delivers active-low outputs (Y0–Y7 go low). Both share identical pinout, latch enable (LE), dual output enables (OE0/OE1), and TSSOP-16 packaging. This polarity difference dictates whether external inverters are needed in the target system.

Does CD74HC237PWT support true 3.3V operation with guaranteed timing?

Yes. The CD74HC237PWT is fully specified down to 2V and up to 6V. At VCC = 3.3V, propagation delay remains within datasheet limits (max 40ns at CL = 50pF, -40°C to +85°C), and input thresholds (VIH ≥ 2.0V, VIL ≤ 1.0V) ensure clean interfacing with standard 3.3V CMOS logic families without level shifting.

Can CD74HC237PWT be used as a demultiplexer, and how is data routed?

Yes. In demultiplexer mode, one output enable (e.g., OE0) serves as the data input, while the other (OE1) is held low (active), and A0–A2 select the destination output. For example, with OE1 = low, OE0 = data, and A2A1A0 = 010, Y2 follows OE0's logic state - enabling single-line-to-eight-channel signal distribution with 13ns typical latency.

What is the maximum capacitive load the CD74HC237PWT can drive reliably?

The CD74HC237PWT is characterized up to 50pF load capacitance in switching specifications. While it can drive higher loads, propagation delay increases linearly (e.g., ~27ns at CL = 50pF, VCC = 5V), and output transition time degrades. For >50pF, consider buffering or reducing trace length; the device's ±25mA output rating supports moderate bus loading but not transmission-line driving.

Is CD74HC237PWT pin-compatible with any HCT-series equivalents?

No. CD74HC237PWT (HC logic) is not pin-compatible with HCT variants like CD74HCT237E due to differing input threshold requirements and lack of documented pin-for-pin mapping in TI's datasheet. HCT devices require 4.5V–5.5V supply and TTL-compatible inputs, making them unsuitable drop-in replacements without voltage and logic-level validation.