Texas Instruments CD74HC137PW

Overview

CD74HC137PW 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-low outputs, dual output enables (OE0, OE1), latch enable (LE), and operates across 2V–6V supply range with propagation delay of 31ns (typ) at VCC = 6V, CL = 15pF. Used in industrial control logic and bus interface selection.

For engineers reviewing the CD74HC137PW datasheet, CD74HC137PW pinout, CD74HC137PW application, or CD74HC137PW equivalent, key selection criteria include latch-controlled output isolation, cascading capability via two enable inputs, -55°C to +125°C operating range, and TSSOP-16 package compatibility with high-density PCB layouts.

Technical Context

The CD74HC137PW implements a 3-bit binary address latch followed by an active-low 1-of-8 decoder. Inputs A0–A2 are latched on rising LE, decoupling output states from subsequent address changes. Output enable logic (OE0 and OE1) supports hierarchical cascading and demultiplexing modes.

Its HC-series CMOS architecture delivers LSTTL-compatible drive strength (10 LSTTL loads), low quiescent current (≤160 µA over full temperature range), and balanced transition times - enabling reliable operation in noise-sensitive digital systems without external buffering.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD74HC237PW and SN74HC138PWR, the CD74HC137PW uniquely combines latch-enabled output stability with active-low outputs and dual OE control - making it irreplaceable in systems requiring glitch-free, isolated channel selection during dynamic address updates.

Availability

CD74HC137PW is available at Aetrix Electronics and suitable for industrial control systems, automotive power distribution modules, and test equipment signal routing requiring stable component supply across extended temperature ranges.

Supply support for CD74HC137PW 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 for industrial, automotive, and consumer markets.

The CD74HC137PW belongs to TI's 74HC high-speed CMOS logic family, engineered for low-power, wide-voltage-range digital interfacing in harsh-environment applications demanding robust timing and latch stability.

FAQ

What is the maximum clock frequency supported by the CD74HC137PW?

The CD74HC137PW does not operate on a clock signal - it is combinational logic with latch control. Its maximum usable address update rate is determined by propagation delay (31ns typ at 6V) and setup/hold timing. For reliable operation with clean edges, input transitions should be limited to ≤20 MHz in synchronous systems, assuming adequate setup/hold margins relative to LE timing.

Can the CD74HC137PW replace the CD74HC237PW in an existing design?

No - the CD74HC137PW cannot directly replace the CD74HC237PW because their output polarities differ: CD74HC137PW has active-low outputs (Y0–Y7 go low on selection), while CD74HC237PW has active-high outputs. Swapping them would invert all decoded signals, causing functional failure unless downstream logic is redesigned to accommodate polarity inversion.

Does the CD74HC137PW support 3.3V-only operation?

Yes - the CD74HC137PW is fully specified for 2V–6V operation, including 3.3V nominal supply. At VCC = 3.3V, VIH = 2.31V (min), VIL = 1.0V (max), VOH ≥ 3.2V (at -0.02mA), and VOL ≤ 0.1V (at 0.02mA), ensuring robust interfacing with 3.3V microcontrollers and FPGAs without level-shifting.

What is the purpose of the two output enable inputs (OE0 and OE1) on the CD74HC137PW?

The CD74HC137PW uses OE0 and OE1 to provide flexible output control: both must be low to enable any Y output. This dual-enable structure simplifies cascading - e.g., OE1 can be driven by a higher-order decoder to expand to 1-of-64, or OE0 can serve as data input in demultiplexer mode while OE1 remains low, allowing A0–A2 to select the active output channel.

Is the CD74HC137PW pin-compatible with the SN74HC138?

No - although both are 3-to-8 decoders in TSSOP-16 packages, the CD74HC137PW and SN74HC138PWR have different pinouts. The CD74HC137PW places GND at pin 8 and VCC at pin 16, while SN74HC138PWR places GND at pin 8 but VCC at pin 16 *only in some variants* - more critically, OE signal assignments and output ordering differ. Direct PCB replacement is not possible without layout revision.