Nexperia USA Inc. 74HC137DB,112

Overview

74HC137DB,112 from Nexperia is a 3-to-8 line decoder/demultiplexer with integrated address latches and active LOW mutually exclusive outputs. It features three binary address inputs (A0–A2), latch enable (LE), dual output enables (E1 active LOW, E2 active HIGH), and operates across 2.0–6.0 V supply. Used in microcontroller I/O expansion and memory address decoding where input data must be captured and held independently of subsequent address changes.

For engineers reviewing the 74HC137DB,112 datasheet, 74HC137DB,112 pinout, 74HC137DB,112 application, or 74HC137DB,112 equivalent, key selection criteria include latch timing (tW = 9 ns min at VCC = 6.0 V), propagation delay (tpd = 17 ns typ at VCC = 6.0 V, CL = 50 pF), output drive capability (±4 mA at VCC = 4.5 V), operating temperature range (−40 °C to +125 °C), and SO16 package compatibility with legacy 74HC footprint layouts.

Technical Context

The 74HC137DB,112 implements a synchronous 3-bit address latch followed by an active LOW 3-to-8 decoder. Latch operation is edge-triggered on LE's LOW-to-HIGH transition, freezing A0–A2 values for stable output generation regardless of subsequent address changes.

Output enable logic requires E1 = LOW and E2 = HIGH to activate any Y0–Y7 output; all outputs remain HIGH otherwise. Inputs include clamp diodes enabling safe interfacing to voltages exceeding VCC when used with current-limiting resistors.

Key Specifications

Pinout & Package

74HC137DB,112 is housed in a plastic small outline package (SO16) per SOT109-1 standard: 16-pin, 3.9 mm body width, 1.27 mm lead pitch, gull-wing leads, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HC137DB,112, the 74HC237D,653 offers output polarity flexibility at identical timing and power, while the SN74HC138PWR trades latching for marginal speed gain and lower unit cost - making it viable only when external latch control is already implemented elsewhere in the design.

Availability

74HC137DB,112 is available at Aetrix Electronics and suitable for industrial control panels, legacy bus interface modules, memory address decoding subsystems, and microcontroller I/O expansion requiring stable component supply across extended temperature ranges.

Supply support for 74HC137DB,112 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

Nexperia is a leading semiconductor manufacturer specializing in high-performance, energy-efficient logic, analog, and discrete components for industrial, automotive, and computing applications.

The 74HC137 belongs to Nexperia's 74HC high-speed CMOS logic family, designed for low-power, pin-compatible replacements of legacy TTL devices in systems demanding wide voltage operation and robust noise immunity.

FAQ

What is the minimum pulse width required on the LE input to reliably capture address data?

The LE input requires a minimum HIGH pulse width of 9 ns at VCC = 6.0 V to guarantee proper latching of A0–A2 inputs. This value scales with supply voltage: 10 ns at 4.5 V and 50 ns at 2.0 V per datasheet Table 7. Shorter pulses risk metastability or incomplete capture, especially under temperature extremes.

Can 74HC137DB,112 drive standard TTL inputs directly?

Yes - at VCC = 4.5 V, the 74HC137DB,112 delivers VOH ≥ 3.98 V and VOL ≤ 0.26 V while sinking or sourcing ±4 mA, exceeding TTL input thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V) with margin. No level-shifting circuitry is needed for direct TTL interface.

How does the dual-enable logic (E1 and E2) affect output behavior when both are asserted?

Outputs Y0–Y7 are active LOW only when E1 is LOW AND E2 is HIGH. If E1 is HIGH or E2 is LOW, all outputs remain HIGH regardless of latch contents or address inputs. This two-input enable scheme enables hierarchical decoding trees and prevents partial selection during enable transitions.

Is the 74HC137DB,112 suitable for use with 3.3 V microcontrollers?

Yes - the device operates down to 2.0 V and supports VIH = 2.1 V and VIL = 1.35 V at VCC = 4.5 V, providing full compatibility with 3.3 V logic levels. When powered at 3.3 V, it meets all AC/DC specs per datasheet Table 5 and Table 6, including tpd ≤ 25 ns and ICC ≤ 40 μA.