Texas Instruments CD74HC123M96E4

Overview

CD74HC123M96E4 from Texas Instruments is a dual retriggerable monostable multivibrator with independent resets, operating from 2V to 6V, featuring Schmitt-trigger inputs on both A and B trigger pins, buffered Q and Q̅ outputs, and external RC timing (t_W = 0.45·R_XC_X at V_CC = 5V). It delivers precise pulse generation in industrial control timing circuits requiring wide temperature operation (-55°C to +125°C).

For engineers reviewing the CD74HC123M96E4 datasheet, CD74HC123M96E4 pinout, CD74HC123M96E4 application, or CD74HC123M96E4 equivalent, key selection criteria include retriggerable pulse extension capability, edge-selective triggering (A = trailing, B = leading), overriding reset functionality, and SOIC-16 packaging for high-density PCB layouts.

Technical Context

The CD74HC123M96E4 implements two independent monostable circuits, each with separate A (trailing-edge), B (leading-edge), and R (active-low reset) inputs. Triggering is voltage-level–based via internal Schmitt triggers-not dependent on input rise/fall times-enabling robust noise immunity across varying signal slew rates.

Each monostable supports retriggering during an active output pulse to extend t_W, and allows immediate termination of the output pulse by asserting R low. The minimum external R_X is 5 kΩ; C_X can be as low as 0 pF, enabling sub-microsecond to multi-second pulse widths depending on RC values.

Key Specifications

Pinout & Package

CD74HC123M96E4 is housed in a 16-pin SOIC (D) package (7.4 mm × 10.3 mm, 1.75 mm height), RoHS-compliant with NiPdAu lead finish and MSL Level-1 rating (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar monostable multivibrator applications.

Compared with CD74HC423M96 and SN74LVC1G123DBVR, the CD74HC123M96E4 uniquely supports both trailing- and leading-edge triggering per channel plus retriggerable pulse extension-making it irreplaceable in adaptive timing architectures like closed-loop motor commutation or programmable pulse-width modulation.

Availability

CD74HC123M96E4 is available at Aetrix Electronics and suitable for industrial motor control, automotive diagnostics, test equipment signal conditioning, and medical safety logic requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CD74HC123M96E4 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 CD74HC123 series belongs to TI's High-Speed CMOS Logic family, designed specifically for robust, RC-tunable timing in harsh environments where precision, noise immunity, and wide temperature operation are mandatory.

FAQ

What is the minimum external timing capacitor value supported by the CD74HC123M96E4?

The CD74HC123M96E4 supports C_X = 0 pF as the minimum external timing capacitor value. This enables the shortest possible pulse widths-down to tens of nanoseconds when paired with R_X ≥ 5 kΩ-and allows use of the device as a pure edge-triggered latch when combined with appropriate RC constraints.

Can the CD74HC123M96E4 operate reliably at 3.3V supply voltage?

Yes, the CD74HC123M96E4 operates reliably across 2V to 6V, including 3.3V nominal systems. At V_CC = 3.3V, input thresholds scale proportionally (VIH ≈ 2.3V, VIL ≈ 1.0V), and propagation delays increase moderately (e.g., t_PLH ≈ 90 ns max), maintaining full functionality in mixed-voltage digital systems.

How does the retriggering behavior of the CD74HC123M96E4 differ from the CD74HC423 series?

The CD74HC123M96E4 supports true retriggering: an active input (A or B) during an ongoing output pulse extends t_W from the new trigger edge. In contrast, the CD74HC423 series ignores subsequent triggers until the current pulse completes-making CD74HC123M96E4 essential for applications requiring dynamic pulse length adjustment.

What is the purpose of the separate A and B inputs on each monostable of the CD74HC123M96E4?

The A input responds to trailing edges (high-to-low-to-high), and the B input responds to leading edges (low-to-high-to-low), allowing the CD74HC123M96E4 to synchronize with either transition of an incoming signal without external inverters-critical for quadrature decoding, bidirectional counter gating, and phase-aligned timing in motion control.

Is the CD74HC123M96E4 pin-compatible with other packages in the same family?

Yes, the CD74HC123M96E4 shares identical pinout and electrical characteristics with all other CD74HC123 variants in SOIC-16 (e.g., CD74HC123M, CD74HC123M96), enabling drop-in replacement across tape-and-reel (M96E4) and tube (M) versions without layout changes-only handling and moisture sensitivity (MSL-1) differ.