NXP Semiconductors 74HCT393DB,112

Overview

74HCT393DB,112 from Nexperia is a dual 4-bit binary ripple counter IC with TTL-compatible inputs, asynchronous master reset per counter, and HIGH-to-LOW edge-triggered clocking. It operates from 4.5 V to 5.5 V, delivers propagation delays as low as 15 ns (VCC = 4.5 V, CL = 50 pF), and supports up to 48 MHz maximum clock frequency at 5 V. Used in digital timing, frequency division, and address sequencing circuits within industrial control logic.

For engineers reviewing the 74HCT393DB,112 datasheet, 74HCT393DB,112 pinout, 74HCT393DB,112 application, or 74HCT393DB,112 equivalent, this device serves as a drop-in-ready, dual-stage binary divider for legacy TTL-level systems requiring precise ripple counting without synchronous load or preset functionality.

Technical Context

The 74HCT393DB,112 implements two independent 4-bit asynchronous ripple counters, each using cascaded T-type flip-flops triggered on the falling edge of their respective clock inputs (1CP, 2CP). Each counter advances its four outputs (nQ0–nQ3) through binary states 0–15, with no internal carry synchronization between stages - resulting in inherent ripple delay accumulation across bits.

Each counter features a dedicated active-HIGH asynchronous master reset (1MR, 2MR) that forces all four outputs LOW regardless of clock state. Input clamping diodes enable safe interfacing to voltages exceeding VCC when used with current-limiting resistors, supporting mixed-voltage signal conditioning in legacy designs.

Key Specifications

Pinout & Package

74HCT393DB,112 is supplied in SSOP14 (SOT337-1) package - plastic shrink small outline package, 14 leads, body width 5.3 mm. Pin 1 is index-marked; pin count follows standard SO-style numbering (1–14, top view).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual 4-bit binary ripple counter applications.

Compared with 74HC393DB,112 and SN74LS393N, the 74HCT393DB,112 uniquely bridges TTL input compatibility with CMOS power efficiency and extended temperature operation - making it optimal for industrial upgrades of aging 5 V logic systems where reliability and power matter.

Availability

74HCT393DB,112 is available at Aetrix Electronics and suitable for industrial timer modules, legacy bus address decoders, digital signal sampling gates, and UART baud clock generation requiring stable component supply across extended temperature ranges.

Supply support for 74HCT393DB,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 headquartered in Nijmegen, Netherlands, specializing in high-volume logic, analog, and discrete components with emphasis on automotive and industrial reliability.

The 74HCT393DB,112 belongs to Nexperia's 74HCT logic family - engineered for seamless integration into legacy 5 V TTL systems while delivering CMOS-level power efficiency and robust ESD performance.

FAQ

What is the maximum clock frequency supported by the 74HCT393DB,112?

The 74HCT393DB,112 supports a maximum clock frequency of 48 MHz at VCC = 5 V with CL = 15 pF, and 38 MHz at VCC = 4.5 V with CL = 50 pF. These values are measured from clock input (nCP) to first-stage output (nQ0) under specified load and voltage conditions per the official Nexperia datasheet Rev. 9.

Can the two counters be synchronized to share a common clock input?

No - the 74HCT393DB,112 has physically separate clock inputs (1CP and 2CP) with no internal synchronization mechanism. Driving both from the same source is electrically permissible but does not guarantee simultaneous edge arrival due to trace-length mismatches and internal propagation skew; use external flip-flops if true synchronization is required.

Is the SSOP14 (SOT337-1) package RoHS compliant and lead-free?

Yes - the 74HCT393DB,112 in SSOP14 packaging meets RoHS Directive 2011/65/EU and is manufactured with lead-free terminations and halogen-free molding compound, as confirmed in Nexperia's official compliance documentation dated March 2024.

Does the 74HCT393DB,112 support reset during clock activity?

Yes - both master reset inputs (1MR and 2MR) are asynchronous and active HIGH, meaning they force their respective counter outputs (nQ0–nQ3) LOW immediately upon assertion, regardless of clock state or ongoing transitions. No minimum reset pulse width is required beyond the 5 ns recovery time specified in the datasheet.