Nexperia USA Inc. 74HCT390DB,112

Overview

74HCT390DB,112 from Nexperia is a dual 4-bit binary/decimal ripple counter IC with asynchronous reset, operating at 4.5–5.5 V supply, 20 MHz max clock frequency, and TTL-compatible inputs. It implements two independent divide-by-2/divide-by-5 counters in one SO-16 package for clock division and frequency synthesis in digital timing circuits.

For engineers reviewing the 74HCT390DB,112 datasheet, 74HCT390DB,112 pinout, 74HCT390DB,112 application, or 74HCT390DB,112 equivalent, key selection criteria include asynchronous reset behavior, cascading capability between sections, propagation delay consistency across sections, and SO-16 thermal performance under sustained 5 V operation.

Technical Context

This device contains two independent 4-bit ripple counter sections: Section A (pins 1–6) provides ÷2 and ÷5 outputs; Section B (pins 12–15) provides ÷2 and ÷5 outputs. Each section features separate clock and reset inputs, enabling independent control and cascaded configuration.

Counting is asynchronous-output transitions occur after internal propagation delays, with t_PHL/t_PLH ≤ 30 ns (V_CC = 5 V, T_A = 25 °C). Input thresholds match TTL logic levels (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V), ensuring interoperability with legacy 74-series logic families.

Key Specifications

Pinout & Package

Package: SO-16 (Small Outline, 150 mil width), surface-mount, JEDEC MS-012AC compliant, 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual decade counter applications.

Compared with 74HC390N and SN74LS390N, the 74HCT390DB,112 uniquely balances TTL-level input compatibility, low static power (< 1 µA), and SO-16 thermal performance-making it optimal for industrial upgrades and space-constrained 5 V systems requiring legacy interoperability.

Availability

74HCT390DB,112 is available at Aetrix Electronics and suitable for digital clock displays, industrial PLC timer modules, and automotive dashboard clusters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74HCT390DB,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 global semiconductor expert focused on high-volume, high-reliability logic, discrete, and MOSFET solutions for industrial, automotive, and computing markets.

The 74HCT series delivers TTL-compatible CMOS logic optimized for robust 5 V system integration, particularly in cost-sensitive, thermally constrained, and long-lifecycle industrial control applications.

FAQ

Can 74HCT390DB,112 be operated at 3.3 V?

No. The 74HCT390DB,112 is specified only for 4.5–5.5 V operation. Its TTL-compatible input thresholds require ≥2.0 V for logic HIGH recognition, and internal circuitry is not characterized below 4.5 V. Attempting 3.3 V operation risks undefined outputs and increased susceptibility to noise.

Is the 74HCT390DB,112 pin-compatible with the 74LS390?

Yes-both devices use identical SO-16 pinouts and share identical truth tables for clock, reset, and output behavior. However, 74HCT390DB,112 draws significantly less quiescent current (≤1 µA vs. ~25 mA) and exhibits different AC characteristics including longer propagation delay (30 ns vs. 15 ns).

Does Section A automatically clock Section B in cascade mode?

Yes-when Q3 (pin 6) of Section A is connected to CP1 (pin 12) of Section B, each full decade (10-clock) cycle of Section A advances Section B by one count. This forms a synchronous ÷100 counter chain, with propagation delay accumulating across both sections (max 60 ns total).

What is the maximum fan-out for 74HCT390DB,112 outputs?

Each output can drive up to 10 74HCT inputs or one standard 74LS input at V_CC = 5 V. This is defined by the ±4 mA output current specification and ensures signal integrity across typical PCB trace lengths without termination.