Nexperia USA Inc. HEF4794BT,112

Overview

HEF4794BT,112 from Nexperia is an 8-stage CMOS serial-in/parallel-out shift-and-store register with open-drain LED driver outputs (QP0–QP7), dual serial outputs (QS1/QS2), strobe-controlled latching, and output enable. It operates from 3 V to 15 V, supports -40 °C to +125 °C ambient, and enables cascaded LED matrix control in industrial signage and panel displays.

For engineers reviewing the HEF4794BT,112 datasheet, HEF4794BT,112 pinout, HEF4794BT,112 application, or HEF4794BT,112 equivalent, key selection considerations include its dual-edge serial cascade capability (QS1 on CP↑, QS2 on CP↓), 15 V absolute max rating, open-drain 40 mA per output, strobe-to-output propagation delay down to 35 ns at 15 V, and SO16 package compatibility with legacy 4000-series logic footprints.

Technical Context

The HEF4794BT,112 implements a two-stage pipeline: an 8-bit shift register followed by an independent 8-bit storage latch. Data shifts on positive clock edges (CP↑); strobe (STR) transfers all 8 bits simultaneously into the latch. Output enable (OE) controls high-impedance state of QP0–QP7.

It provides two asynchronous serial outputs: QS1 delivers shifted data on CP↑ for fast-rise-clock systems; QS2 delivers the same data on the subsequent CP↓, enabling reliable daisy-chaining with slow-rising clocks. All inputs are CMOS-compatible with VIH/VIL specified across 5 V/10 V/15 V supply conditions.

Key Specifications

Pinout & Package

HEF4794BT,112 is housed in a 16-pin SO16 plastic small outline package (SOT109-1), 3.9 mm body width, JEDEC MS-012 compliant, with gull-wing leads and standard 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit shift-and-store LED driver applications.

Compared with SN74HC595DR and STPIC6C595MTR, the HEF4794BT,112 uniquely combines 3–15 V operation, dual-edge serial cascade (QS1/QS2), and guaranteed -40 °C to +125 °C performance - making it the only option for ruggedized, multi-rail, daisy-chained LED control without level shifters or supplemental regulators.

Availability

HEF4794BT,112 is available at Aetrix Electronics and suitable for industrial panel displays, automotive interior lighting control, multi-channel LED signage, and programmable logic interface expansion requiring stable component supply across extended temperature and voltage ranges.

Supply support for HEF4794BT,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 delivering high-performance, reliable, and energy-efficient components for automotive, industrial, computing, consumer, and mobile markets.

The HEF4794B series belongs to Nexperia's legacy logic portfolio, designed specifically for robust serial-to-parallel conversion and LED driving in harsh environments - emphasizing wide voltage operation, ESD resilience, and extended temperature reliability.

FAQ

Can HEF4794BT,112 drive common-anode LEDs directly?

Yes. Its eight open-drain QP0–QP7 outputs each sink up to 40 mA continuously at 15 V, allowing direct connection to common-anode LED segments or digits without external transistors. Ensure current-limiting resistors are sized for the target forward voltage and desired brightness at the applied VDD.

What is the functional difference between QS1 and QS2 outputs?

QS1 outputs the data from shift register stage 6 on every CP rising edge; QS2 outputs the data from stage 7 on the subsequent CP falling edge. This dual-edge arrangement ensures reliable data transfer between cascaded devices regardless of clock rise time - QS1 for fast clocks, QS2 for slow-rising clocks.

Does HEF4794BT,112 require external pull-up resistors on QP outputs?

Yes - open-drain outputs require external pull-ups to VDD (or another positive rail) to establish HIGH logic levels when not sinking current. Pull-up values depend on load capacitance and required rise time; typical values range from 1 kΩ (for fast switching) to 10 kΩ (for low power).

How does strobe (STR) timing affect output update integrity?

STR must remain HIGH for ≥12 ns (at 15 V) to reliably transfer all 8 bits from the shift register to the storage latch. Shorter pulses may cause partial or failed updates. Outputs reflect the latched data only when OE is HIGH; STR timing independence from CP ensures glitch-free parallel updates.