Nexperia USA Inc. HEF4043BT,653

Overview

HEF4043BT,653 from Nexperia is a quad R/S latch IC with 3-state outputs and a common output enable (OE) input, used for synchronous four-bit data storage in bus-oriented digital systems. It operates across 3.0 V to 15.0 V supply, supports -40 °C to +85 °C ambient range, features active-HIGH set/reset inputs, and delivers high-impedance output states when OE is LOW - enabling shared-bus applications such as industrial control I/O expansion.

For engineers reviewing the HEF4043BT,653 datasheet, HEF4043BT,653 pinout, HEF4043BT,653 application, or HEF4043BT,653 equivalent, key selection considerations include its 3-state output timing (tPHZ ≤ 25 ns at 15 V), wide-voltage CMOS compatibility, JEDEC JESD13-B compliance, and SO16 package suitability for space-constrained PCB layouts.

Technical Context

The HEF4043BT,653 implements four independent cross-coupled NAND-based R/S latches, each with dedicated active-HIGH set (nS) and reset (nR) inputs and a buffered 3-state output (nQ). Its common OE input controls output driver enable/disable without affecting internal latch state, supporting bus contention avoidance in multi-master systems.

Input clamp diodes allow safe interfacing to voltages exceeding VDD when used with current-limiting resistors. Static operation ensures zero dynamic power consumption during hold states, while propagation delays scale predictably with load capacitance (e.g., tPLH = 7 ns + 0.16 ns/pF × CL at 15 V).

Key Specifications

Pinout & Package

HEF4043BT,653 is housed in a plastic small outline package (SO16), SOT109-1 variant, with 16 leads, 3.9 mm body width, and standard 1.27 mm lead pitch - compatible with automated surface-mount assembly and IPC-7351B footprint guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad R/S latch with 3-state output applications.

Compared with CD4043BE and 74HC175D, the HEF4043BT,653 uniquely combines asynchronous R/S control, common 3-state enable, JEDEC-compliant ESD robustness, and industrial temperature operation - making it optimal for bus-isolated storage in legacy-compatible industrial controllers.

Availability

HEF4043BT,653 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, legacy bus interface logic, test equipment signal gating, and configurable logic subsystems requiring stable component supply across long product lifecycles.

Supply support for HEF4043BT,653 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, analog, and MOSFET solutions for automotive, industrial, and consumer markets.

The HEF4043BT,653 belongs to Nexperia's legacy CMOS logic portfolio, designed specifically for robust, wide-voltage bus interface and data storage in industrial control and instrumentation systems.

FAQ

What is the maximum capacitive load the HEF4043BT,653 can drive while maintaining specified timing?

The HEF4043BT,653 specifies propagation delay versus load capacitance (CL) in Table 7: tPLH = 7 ns + (0.16 ns/pF) × CL at 15 V. For guaranteed 35 ns max tPLH, CL must not exceed 175 pF. This includes PCB trace capacitance, probe loading, and downstream input capacitance - design must sum all contributors before final layout.

Can the HEF4043BT,653 be used with a 3.3 V microcontroller driving its inputs?

Yes - at VDD = 3.3 V, VIH(min) = 2.31 V and VIL(max) = 0.99 V per Table 6, so standard 3.3 V CMOS outputs meet thresholds with >1.3 V noise margin. However, ensure VDD is stabilized at 3.3 V ±5 %, as the device is not 5 V tolerant at 3.3 V supply.

Does the OE pin affect internal latch state during toggling?

No - OE only controls the output driver stage. As confirmed in Section 1, "OE does not affect the state of the latch." Internal Q/Q̅ states remain unchanged regardless of OE logic level, enabling glitch-free bus arbitration and hot-swap-safe operation.

Is there a recommended pull-up or pull-down for unused nS/nR inputs?

Unused nS/nR inputs must be terminated to VDD or VSS to prevent floating nodes. Per Section 1, inputs include clamp diodes; tying to VDD (for nR) or VSS (for nS) avoids unintended set/reset. Do not leave open - floating inputs increase static current and risk metastability.