Texas Instruments SN74ALS29823DW

Overview

SN74ALS29823DW from Texas Instruments is a 9-bit bus-interface D-type flip-flop with 3-state outputs, designed for high-capacitance bus driving in industrial and computing systems. It features noninverting data inputs, clock-enable (CLKEN) and clear (CLR) control, buffered OE for high-impedance output management, and operates at 5 V with 0°C to 70°C temperature range.

For engineers reviewing the SN74ALS29823DW datasheet, SN74ALS29823DW pinout, SN74ALS29823DW application, or SN74ALS29823DW equivalent, this device supports wide address/data path buffering, parity bus interfacing, bidirectional bus driving, and I/O port expansion where TTL-compatible timing, undershoot protection, and power-up high-impedance state are required.

Technical Context

The SN74ALS29823DW implements nine edge-triggered D-type flip-flops synchronized to the rising edge of CLK when CLKEN is low; CLKEN high disables clock propagation and latches outputs. CLR asynchronously resets all Q outputs low, independent of clock or enable states.

OE controls output state without affecting internal register operation - outputs enter high-impedance during power-up/down and remain isolated from bus loading. The device uses ALS (Advanced Low-Power Schottky) logic, delivering 24 mA sink and 15 mA source drive capability at VCC = 4.75 V with guaranteed 10 ns propagation delay (CL = 50 pF).

Key Specifications

Pinout & Package

SN74ALS29823DW is housed in a 24-pin SOIC (Small-Outline Integrated Circuit) package with 300-mil width, JEDEC MS-013 compliant, surface-mount compatible.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 9-bit bus-interface flip-flop applications.

Compared with SN74ALS29823DW, SN74AS29823DW trades higher speed for increased power consumption and thermal load, while 74F29823PC offers through-hole compatibility at the cost of modern packaging, undershoot resilience, and SOIC manufacturability - making SN74ALS29823DW optimal for commercial surface-mount systems needing balanced speed, drive, and reliability.

Availability

SN74ALS29823DW is available at Aetrix Electronics and suitable for memory address buffering, parity bus interfacing, I/O port expansion, and bidirectional data bus driving requiring stable component supply in legacy TTL-based industrial and computing platforms.

Supply support for SN74ALS29823DW 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 founded in 1930, specializing in analog, embedded processing, logic, and power management ICs for industrial, automotive, and communications markets.

The SN74ALS29823DW belongs to TI's legacy ALS logic product line, engineered for backward compatibility with TTL systems while delivering improved speed-power trade-offs for bus interface and register applications in mid-1980s–1990s computing infrastructure.

FAQ

What is the operating voltage range for SN74ALS29823DW?

The SN74ALS29823DW operates over a supply voltage range of 4.75 V to 5.25 V, as specified in its recommended operating conditions. This range ensures compatibility with standard 5 V TTL rails while accommodating typical power supply tolerances. Operation outside this range may result in undefined behavior or damage, per absolute maximum ratings limiting VCC to 7 V.

Does SN74ALS29823DW support asynchronous reset?

Yes, SN74ALS29823DW provides an asynchronous active-low clear (CLR) input that forces all nine Q outputs low independently of CLK, CLKEN, or OE states. This function operates immediately upon CLR assertion and does not require clock edges, enabling immediate bus reset or system initialization sequencing without timing dependencies.

How does the clock-enable (CLKEN) pin affect SN74ALS29823DW functionality?

When CLKEN is low, the SN74ALS29823DW allows CLK rising edges to trigger data capture at the D inputs; when CLKEN is high, the internal clock buffer is disabled, freezing the Q outputs at their last valid state. This enables gated clocking for power reduction or conditional register updates without altering OE or CLR control.

Is SN74ALS29823DW pin-compatible with other 9-bit bus-interface flip-flops?

SN74ALS29823DW shares identical pinout and function with SN54ALS29823 (military grade) and is functionally equivalent to AMD's AM29823, but is not pin-compatible with F- or AS-family variants like SN74F29823 or SN74AS29823 due to differing internal architecture and timing characteristics - always verify package drawing DW and logic family specifications before substitution.

What is the purpose of undershoot-protection circuitry in SN74ALS29823DW?

The undershoot-protection circuitry in SN74ALS29823DW prevents output voltages from dropping significantly below GND during fast signal transitions, especially under heavy capacitive loading. This protects downstream receivers from false triggering and reduces EMI, enhancing signal integrity in noisy industrial bus environments where long traces or unterminated lines are common.