Texas Instruments CY74FCT823BTPC

Overview

CY74FCT823BTPC from Texas Instruments is a 9-bit bus-interface register with 3-state outputs, positive-edge-triggered D-type flip-flops, buffered clock-enable (EN) and asynchronous clear (CLR), and TTL-compatible I/O logic levels. It delivers 64 mA sink / 32 mA source drive, supports partial-power-down via Ioff, and operates across –40°C to +85°C in a 24-pin PDIP package. It is used for parity bus interfacing and high-drive output ports in microprogrammed systems.

For engineers reviewing the CY74FCT823BTPC datasheet, CY74FCT823BTPC pinout, CY74FCT823BTPC application, or CY74FCT823BTPC equivalent, key selection criteria include propagation delay (7.5 ns max), Ioff-enabled power-down safety, matched rise/fall times, edge-rate-controlled noise immunity, and compatibility with FCT/F/AM29823 logic families.

Technical Context

This device implements nine independent D-type flip-flops synchronized to the rising edge of CP, with shared EN and CLR controls enabling synchronous data loading or asynchronous reset. All outputs are 3-state controlled by OE, allowing bidirectional bus isolation without external logic.

Its Ioff circuitry actively disables outputs when VCC = 0 V, blocking reverse current flow during partial power-down-critical for hot-swap and mixed-voltage system design. Edge-rate control reduces simultaneous switching noise, while matched tPLH/tPHL ensures minimal skew between bits under load.

Key Specifications

Pinout & Package

Package: 24-pin Plastic Dual In-line Package (PDIP), 0.600-inch width, through-hole mounting.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus-interface register applications.

Compared with CY74FCT823ATPC, CY74FCT823BTPC offers 25% faster propagation for critical timing paths; compared with CY74FCT823CTSOC, it retains through-hole manufacturability and legacy board compatibility while trading 1.5 ns speed for mechanical serviceability.

Availability

CY74FCT823BTPC is available at Aetrix Electronics and suitable for industrial control systems, telecom line-card interfaces, and legacy microprocessor bus expansion requiring stable component supply, long-term obsolescence management, and through-hole assembly support.

Supply support for CY74FCT823BTPC 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 specializing in analog, embedded processing, and logic solutions, with decades of heritage in high-reliability industrial and automotive ICs.

The CY74FCT823BTPC belongs to TI's FCT logic family-designed specifically for 5-V TTL-compatible bus interfacing with enhanced noise immunity, power-down safety, and high-drive capability in industrial environments.

FAQ

What is the maximum clock frequency supported by CY74FCT823BTPC?

CY74FCT823BTPC has a maximum propagation delay of 7.5 ns (tPLH/tPHL) under CL = 50 pF conditions, supporting reliable operation up to approximately 100 MHz in well-terminated, low-skew systems. Actual usable frequency depends on setup/hold margins, bus loading, and PCB layout-designers should verify timing using the full parameter table including tsu = 3 ns and th = 1.5 ns.

Does CY74FCT823BTPC support partial power-down, and how is it implemented?

Yes, CY74FCT823BTPC supports partial power-down via its Ioff feature: when VCC = 0 V, Ioff limits reverse current to ±1 µA even if I/O pins are biased to 4.5 V. This prevents damaging backflow during hot-swap or mixed-rail sequencing. The function is inherent to the silicon design and requires no external circuitry or configuration.

How does CY74FCT823BTPC differ from standard 74FCT823 devices?

CY74FCT823BTPC is the 7.5 ns speed grade variant within the CY74FCT823 family, distinguished from CY74FCT823ATPC (10 ns) and CY74FCT823CTxx (6 ns). It shares identical pinout, logic function, Ioff behavior, and drive strength (64 mA sink / 32 mA source) across all variants-only propagation delay and AC timing parameters differ.

Can CY74FCT823BTPC be used with 3.3-V logic systems?

No-CY74FCT823BTPC is a 5-V-only device with VCC range 4.75–5.25 V and TTL-compatible input thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V). While it can accept 3.3-V logic HIGH signals (which exceed VIH), its outputs swing to ~3.3 V (VOH typ) and are not guaranteed compatible with 3.3-V input thresholds requiring ≥2.4 V. Level translation is recommended for mixed-voltage interconnect.

What is the purpose of the edge-rate control circuitry in CY74FCT823BTPC?

The edge-rate control circuitry in CY74FCT823BTPC intentionally slows output voltage transitions to reduce di/dt-induced noise and electromagnetic interference (EMI). This significantly improves noise characteristics in high-density layouts and mitigates ground bounce on shared power/ground planes-especially critical when driving multiple loads simultaneously.