Texas Instruments SN74BCT652DW

Overview

SN74BCT652DW from Texas Instruments is an octal bus transceiver and register IC with 3-state outputs, designed for bidirectional data multiplexing between A and B buses in TTL-compatible systems. It integrates dual 8-bit D-type flip-flops, independent OE/S control per bus, real-time/stored data selection, and BiCMOS logic delivering 77 MHz max clock frequency, 64 mA sink current, and 0°C to 70°C operating range.

For engineers reviewing the SN74BCT652DW datasheet, SN74BCT652DW pinout, SN74BCT652DW application, or SN74BCT652DW equivalent, key selection criteria include its dual-register architecture, glitch-free select control, power-up high-impedance state, and SOIC-24 package compatibility with legacy 300-mil DIP layouts.

Technical Context

The SN74BCT652DW implements two independent 8-bit bidirectional transceiver paths with integrated storage registers, each controlled by dedicated clock (CLKAB/CLKBA), select (SAB/SBA), and output-enable (OEAB/OEBA) inputs. Its BiCMOS design reduces ICCZ standby current to 10–17 mA while maintaining TTL-level input thresholds (VIH = 2 V, VIL = 0.8 V) and 5 V supply operation.

Real-time transfer occurs when SAB/SBA are low; stored data transfer activates on high select inputs. Clock-triggered latching (low-to-high CLK edge) enables simultaneous A/B bus storage regardless of OE/S states, and the internal logic eliminates multiplexer glitches during mode transitions.

Key Specifications

Pinout & Package

SN74BCT652DW uses a 24-pin SOIC (DW) package with 300-mil width, compatible with standard surface-mount assembly processes and footprint-equivalent to legacy DIP-24 layouts. Pin numbering follows JEDEC MS-013, with no internal connections (NC) at pins 4, 12, and 25.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal transceiver-and-register applications.

Compared with SN74BCT652DW, SN74ACT652DW trades drive strength for ultra-low static power, while SN74LS652N retains full TTL compatibility at the cost of speed and efficiency - making SN74BCT652DW the optimal balance for new designs needing performance, drive, and power efficiency.

Availability

SN74BCT652DW is available at Aetrix Electronics and suitable for industrial backplane arbitration, legacy system interfacing, automated test equipment routing, and dual-bus PLC controller applications requiring stable component supply and long-term obsolescence management.

Supply support for SN74BCT652DW 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, and logic solutions for industrial, automotive, and communications markets.

The SN74BCT652DW belongs to TI's BCT logic family, engineered for high-speed, low-glitch bus management in mixed-technology systems requiring TTL compatibility, register storage, and robust 3-state control.

FAQ

What is the maximum clock frequency supported by the SN74BCT652DW?

The SN74BCT652DW supports a maximum clock frequency of 77 MHz under recommended operating conditions (VCC = 5 V, TA = 25°C). This rating applies to both CLKAB and CLKBA inputs and enables high-speed data latching in real-time or stored-transfer modes. The device maintains timing integrity across its full commercial temperature range (0°C to 70°C), with worst-case propagation delays verified at 11.6 ns for critical paths like OEBA→A.

Does the SN74BCT652DW have built-in ESD protection, and what level is specified?

Yes, the SN74BCT652DW includes on-chip ESD protection exceeding 2000 V per MIL-STD-883C, Method 3015 (Human Body Model) and over 200 V using the Machine Model (C = 200 pF, R = 0). This protection is implemented at all control and I/O pins, supporting robust handling during manufacturing and board assembly without requiring external transient suppressors.

How does the SN74BCT652DW handle bus contention during power-up?

The SN74BCT652DW features a power-up high-impedance mode: all 3-state outputs remain in high-Z until valid VCC and input control levels stabilize. This behavior prevents bus contention during system startup or brown-out recovery. The internal circuitry ensures OEAB and OEBA default to inactive (high) states at power-on, guaranteeing safe isolation of both A and B buses before firmware initializes control signals.

Can the SN74BCT652DW simultaneously store data on both A and B buses?

Yes, the SN74BCT652DW can store data on both A and B buses simultaneously via low-to-high transitions on CLKAB and CLKBA while OEAB and OEBA are inactive (high). The function table confirms "Store A and B data" when OEAB = L, OEBA = H, and both clocks receive synchronous rising edges - enabling atomic snapshot capture across dual buses without intermediate bus states.

What package type and pin count does the SN74BCT652DW use?

The SN74BCT652DW uses a 24-pin SOIC (DW) package with 300-mil body width and standard gull-wing lead form. It shares pin compatibility with the 24-pin plastic DIP (NT) and ceramic flatpack (W) variants of the same family. The DW package supports surface-mount reflow assembly with JEDEC Level-1 moisture sensitivity and NIPDAU lead finish.