State-of-the-Art BiCMOS Design

Significantly Reduces ICCZ

ESD Protection Exceeds 2000 V Per

MIL-STD-883C, Method 3015; Exceeds

200 V Using Machine Model (C = 200 pF,

R = 0)

Independent Registers and Enables for

A and B Buses

Multiplexed Real-Time and Stored Data

Power-Up High-Impedance Mode

Package Options Include Plastic

Small-Outline (DW) Packages, Ceramic

Chip Carriers (FK) and Flatpacks (W), and

Standard Plastic and Ceramic 300-mil DIPs

(JT, NT)

description

These devices consist of bus transceiver circuits,

D-type flip-flops, and control circuitry arranged for

multiplexed transmission of data directly from the

data bus or from the internal storage registers.

Output-enable (OEAB and OEBA) inputs are

provided to control the transceiver functions.

Select-control (SAB and SBA) inputs are provided

to select whether real-time or stored data is

transferred. The circuitry used for select control

eliminates the typical decoding glitch that occurs

in a multiplexer during the transition between

stored and real-time data. A low input selects

real-time data, and a high input selects stored

data. Figure 1 illustrates the four fundamental

bus-management functions that can be performed

with the ′BCT652.

Data on the A or B data bus, or both, can be stored in the internal D-type flip-flops by low-to-high transitions at

the appropriate clock (CLKAB or CLKBA) inputs regardless of the select- or enable-control pins. When SAB and

SBA are in the real-time transfer mode, it is possible to store data without using the internal D-type flip-flops by

simultaneously enabling OEAB and OEBA. In this configuration each output reinforces its input. Therefore,

when all other data sources to the two sets of bus lines are at high impedance, each set of bus lines remain at

its last state.

The SN54BCT652 is characterized for operation over the full military temperature range of −55°C to 125°C. The

SN74BCT652 is characterized for operation from 0°C to 70°C.