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.