Members of the Texas Instruments
WidebusE Family
Inputs Are TTL-Voltage Compatible
Independent Registers and Enables for A
and B Buses
Multiplexed Real-Time and Stored Data
Flow-Through Architecture Optimizes
PCB Layout
Distributed VCC and GND Pin Configuration
Minimizes High-Speed Switching Noise
EPICE (Enhanced-Performance Implanted
CMOS) 1-mm Process
500-mA Typical Latch-Up Immunity at
125°C
Package Options Include Plastic 300-mil
Shrink Small-Outline (DL) Packages Using
25-mil Center-to-Center Pin Spacings and
380-mil Fine-Pitch Ceramic Flat (WD)
Packages Using 25-mil Center-to-Center
Spacings

description
The ’ACT16652 are 16-bit bus transceivers
consisting of D-type flip-flops and control circuitry
arranged for multiplexed transmission of data
directly from the data bus or from the internal
storage registers. The devices can be used as two
8-bit transceivers or one 16-bit transceiver.
Complementary 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. A low input
level selects real-time data, and a high input level
selects stored data. 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. Figure 1
illustrates the four fundamental bus-management
functions that can be performed with the
’ACT16652.
Data on the A or B bus, or both, can be stored in the internal D flip-flops by low-to-high transitions at the
appropriate clock (CLKAB or CLKBA) inputs, regardless of the levels on the select-control or output-enable
inputs. When SAB and SBA are in the real-time transfer mode, it is also 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. Thus, when all other data sources to the two sets of bus lines are at high impedance, each
set of bus lines remains at its last state.
The 74ACT16652 is packaged in TI’s shrink small-outline package, which provides twice the I/O pin count and
functionality of standard small-outline packages in the same printed-circuit-board area.
The 54ACT16652 is characterized for operation over the full military temperature range of –55°C to 125°C. The
74ACT16652 is characterized for operation from –40°C to 85°C.