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.