3-State Bus Driving Inverting Outputs

Buffered Control Inputs

Package Options Include Plastic

Small-Outline (DW), Ceramic Chip Carriers

(FK), and Standard Plastic (N) and Ceramic

(J) 300-mil DIPs

description

These octal D-type edge-triggered flip-flops

feature 3-state outputs designed specifically for

driving highly capacitive or relatively lowimpedance

loads. They are particularly suitable

for implementing buffer registers, I/O ports,

bidirectional bus drivers, and working registers.

On the positive transition of the clock (CLK) input,

the Q outputs are set to the complement of the

logic states set up at the data (D) inputs. The

’ALS534A and SN74AS534 have inverted outputs,

but otherwise are functionally equivalent to

the ’ALS374A and SN74AS374.

A buffered output-enable (OE) input places the

eight outputs in either a normal logic state (high or

low logic levels) or a high-impedance state. In the

high-impedance state, the outputs neither load

nor drive the bus lines significantly. The

high-impedance state and increased drive

provide the capability to drive bus lines without

interface or pullup components.

OE does not affect the internal operations of the flip-flops. Old data can be retained or new data can be entered

while the outputs are off.

The SN54ALS534A is characterized for operation over the full military temperature range of –55°C to 125°C.

The SN74ALS534A and SN74AS534 are characterized for operation from 0°C to 70°C.