Functionally Equivalent to AMD’s AM29821

Provide Extra Data Width Necessary for

Wider Address/Data Paths or Buses With

Parity

Outputs Have Undershoot-Protection

Circuitry

Power-Up High-Impedance State

Buffered Control Inputs Reduce

dc Loading Effects

Package Options Include Plastic

Small-Outline (DW) Packages and Standard

Plastic (NT) and Ceramic (JT) 300-mil DIPs

description

These 10-bit edge-triggered D-type flip-flops

feature 3-state outputs designed specifically for

driving highly capacitive or relatively low-impedance loads. These devices are particularly suitable for

implementing wider buffer registers, I/O ports, bidirectional bus drivers with parity, and working registers.

On the positive transition of the clock (CLK) input, the Q outputs are true to the data (D) input.

A buffered output-enable (OE) input can place the ten outputs in either a normal logic state (high or low logic

levels) or a high-impedance state. The outputs also are in the high-impedance state during power-up and

power-down conditions. The outputs remain in the high-impedance state while the device is powered down. 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 operation of the flip-flops. Old data can be retained or new data can be entered

while the outputs are in the high-impedance state.

The SN54ALS29821 is characterized for operation over the full military temperature range of −55°C to 125°C.

The SN74ALS29821 is characterized for operation from 0°C to 70°C.