DM74ALS874B

Features:

Switching specifications at 50 pF 
Switching specifications guaranteed over full tempera-
ture and VCC   range
Advanced oxide-isolated, ion-implanted Schottky TTL
process
3-STATE buffer-type outputs drive bus lines directly
Space saving 300 mil wide package
Asynchronous clear


Specifications

Supply Voltage .................................................................7V
Input Voltage ....................................................................7V
Voltage Applied to Disabled Output...................... 5.5V
Operating Free Air Temperature Range......... 0°C to , 70°C
Storage Temperature Range ...................-65°C to , 150°C
Typical JA
   N Package................... ......................................51.0°C/W
   M Package ............................ ..........................  86.5°C/W


Description

This DM74ALS874B,dual 4-bit register features totem-pole 3-STATE out-puts designed specifically for driving highly-capacitive or relatively low-impedance loads. The high-impedance state and increased high-logic-level drive provide this register with the capability of being connected directly to and driving the bus lines in a bus-organized system without need for interface or pull-up components. It is particularly attractive for implementing buffer registers, I/O ports, bidire ctional bus drivers, and working registers.

The eight flip-flops of the DM74ALS874B are edge-trig-gered D-type flip-flops. On the positive transition of the clock, the Q outputs will be set to the logic states that were set up at the D inputs.

A buffered output control input can be used to place the eight outputs of DM74ALS874B in either a normal logic state (HIGH or LOW logic levels) or a high-impedance state. In the high-imped-ance state the outputs neither load nor drive the bus lines significantly.

The output control of DM74ALS874B does not affect the internal operation of the flip-flops. That is, the old data can be retained or new data can be entered even while the outputs are OFF.