SN74ALS533A, SN74AS533A OCTAL D-TYPE TRANSPARENT LATCHES
WITH 3-STATE OUTPUTS
SDAS270 – DECEMBER 1994
• Eight Latches i...
SN74ALS533A, SN74AS533A OCTAL D-TYPE TRANSPARENT LATCHES
WITH 3-STATE OUTPUTS
SDAS270 – DECEMBER 1994
Eight Latches in a Single Package 3-State Bus-Driving Inverting Outputs Full Parallel Access for Loading Buffered Control Inputs
pnp Inputs Reduce dc Loading on
Data Lines
Package Options Include Plastic
Small-Outline (DW) Packages and Standard Plastic (N) 300-mil DIPs
description
These 8-bit D-type transparent latches feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. They are particularly suitable for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers.
DW OR N PACKAGE (TOP VIEW)
OE 1 1Q 2 1D 3 2D 4 2Q 5 3Q 6 3D 7 4D 8 4Q 9 GND 10
20 VCC 19 8Q 18 8D 17 7D 16 7Q 15 6Q 14 6D 13 5D 12 5Q 11 LE
While latch-enable (LE) input is high, the Q outputs follow the complements of the data (D) inputs. When LE is taken low, the Q outputs are latched at the inverses of the levels set up at the D inputs. The SN74ALS533A and SN74AS533A are functionally equivalent to the SN74ALS373A and SN74AS373, except for having inverted outputs.
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 pul...