HD74HCT620 Datasheet, PDF (1/9 Pages) Hitachi Semiconductor – Octal Bus Transceivers (with inverted 3-state outputs)/

HD74HCT620, HD74HCT623
Octal Bus Transceivers (with inverted 3-state outputs)
Octal Bus Transceivers (with 3-state outputs)
REJ03D0671–0200
(Previous ADE-205-561)
Rev.2.00
Mar 30, 2006
Description
This octal bus transceiver is designed for asynchronous two-way communication between data buses. The control
function implementation allows for maximum flexibility in timing.
This device allows data transmission from the A bus to the B bus or from the B bus to the A bus depending upon the
logic levels at the enable inputs (GBA and GAB).
The enable inputs can be used to disable the device so that the buses are effectively isolated.
The dual-enable configuration gives these devices the capability to store data by simultaneous enabling of GBA and
GAB. Each output reinforces its input in this transceiver configuration. Thus, when both control inputs are enabled and
all other data sources to the two sets of bus lines are at high impedance, both sets of bus lines (16 in all) will remain at
their last states. The 8-bit codes appearing on the two sets of buses will be identical for the HD74HCT623 or
complementary for the HD74HCT620.
Features
• LSTTL Output Logic Level Compatibility as well as CMOS Output Compatibility
• High Speed Operation: t_pd (Bus to Bus) = 15 ns typ (C_L = 50 pF)
• High Output Current: Fanout of 15 LSTTL Loads (Q_A to Q_H outputs)
• Wide Operating Voltage: V_CC = 4.5 to 5.5 V
• Low Input Current: 1 µA max
• Low Quiescent Supply Current: I_CC (static) = 4 µA max (Ta = 25°C)
• Ordering Information
Part Name
Package Type
Package Code
(Previous Code)
Package
Abbreviation
HD74HCT623FPEL SOP-20 pin (JEITA)
PRSP0020DD-B
FP
(FP-20DAV)
HD74HCT620RPEL
PRSP0020DC-A
SOP-20 pin (JEDEC)
RP
HD74HCT623RPEL
(FP-20DBV)
Note: Please consult the sales office for the above package availability.
Taping Abbreviation
(Quantity)
EL (2,000 pcs/reel)
EL (1,000 pcs/reel)
Function Table
Enable Inputs
GBA
GAB
L
L
H
H
H
L
L
H
Operation
HD74HCT620
HD74HCT623
B data to A bus
B data to A bus
A data to B bus
A data to B bus
Isolation
Isolation
B data to A bus, A data to B bus B data to A bus, A data to B bus
Rev.2.00 Mar 30, 2006 page 1 of 8