74lcx646 STMicroelectronics, 74lcx646 Datasheet - Page 2

• Manufacturer Part Number: 74lcx646
• Description: Low Volt. Cmos Octal Bus Transceiver/register With 5 Volt Tolerant Inputs And Outputs 3-state
• Manufacturer: STMicroelectronics

M74LCX646
(enable G high), "A" data may be stored in one
register and/or "B" data may be stored in the other
register. When an output function is disabled, the
input function is still enabled and may be used to
store and transmit data. Only one of the two
buses, A or B, may be driven at a time. It has
same speed performance at 3.3V than 5V
Figure 2: Input And Output Equivalent Circuit
Table 2: Pin Description
2/16
20, 19, 18, 17, 16, 15, 14, 13
4, 5, 6, 7, 8, 9, 10, 11
PIN N°
21
22
23
12
24
1
2
3
SELECT AB (SAB)
SELECT BA (SBA)
CLOCK AB (CAB)
CLOCK BA (CBA)
SYMBOL
A1 to A8
B1 to B8
GND
V
DIR
G
CC
AC/ACT family, combined with a lower power
consumption.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
A to B Clock Input (LOW to HIGH,
Edge-Triggered)
Select A to B Source Input
Direction Control Input
A Data Inputs/Outputs
B Data Inputs/Outputs
Output Enable Input (Active LOW)
Select B to A Source Input
B to A Clock Input (LOW to HIGH,
Edge Triggered)
Ground (0V)
Positive Supply Voltage
NAME AND FUNCTION