PI74FCT245T
PI74FCT2245T (25Ω Series)
Ω
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Fast CMOS Octal Bidirectional Transceivers
Features
Description
• Pin compatible with bipolar FAST™ Series at a higher speed
and lower power consumption
• 25-ohm series resistor on all outputs (FCT2245Tonly)
• TTL input and output levels
• Low ground bounce outputs
• Extremely low static power
• Hysteresis on all inputs
• Industrial operating temperature range: –40°C to +85°C
• Device models available on request
• Packaging:
– 20-pin 173-mil wide plastic TSSOP (L)
– 20-pin 150-mil wide plastic QSOP (Q)
– 20-pin 300-mil wide plastic SOIC (S)
– 20-pin 209-mil wide plastic SSOP (H)
Pericom Semiconductor’s PI74FCT245T and PI74FCT2245T are
8-bit wide octal buffer bidirectional transceivers designed for
asynchronous two-way communication between data buses. The
transmit/receive (T/R) input determines the direction of data flow
through the bidirectional transceiver. Transmit (active HIGH) enables
data from A ports to B ports, and receive (active LOW) from B ports
to A ports. The output enable (OE) input, when HIGH, disables both
A and B ports by placing them in Hi-Z condition.
PI74FCT2245T has a built-in 25-ohm series resistor on all outputs to
reduce noise because of reflections, thus eliminating the need for an
external terminating resistor.
Pin Configuration
T/R
A0
A1
A2
A3
A4
A5
A6
A7
GND
Block Diagram
T/R
OE
A0
B0
A1
1
20
2
19
3
18
4 20-Pin 17
L
5
16
Q
6
15
S
7
14
H
8
13
9
12
10
11
Vcc
OE
B0
B1
B2
B3
B4
B5
B6
B7
Pin Description
B1
Pin Name
OE
T/R
A0-A7
B0-B7
GND
VCC
A2
B2
A3
B3
A4
B4
Description
3-State Output Enable Inputs (Active LOW)
Transmit/Receive Input
Side A Inputs or 3-State Outputs
Side B Inputs or 3-State Outputs
Ground
Power
Truth Table(1)
A5
Inputs
OE
T/R
L
L
L
H
H
X
B5
A6
B6
A7
B7
1.
1
Outputs
Bus B Data to Bus A(2)
Bus A Data to Bus B(2)
High Z State
H = High Voltage Level, X = Don't Care, L = Low
Voltage Level, Z = High Impedance
PS2012C
10/07/04
