PI74FCT245T/640T/645T
PI74FCT2245T/2640T/2645T
(25Ω Series)
Fast CMOS Octal
Bidirectional Transceivers
ProductFeatures
ProductDescription
PI74FCT245/640/645TandPI74FCT2245/2640T/2645Tarepin
compatible with bipolar FAST Series at a higher speed and
lower power consumption
25 Ohm series resistor on all outputs (FCT2XXX only)
TTL input and output levels
Pericom Semiconductors PI74FCT series of logic circuits are
produced using the Companys advanced 0.6/0.8 micron CMOS
technology, achieving industry leading speed grades. All
PI74FCT2XXXdeviceshaveabuilt-in25Ohmseriesresistoronall
outputs to reduce noise because of reflections, thus eliminating the
need for an external terminating resistor.
Low ground bounce outputs
Extremelylowstaticpower
Hysteresis on all inputs
Industrial operating temperature range: 40°C to +85°C
Packagesavailable:
20-pin173milwideplasticTSSOP(L)
20-pin300milwideplasticDIP(P)
20-pin150milwideplasticQSOP(Q)
20-pin150milwideplasticTQSOP(R)
20-pin300milwideplasticSOIC(S)
20-pin209milwideplasticSSOP(H)
Device models available on request
ThePI74FCT245T/640T/645TandPI74FCT2245T/2640T/2645Tare
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
throughthebidirectionaltransceiver.Transmit(activeHIGH)enables
datafromAportstoBports, andreceive(activeLOW)fromBports
toAports.Theoutputenable(OE)input,whenHIGH,disablesboth
A and B ports by placing them in HIGH Z condition.
ProductPinConfiguration
T/R
1
2
3
4
5
6
7
8
9
10
20 Vcc
19 OE
A0
A1
A2
A3
A4
A5
A6
A7
LogicBlockDiagram
B0
B1
B2
B3
B4
B5
B6
B7
18
17
16
15
14
13
12
11
20-Pin
L,P,Q
R,S,H
T/R
OE
A0
B0
A1
B1
A2
GND
ProductPinDescription
PinName
OE
Description
3-State Output Enable Inputs (Active LOW)
Transmit/ReceiveInput
Side A Inputs or 3-State Outputs
Side B Inputs or 3-State Outputs
Ground
B2
T/R
A3
A0-A7
B0-B7
GND
B3
A4
B4
V
CC
Power
A5
(1)
TruthTable
B5
Inputs
A6
OE
L
T/R
Outputs
(2)
L
H
X
Bus B Data to Bus A
B6
(2)
L
Bus A Data to Bus B
A7
H
High Z State
B7
1. H = High Voltage Level, X = Don't Care, L = Low
Voltage Level, Z = High Impedance
2. 640 is inverting from input to output.
FCT245, 2245, 645, 2645 are non-inverting options.
FCT640 & FCT2640 are inverting options.
PS2012B
09/22/99
1