Integrated Device Technology, Inc.
MILITARY AND COMMERCIAL TEMPERATURE RANGES AUGUST 1995
1995 Integrated Device Technology, Inc. 6.9 DSC-4611/4
1
DESCRIPTION:
The IDT octal bidirectional transceivers are built using an
advanced dual metal CMOS technology. The FCT245T/
FCT2245T, FCT640T and FCT645T are designed for asyn-
chronous 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 HIGH Z condition.
The FCT245T/FCT2245T and FCT645T transceivers have
non-inverting outputs. The FCT640T has inverting outputs.
The FCT2245T has balanced drive outputs with current
limiting resistors. This offers low ground bounce, minimal
undershoot and controlled output fall times- reducing the need
for external series terminating resistors. The FCT2xxxT parts
are plug-in replacements for FCTxxxT parts.
FAST CMOS OCTAL
BIDIRECTIONAL
TRANSCEIVERS
IDT54/74FCT245T/AT/CT/DT - 2245T/AT/CT
IDT54/74FCT640T/AT/CT
IDT54/74FCT645T/AT/CT/DT
FEATURES:
• Common features:
– Low input and output leakage ≤1µA (max.)
– CMOS power levels
– True TTL input and output compatibility
– VOH = 3.3V (typ.)
– VOL = 0.3V (typ.)
– Meets or exceeds JEDEC standard 18 specifications
– Product available in Radiation Tolerant and Radiation
Enhanced versions
– Military product compliant to MIL-STD-883, Class B
and DESC listed (dual marked)
– Available in DIP, SOIC, SSOP, QSOP, CERPACK
and LCC packages
• Features for FCT245T/FCT640T/FCT645T:
– Std., A, C and D speed grades
– High drive outputs (-15mA IOH, 64mA IOL)
• Features for FCT2245T:
– Std., A and C speed grades
– Resistor outputs (-15mA IOH, 12mA IOL Com.)
(-12mA IOH, 12mA IOL Mil.)
– Reduced system switching noise
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PIN CONFIGURATIONS
FUNCTIONAL BLOCK DIAGRAM
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The IDT logo is a registered trademark of Integrated Device Technology, Inc.
LCC
TOP VIEW
5
6
7
8
9
10
A1
A2
A3
1
2
3
4
20
19
18
17
16
15
14
13
Vcc
12
11
T/R
B1
A4
A5
A6
A7
OE
B2
B3
B4
B5
B6
GND B7
A0
B0
P20-1
D20-1
SO20-2
SO20-7*
SO20-8**
&
E20-1
INDEX
B0
B1
B2
B3
B4
A2
A3
A4
A5
A6
B
7
B
6
B
GND
A
7
A
0
A
1
VccT/R OE
15
14
5
18
17
16
5
6
7
8
4
L20-2
9 10 11 12 13
32
1
20 19
*FCT245T/2245T, FCT645T only.
**FCT245T/2245T, FCT640T
DIP/SOIC/SSOP/QSOP/CERPACK
TOP VIEW
FCT245T/2245T, FCT645T are non-inverting options.
FCT640T is the inverting options.
A
B0
0
T/R
OE
A
B1
1
A
B2
2
A
B3
3
A
B4
4
A
B5
5
A
B6
6
A
B7
7
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