INDUSTRIAL TEMPERATURE RANGE
IDT74FCT645T/AT/CT/DT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
1
AUGUST 2000
INDUSTRIAL TEMPERATURE RANGE
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
2000 Integrated Device Technology, Inc.
DSC-5512/1
FEATURES:
Std., A, C, and D grades
Low input and output leakage
1A (max.)
CMOS power levels
True TTL input and output compatibility:
V
OH
= 3.3V (typ.)
V
OL
= 0.3V (typ.)
High Drive outputs (-15mA I
OH
, 64mA I
OL
)
Meets or exceeds JEDEC standard 18 specifications
Available in SOIC and QSOP packages
FUNCTIONAL BLOCK DIAGRAM
IDT74FCT645T/AT/CT/DT
FAST CMOS OCTAL
BIDIRECTIONAL
TRANSCEIVER
DESCRIPTION:
The IDT octal bidirectional transceivers are built using an advanced dual
metal CMOS technology. The FCT645T is 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 high Z condition.
A
B
0
0
T/
R
O E
A
B
1
1
A
B
2
2
A
B
3
3
A
B
4
4
A
B
5
5
A
B
6
6
A
B
7
7
INDUSTRIAL TEMPERATURE RANGE
2
IDT74FCT645T/AT/CT/DT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
PIN CONFIGURATION
Symbol
Description
Max
Unit
V
TERM
(2)
Terminal Voltage with Respect to GND
0.5 to +7
V
V
TERM
(3)
Terminal Voltage with Respect to GND
0.5 to V
CC
+0.5
V
T
STG
Storage Temperature
65 to +150
C
I
OUT
DC Output Current
60 to +120
mA
ABSOLUTE MAXIMUM RATINGS
(1)
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause
permanent damage to the device. This is a stress rating only and functional operation
of the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect reliability. No terminal voltage may exceed
Vcc by +0.5V unless otherwise noted.
2. Inputs and Vcc terminals only.
3. Output and I/O terminals only.
Symbol
Parameter
(1)
Conditions
Typ.
Max.
Unit
C
IN
Input Capacitance
V
IN
= 0V
6
10
pF
C
OUT
Output Capacitance
V
OUT
= 0V
8
12
pF
CAPACITANCE
(T
A
= +25C, F = 1.0MHz)
NOTE:
1. This parameter is measured at characterization but not tested.
FUNCTION TABLE
(1)
Inputs
OE
T/R
Outputs
L
L
Bus B Data to Bus A
L
H
Bus A Data to Bus B
H
X
High Z State
Pin Names
Description
OE
Output Enable Input (Active LOW)
T/R
Transmit/Receive Input
A
0
- A
7
Side A Inputs or 3-State Outputs
B
0
- B
7
Side B Inputs or 3-State Outputs
PIN DESCRIPTION
NOTE:
1. H = HIGH Voltage Level
X = Don't Care
L = LOW Voltage Level
SOIC/ SSOP
TOP VIEW
2
3
1
1 6
1 5
1 4
1 1
1 9
1 8
2 0
1 7
1 3
1 2
5
6
7
4
SO20-2
SO20-7
8
9
1 0
A
2
A
0
A
1
V
CC
A
3
A
6
A
4
A
5
A
7
GN D
OE
B
2
B
0
B
1
B
3
B
6
B
4
B
5
B
7
T/R
INDUSTRIAL TEMPERATURE RANGE
IDT74FCT645T/AT/CT/DT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
3
Symbol
Parameter
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Unit
V
IH
Input HIGH Level
Guaranteed Logic HIGH Level
2
--
--
V
V
IL
Input LOW Level
Guaranteed Logic LOW Level
--
--
0.8
V
I
IH
Input HIGH Current
(4)
V
CC
= Max.
V
I
= 2.7V
--
--
1
A
I
IL
Input LOW Current
(4)
V
CC
= Max.
V
I
= 0.5V
--
--
1
A
I
OZH
High Impedance Output Current
V
CC
= Max., V
I
= V
CC
(Max.)
V
I
= 2.7V
--
--
1
A
I
OZL
(3-State Output Pins)
(4)
V
I
= 0.5V
--
--
1
I
I
Input HIGH Current
V
CC
= Max., V
I
= V
CC
(Max.)
--
--
1
A
V
IK
Clamp Diode Voltage
V
CC
= Min., I
IN
= 18mA
--
0.7
1.2
V
V
H
Input Hysteresis
--
--
200
--
mV
I
CC
Quiescent Power Supply Current
V
CC
= Max.
--
0.01
1
mA
V
IN
= GND or V
CC
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: T
A
= 40C to +85C, V
CC
= 5.0V 5%
NOTES:
1. For conditions shown as Min. or Max., use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at V
CC
= 5.0V, +25C ambient.
3. Not more than one output should be tested at one time. Duration of the test should not exceed one second.
4. The test limit for this parameter is 5A at T
A
= 55C.
Symbol
Parameter
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Unit
V
OH
Output HIGH Voltage
V
CC
= Min
I
OH
= 8mA
2.4
3.3
--
V
V
IN
= V
IH
or V
IL
I
OH
= 15mA
2
3
--
V
OL
Output LOW Voltage
V
CC
= Min
I
OL
= 64mA
--
0.3
0.55
V
V
IN
= V
IH
or V
IL
I
OS
Short Circuit Current
V
CC
= Max., V
O
= GND
(3)
60
120
225
mA
OUTPUT DRIVE CHARACTERISTICS
INDUSTRIAL TEMPERATURE RANGE
4
IDT74FCT645T/AT/CT/DT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
Symbol
Parameter
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Unit
I
CC
Quiescent Power Supply Current
V
CC
= Max.
--
0.5
2
mA
TTL Inputs HIGH
V
IN
= 3.4V
(3)
I
CCD
Dynamic Power Supply
V
CC
= Max.
V
IN
= V
CC
--
0.15
0.25
mA/
Current
(4)
Outputs Open
V
IN
= GND
MHz
OE = T/R = GND
One Input Toggling
50% Duty Cycle
I
C
Total Power Supply Current
(6)
V
CC
= Max.
V
IN
= V
CC
--
1.5
3.5
mA
Outputs Open
V
IN
= GND
fi = 10MHz
50% Duty Cycle
V
IN
= 3.4V
--
1.8
4.5
OE = T/R = GND
V
IN
= GND
One Bit Toggling
V
CC
= Max.
V
IN
= V
CC
--
3
6
(5)
Outputs Open
V
IN
= GND
fi = 2.5MHz
50% Duty Cycle
V
IN
= 3.4V
--
5
14
(5)
OE = T/R = GND
V
IN
= GND
Four Bits Toggling
NOTES:
1. For conditions shown as Min. or Max., use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at V
CC
= 5.0V, +25C ambient.
3. Per TTL driven input (V
IN
= 3.4V). All other inputs at V
CC
or GND.
4. This parameter is not directly testable, but is derived for use in Total Power Supply Calculations.
5. Values for these conditions are examples of
I
CC
formula. These limits are guaranteed but not tested.
6. I
C
= I
QUIESCENT
+ I
INPUTS
+ I
DYNAMIC
I
C
= I
CC
+
I
CC
D
H
N
T
+ I
CCD
(f
i
N
i
)
I
CC
= Quiescent Current
I
CC
= Power Supply Current for a TTL High Input (V
IN
= 3.4V)
D
H
= Duty Cycle for TTL Inputs High
N
T
= Number of TTL Inputs at D
H
I
CCD
= Dynamic Current caused by an Input Transition Pair (HLH or LHL)
f
CP
= Clock Frequency for Register Devices (Zero for Non-Register Devices)
f
i
= Output Frequency
N
i
= Number of Outputs at f
i
All currents are in milliamps and all frequencies are in megahertz.
POWER SUPPLY CHARACTERISTICS
IDT74FCT645T
IDT74FCT645AT
IDT74FCT645CT
IDT74FCT645DT
Symbol
Parameter
Condition
(1)
Min.
(2)
Max.
Min.
(2)
Max.
Min.
(2)
Max.
Min.
(2)
Max.
Unit
t
PLH
Propagation Delay
C
L
= 50pF
1.5
9.5
1.5
4.6
1.5
4.1
1.5
3.8
ns
t
PHL
A to B, B to A
R
L
= 500
t
PZH
Output Enable Time
1.5
11
1.5
6.2
1.5
5.8
1.5
5
ns
t
PZL
OE to A or B
t
PHZ
Output Disable Time
1.5
12
1.5
5
1.5
4.8
1.5
4.3
ns
t
PLZ
OE to A or B
t
PZH
Output Enable Time
1.5
11
1.5
6.2
1.5
5.8
1.5
5
ns
t
PZL
T/R to A or B
(3)
t
PHZ
Output Disable Time
1.5
12
1.5
5
1.5
4.8
1.5
4.3
ns
t
PLZ
T/R to A or B
(3)
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
NOTES:
1. See test circuit and waveforms.
2. Minimum limits are guaranteed but not tested on Propagation Delays.
3. This parameter is guaranteed but not tested.
INDUSTRIAL TEMPERATURE RANGE
IDT74FCT645T/AT/CT/DT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
5
Pulse
G enerator
R
T
D .U .T.
V
C C
V
IN
C
L
V
O UT
50pF
500
500
7.0V
3V
1.5V
0V
3V
1.5V
0V
3V
1.5V
0V
3V
1.5V
0V
DATA
IN PUT
TIM ING
INPU T
ASYNC HR O NOU S C ON TROL
PRES ET
C LEA R
ETC.
SYN CH RON OUS C ON TR OL
t
SU
t
H
t
R E M
t
SU
t
H
HIG H-LOW -H IGH
PU LS E
LOW -HIGH -LOW
PU LS E
t
W
1.5V
1.5V
SAM E PHA SE
IN PU T TR ANSITIO N
3V
1.5V
0V
1.5V
V
OH
t
PL H
O UTPU T
OPPOS ITE PH ASE
IN PU T TR ANSITIO N
3V
1.5V
0V
t
P LH
t
PH L
t
PH L
V
OL
CON TRO L
IN PUT
3V
1.5V
0V
3.5V
0V
OU TPUT
NO RM ALLY
LOW
OU TPUT
NO RM ALLY
HIGH
SW ITC H
C LOSE D
SW ITCH
OPEN
V
O L
0.3V
0.3V
t
PLZ
t
PZL
t
P ZH
t
PH Z
3.5V
0V
1.5V
1.5V
ENAB LE
D ISA BLE
V
O H
PRES ET
C LEA R
CLOCK ENABLE
ETC.
Octal link
Octal link
Octal link
Octal link
Octal link
TEST CIRCUITS AND WAVEFORMS
Propagation Delay
Test Circuits for All Outputs
Enable and Disable Times
Set-Up, Hold, and Release Times
Pulse Width
NOTES:
1. Diagram shown for input Control Enable-LOW and input Control Disable-HIGH.
2. Pulse Generator for All Pulses: Rate
1.0MHz; t
F
2.5ns; t
R
2.5ns.
Test
Switch
Open Drain
Disable Low
Closed
Enable Low
All Other Tests
Open
SWITCH POSITION
DEFINITIONS:
C
L
= Load capacitance: includes jig and probe capacitance.
R
T
= Termination resistance: should be equal to Z
OUT
of the Pulse Generator.
INDUSTRIAL TEMPERATURE RANGE
6
IDT74FCT645T/AT/CT/DT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
ORDERING INFORMATION
CORPORATE HEADQUARTERS
for SALES:
for Tech Support:
2975 Stender Way
800-345-7015 or 408-727-6116
logichelp@idt.com
Santa Clara, CA 95054
fax: 408-492-8674
(408) 654-6459
www.idt.com
XX
Tem perature
Range
FCT
IDT
X
Package
SO
PY
Sm all O utline IC (SO 20-2)
Shrink Sm all Outline Package (SO20-7)
645T
645AT
645CT
645DT
O ctal Bidirectional Transceiver
X
D evice
Type
-
40C to +85C
74
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