INDUSTRIAL TEMPERATURE RANGE
IDTQS74FCT2245T/AT/CT
HIGH-SPEED CMOS 8-BIT TRANSCEIVER
1
DECEMBER 2000
INDUSTRIAL TEMPERATURE RANGE
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
2000 Integrated Device Technology, Inc.
DSC-5404/3
FEATURES:
CMOS power levels: <7.5mW static
Undershoot clamp diodes on all inputs
True TTL input and output compatibility
Ground bounce controlled outputs
Reduced output swing of 0 to 3.5V
Built-in 25
series resistor outputs reduce reflection and other
system noise
Std., A, and C speed grades with 4.1ns t
PD
for C
I
OL
= 12mA
Available in SOIC and QSOP packages
FUNCTIONAL BLOCK DIAGRAM
IDTQS74FCT2245T/AT/CT
HIGH-SPEED CMOS
8-BIT TRANSCEIVER
DESCRIPTION:
The IDTQS74FCT2245T is an 8-bit non-inverting transceiver that has
three-state outputs, ideal for bus-oriented applications. The Transmit/
Receive (T/R) input determines the direction of data flow, either from A to
B or B to A, and the Output Enable (OE) input enables the selected port for
output. The QS74FCT2245 has a 25
resistor output that is useful for
driving transmission lines and reducing system noise. The QS74FCT2245
parts can replace the 245 series to reduce noise in an existing design. All
inputs have clamp diodes for undershoot noise suppression. All outputs
have ground bounce suppression. Outputs will not load an active bus when
Vcc is removed from the device.
T/R
Ax
Bx
OE
25
25
INDUSTRIAL TEMPERATURE RANGE
2
IDTQS74FCT2245T/AT/CT
HIGH-SPEED CMOS 8-BIT TRANSCEIVER
PIN CONFIGURATION
Symbol
Description
Max
Unit
V
TERM
Terminal Voltage with Respect to GND
0.5 to +7
V
T
STG
Storage Temperature
65 to +150
C
I
OUT
DC Output Current Max Current Sink/Pin
+120
mA
I
IK
Input Diode Current, V
IN
< 0
-20
mA
I
OK
DC Output Current, V
OUT
< 0
-50
mA
ABSOLUTE MAXIMUM RATINGS
(1)
NOTE:
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.
Symbol
Parameter
(1)
Conditions
Typ.
Max.
Unit
C
IN
Input Capacitance
V
IN
= 0V
4
--
pF
C
OUT
Output Capacitance
V
OUT
= 0V
8
--
pF
CAPACITANCE
(T
A
= +25C, F = 1.0MHz)
NOTE:
1. This parameter is measured at characterization but not tested.
Pin Names
I/O
Description
A x
I/O
Data Bus A
B x
I/O
Data Bus B
T/R
I
Direction
OE
I
Output Enable Input (Active LOW)
PIN DESCRIPTION
SOIC/ QSOP
TOP VIEW
NOTE:
1. H = HIGH Voltage Level
X = Don't Care
L = LOW Voltage Level
Z = High-Impedance
FUNCTION TABLE
(1)
OE
T/R
A
B
Function
H
X
Z
Z
Disable
L
L
Output
Input
Bus B to Bus A
L
H
Input
Output
Bus A to Bus B
2
3
1
A
1
V
CC
16
15
14
B
4
B
3
B
5
B
1
B
2
11
B
7
B
6
B
0
19
18
20
17
13
12
T/R
5
6
A
6
7
A
4
A
5
4
A
2
A
3
8
9
GND
10
A
7
A
0
OE
INDUSTRIAL TEMPERATURE RANGE
IDTQS74FCT2245T/AT/CT
HIGH-SPEED CMOS 8-BIT TRANSCEIVER
3
Symbol
Parameter
Test Conditions
Min.
Typ.
(1)
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
V
T
Input Hysteresis
V
TLH
- V
THL
for all inputs
--
0.2
--
V
I
IH
Input HIGH Current
V
CC
= Max.
0
V
IN
V
CC
--
--
5
A
I
IL
Input LOW Current
I
OZ
Off-State Output Current (Hi-Z)
V
CC
= Max.
0
V
IN
V
CC
--
--
5
A
I
OR
Current Drive
V
CC
= Max., V
OUT
= 2V
(2)
50
--
--
mA
V
IC
Input Clamp Voltage
V
CC
= Min., I
IN
= 18mA, T
A
= 25C
(2)
--
0.7
1.2
V
V
OH
Output HIGH Voltage
V
CC
= Min.
I
OH
= 15mA
2.4
--
--
V
V
OL
Output LOW Voltage
V
CC
= Min.
I
OL
= 12mA
--
--
0.5
V
R
OUT
Output Resistance
V
CC
= Min.
I
OL
= 12mA
20
28
40
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. Typical values are at V
CC
= 5.0V, +25C ambient.
2. This parameter is guaranteed but not tested.
Symbol
Parameter
Test Conditions
(1)
Min.
Max.
Unit
I
CC
Quiescent Power Supply Current
V
CC
= Max.
--
1.5
mA
freq = 0
0V
V
IN
0.2V or
V
CC
- 0.2V
V
IN
V
CC
I
CC
Supply Current per Input TTL Inputs HIGH
V
CC
= Max.
--
2
mA
V
IN
= 3.4V
(2)
freq = 0
I
CCD
Supply Current per Input per MHz
V
CC
= Max.
--
0.25
mA/
Outputs Open and Enabled
MHz
One Bit Toggling
50% Duty Cycle
Other inputs at GND or V
CC(3,4)
NOTES:
1. For conditions shown as Min. or Max., use appropriate value specified under DC Electrical Characteristics.
2. Per TTL driven input (V
IN
= 3.4V).
3. For flip-flops, I
CCD
is measured by switching one of the data input pins so that the output changes every clock cycle. This is a measurement of device power consumption
only and does not include power to drive load capacitance or tester capacitance.
4. I
C
= I
QUIESCENT
+ I
INPUTS
+ I
DYNAMIC
I
C
= I
CC
+
I
CC
D
H
N
T
+ I
CCD
(f
CP
/2 + 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 Output 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
INDUSTRIAL TEMPERATURE RANGE
4
IDTQS74FCT2245T/AT/CT
HIGH-SPEED CMOS 8-BIT TRANSCEIVER
NOTES:
1. C
LOAD
= 50pF, R
LOAD
= 500
unless otherwise noted.
2. Minimums guaranteed but not tested.
3. This parameter is guaranteed by design but not tested.
74FCT2245T
74FCT2245AT
74FCT2245CT
Symbol
Parameter
(2)
Min.
Max.
Min.
Max.
Min.
Max.
Unit
t
PLH
Propagation Delay
1.5
7
1.5
4.6
1.5
4.1
ns
t
PHL
Ax to/from Bx
t
PZH
Output Enable Time
1.5
9.5
1.5
6.2
1.5
5.8
ns
t
PZL
OE, T/R to A/B
t
PHZ
Output Disable Time
(3)
1.5
7.5
1.5
5
1.5
4.5
ns
t
PLZ
OE, T/R to A/B
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
(1)
INDUSTRIAL TEMPERATURE RANGE
IDTQS74FCT2245T/AT/CT
HIGH-SPEED CMOS 8-BIT TRANSCEIVER
5
Pulse
Generator
R
T
D.U.T.
V
CC
V
IN
C
L
V
OUT
50pF
500
500
7.0V
3V
1.5V
0V
3V
1.5V
0V
3V
1.5V
0V
3V
1.5V
0V
DATA
INPUT
TIMING
INPUT
ASYNCHRONOUS CONTROL
PRESET
CLEAR
ETC.
SYNCHRONOUS CONTROL
t
SU
t
H
t
REM
t
SU
t
H
HIGH-LOW-HIGH
PULSE
LOW-HIGH-LOW
PULSE
t
W
1.5V
1.5V
SAME PHASE
INPUT TRANSITION
3V
1.5V
0V
1.5V
V
OH
t
PLH
OUTPUT
OPPOSITE PHASE
INPUT TRANSITION
3V
1.5V
0V
t
PLH
t
PHL
t
PHL
V
OL
CONTROL
INPUT
3V
1.5V
0V
3.5V
0V
OUTPUT
NORMALLY
LOW
OUTPUT
NORMALLY
HIGH
SWITCH
CLOSED
SWITCH
OPEN
V
OL
0.3V
0.3V
t
PLZ
t
PZL
t
PZH
t
PHZ
3.5V
0V
1.5V
1.5V
ENABLE
DISABLE
V
OH
PRESET
CLEAR
CLOCK ENABLE
ETC.
FCTL link
FCTL link
FCTL link
FCTL link
FCTL 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.
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