IDT54/74FCT621T/AT
FAST CMOS OCTAL BUS TRANSCEIVER (OPEN DRAIN)
MILITARY AND COMMERCIAL TEMPERATURE RANGES
6.18
1
Integrated Device Technology, Inc.
FAST CMOS
OCTAL BUS TRANSCEIVER
(OPEN DRAIN)
DESCRIPTION:
The IDT54/74FCT621T/AT is an octal transceiver with
non-inverting Open-Drain bus compatible outputs in both
send and receive directions. The B bus outputs are capable
of sinking 64mA providing very good capacitive drive
characteristics. These octal bus transceivers are designed for
asynchronous two-way communication between data buses.
The control function implementation allows for maximum
flexibility in timing.
IDT54/74FCT621T/AT
DIP/SOIC/CERPACK
TOP VIEW
FUNCTIONAL BLOCK DIAGRAM
(1)
PIN CONFIGURATIONS
1
MILITARY AND COMMERCIAL TEMPERATURE RANGES
APRIL 1994
1995 Integrated Device Technology, Inc.
6.18
DSC-4222/4
FEATURES:
Std. and A speed grades
Low input and output leakage
1
A (max.)
CMOS power levels
True TTL input and output compatibility
V
OH
= 3.3V (typ.)
V
OL
= 0.3V (typ.)
Power off disable outputs permit "live insertion"
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, CERPACK and LCC packages
B
1
A
2
A
8
7 Other Transceivers
B
2
B
8
A
1
GAB
GBA
2538 drw 01
The IDT logo is a registered trademark of Integreted Device Technology, Inc.
5
6
7
8
9
10
A
1
A
2
A
3
1
2
3
4
20
19
18
17
16
15
14
13
Vcc
12
11
GAB
B
1
A
4
A
5
A
6
A
7
GBA
B
2
B
3
B
4
B
5
B
6
A
8
GND
B
7
B
8
P20-1,
D20-1,
SO20-2
&
E20-1
LCC
TOP VIEW
2538 drw 03
4
5
6
7
8
18
17
16
15
14
INDEX
B
1
B
2
B
3
B
4
B
5
A
3
A
4
A
5
A
6
A
7
B
6
B
7
B
8
GND
A
8
A
1
A
2
Vcc
GAB
GBA
L20-2
9 10 11 12 13
3
2
1
20 19
2538 drw 02
IDT54/74FCT621T/AT
FAST CMOS OCTAL BUS TRANSCEIVER (OPEN DRAIN)
MILITARY AND COMMERCIAL TEMPERATURE RANGES
6.18
2
PIN DESCRIPTION
Pin Names
Description
G
BA, GAB
Enable Inputs
A
1
A
8
A Inputs or Open-drain Outputs
B
1
B
8
B Inputs or Open-drain Outputs
2538 tbl 01
FUNCTION TABLE
(1)
Enable Inputs
G
G
BA
GAB
Function
L
L
B data to A bus
H
H
A data to B bus
H
L
OFF
L
H
B data to A bus
A data to B bus
NOTE:
2538 tbl 02
1. H = HIGH Voltage Level.
L = LOW Voltage Level.
OFF = HIGH if pull-up resistor is connected to Open-Drain output.
ABSOLUTE MAXIMUM RATINGS
(1)
CAPACITANCE
(T
A
= +25
C, f = 1.0MHz)
Symbol
Rating
Commercial
Military
Unit
V
TERM(2)
Terminal Voltage
with Respect to
GND
0.5 to +7.0
0.5 to +7.0
V
V
TERM(3)
Terminal Voltage
with Respect to
GND
0.5 to
V
CC
+0.5
0.5 to
V
CC
+0.5
V
T
A
Operating
Temperature
0 to +70
55 to +125
C
T
BIAS
Temperature
Under Bias
55 to +125
65 to +135
C
T
STG
Storage
Temperature
55 to +125
65 to +150
C
P
T
Power Dissipation
0.5
0.5
W
I
OUT
DC Output
Current
60 to +120 60 to +120 mA
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
2538 lnk 03
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RAT-
INGS 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
V
CC
by +0.5V unless otherwise noted.
2. Input and V
CC
terminals only.
3. Outputs and I/O terminals only.
2538 lnk 04
NOTE:
1. This parameter is measured at characterization but not tested.
IDT54/74FCT621T/AT
FAST CMOS OCTAL BUS TRANSCEIVER (OPEN DRAIN)
MILITARY AND COMMERCIAL TEMPERATURE RANGES
6.18
3
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following conditions Apply Unless Otherwise Specified:
Commercial: T
A
= 0
C to +70
C, V
CC
= 5.0V
5%; Military: T
A
= 55
C to +125
C, V
CC
= 5.0V
10%
Symbol
Parameter
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Unit
V
IH
Input HIGH Level
Guaranteed Logic HIGH Level
2.0
--
--
V
V
IL
Input LOW Level
Guaranteed Logic LOW Level
--
--
0.8
V
I
IH
Input HIGH Current
(5)
V
CC
= Max., V
I
= 2.7V
--
--
1
A
I
IL
Input LOW Current
(5)
V
CC
= Max., V
I
= 0.5V
--
--
1
A
I
I
Input HIGH Current
(5)
V
CC
= Max., V
I
= V
CC
(Max.)
--
--
1
A
V
IK
Clamp Diode Voltage
V
CC
= Min., I
N
= 18mA
--
0.7
1.2
V
I
OH
Output HIGH Current
V
CC
= Max.
V
OH
= Vcc (Max.)
--
--
20
A
V
IN
= V
IH
or V
IL
V
OL
Output LOW Voltage
V
CC
= Min.
I
OL
= 48mA MIL.
(4)
--
0.3
0.55
V
(B Bus)
V
IN
= V
IH
or V
IL
I
OL
= 64mA COM'L.
V
OL
Output LOW Voltage
V
CC
= Min.
I
OL
= 32mA MIL.
(4)
--
0.3
0.5
V
(A Bus)
V
IN
= V
IH
or V
IL
I
OL
= 48mA COM'L.
I
OFF
Input/Output Power Off
V
CC
= 0V, V
IN
or V
O
4.5V
--
--
1
A
Leakage
(5)
V
H
Input Hysteresis
--
--
200
--
mV
I
CC
Quiescent Power Supply
V
CC
= max., V
IN
= GND or Vcc
--
0.01
1
mA
Current
NOTES:
2538 tbl 05
1. For conditions shown as Max. or Min., use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at V
CC
= 5.0V, +25
C ambient.
3. These are maximum I
OL
values per output, for 8 outputs turned on simultaneously. Total maximum I
OL
(all outputs) is 512mA for commercial and
384mA for military. Derate I
OL
for number of outputs exceeding 8 turned on simultaneously.
4. The test limit for this parameter is
5
A at T
A
= 55
C.
5. This parameter is guaranteed but not tested.
IDT54/74FCT621T/AT
FAST CMOS OCTAL BUS TRANSCEIVER (OPEN DRAIN)
MILITARY AND COMMERCIAL TEMPERATURE RANGES
6.18
4
POWER SUPPLY CHARACTERISTICS
Symbol
Parameter
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Unit
I
CC
Quiescent Power Supply Current
V
CC
= Max.
--
0.5
2.0
mA
TTL Inputs HIGH
V
IN
= 3.4V
(3)
I
CCD
Dynamic Power Supply Current
(4)
Vcc = Max.
V
IN
= V
CC
--
0.15
0.25
mA/MHz
Outputs Open
V
IN
= GND
G
BA = GAB = GND or V
CC
One Input Toggling
50% Duty Cycle
I
C
Total Power Supply Current
(6,7)
Vcc = Max.
V
IN
= V
CC
--
1.5
3.5
mA
Outputs Open
V
IN
= GND
G
BA = GAB = GND or V
CC
One Bit Toggling
V
IN
= 3.4V
--
1.8
4.5
at f
i
=10MHz
V
IN
= GND
50% Duty Cycle
Vcc = Max.
V
IN
= V
CC
--
3.0
6.0
(5)
Outputs Open
V
IN
= GND
G
BA = GAB = GND or V
CC
Eight Bits Toggling
V
IN
= 3.4V
--
5.0
14.0
(5)
at f
i
= 2.5MHz
V
IN
= GND
50% Duty Cycle
NOTES:
2538 tbl 06
1. For conditions shown as Max. or Min., use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at V
CC
= 5.0V, +25
C 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 the 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
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
= Input Frequency
N
i
= Number of Inputs at f
i
All currents are in milliamps and all frequencies are in megahertz.
7. This test is performed with outputs tied to GND through a pull-down resistor.
IDT54/74FCT621T
IDT54/74FCT621AT
Com'l.
Mil.
Com'l.
Mil.
Symbol
Parameter
Condition
(1)
Min.
(2)
Max.
Min.
(2)
Max.
Min.
(2)
Max. Min.
(2)
Max.
Unit
t
PLH
Propagation Delay A to B
C
L
= 50pF
5.5
13.0
5.5
13.5
5.5
12.0
5.5
12.5
ns
t
PHL
R
L
= 500
1.5
8.5
1.5
9.5
1.5
6.8
1.5
7.6
t
PLH
Propagation Delay B to A
5.5
12.5
5.5
13.0
5.5
12.0
5.5
12.5
ns
t
PHL
1.5
8.0
1.5
9.0
1.5
6.4
1.5
7.2
t
PLH
Propagation Delay
G
BA to A
5.5
14.0
5.5
14.5
5.5
13.0
5.5
13.5
ns
t
PHL
1.5
8.5
1.5
9.5
1.5
6.8
1.5
7.6
t
PLH
Propagation Delay GAB to B
5.5
14.0
5.5
14.5
5.5
13.0
5.5
13.5
ns
t
PHL
1.5
8.0
1.5
9.0
1.5
6.4
1.5
7.2
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
NOTES:
1. See test circuit and waveforms.
2. Minimum limits are guaranteed but not tested on Propagation Delays.
2538 tbl 07
IDT54/74FCT621T/AT
FAST CMOS OCTAL BUS TRANSCEIVER (OPEN DRAIN)
MILITARY AND COMMERCIAL TEMPERATURE RANGES
6.18
5
TEST CIRCUITS AND WAVEFORMS
TEST CIRCUITS FOR ALL OUTPUTS
SET-UP, HOLD AND RELEASE TIMES
PULSE WIDTH
SWITCH POSITION
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.
ENABLE AND DISABLE TIMES
PROPAGATION DELAY
Test
Switch
Disable Low
Enable Low
Closed
All Other Tests
Open
Open Drain
DEFINITIONS:
C
L
=
Load capacitance: includes jig and probe capacitance.
R
T
=
Termination resistance: should be equal to Z
OUT
of the Pulse
Generator.
2538 drw 03
2538 drw 04
2538 drw 05
2538 drw 06
2538 drw 07
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
2538 lnk 08
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