IDT54/74FCT621T/AT
FAST CMOS OCTAL BUS TRANSCEIVER (OPEN DRAIN)
MILITARY AND COMMERCIAL TEMPERATURE RANGES
FAST CMOS
OCTAL BUS TRANSCEIVER
(OPEN DRAIN)
IDT54/74FCT621T/AT
FEATURES:
−
−
−
−
−
−
−
−
−
−
Std. and A speed grades
Low input and output leakage
≤1µ
A (max.)
Extended commercial range of –40°C to +85°C
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
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.
FUNCTIONAL BLOCK DIAGRAM
GBA
GAB
19
1
A
1
2
18
B
1
A
2
-A
8
B
2
-B
8
SEVEN OTH ER TRAN SCEIVERS
MILITARY AND COMMERCIAL TEMPERATURE RANGES
1
c
1999 Integrated Device Technology, Inc.
AUGUST 1999
DSC-2538/6
IDT54/74FCT621T/AT
FAST CMOS OCTAL BUS TRANSCEIVER (OPEN DRAIN)
MILITARY AND COMMERCIAL TEMPERATURE RANGES
PIN CONFIGURATION
GAB
A
2
A
1
GAB
A
1
A
2
A
3
A
4
A
5
A
6
A
7
A
8
GND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
P20-1
1 6
D20-1
SO20-2
1 5
E20-1
V
CC
GBA
B
1
B
2
B
3
B
4
B
5
B
6
B
7
INDEX
3
2
1
20
19
18
17
A
3
A
4
A
5
A
6
A
7
GBA
V
CC
4
5
6
7
8
9
10
B
1
B
2
B
3
B
4
B
5
L20-2
16
15
14
14
13
12
11
11
12
13
B
8
B
7
B
8
GND
DIP/ SOIC/ CERPACK
TOP VIEW
LCC
TOP VIEW
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
V
TERM(2)
V
TERM(3)
T
STG
I
OUT
Rating
Terminal Voltage with Respect to GND
Terminal Voltage with Respect to GND
Storage Temperature
DC Output Current
Max.
–0.5 to +7
–0.5 to V
CC
+0.5
–65 to +150
–65 to +120
Unit
V
V
°C
mA
8T-link
PIN DESCRIPTION
Pin Names
GBA,
GAB
A
1
– A
8
B
1
– B
8
Enable Inputs
A Inputs or Open-drain Outputs
B Inputs or Open-drain Outputs
Description
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. Outputs and I/O terminals only.
FUNCTION TABLE
(1)
Enable Inputs
GBA
L
H
H
L
GAB
L
H
L
H
Function
B data to A bus
A data to B bus
OFF
B data to A bus
A data to B bus
CAPACITANCE
(T
A
= +25
O
C, f = 1.0MHz)
Symbol
C
IN
C
OUT
Parameter
(1)
Input Capacitance
Output Capacitance
Conditions
V
IN
= 0V
V
OUT
= 0V
Typ.
6
8
Max.
10
12
Unit
pF
pF
8T-link
NOTE:
1. H = HIGH Voltage Level.
L = LOW Voltage Level.
OFF = HIGH if pull-up resistor is connected to Open-Drain output.
NOTE:
1. This parameter is measured at characterization but not tested.
2
B
6
A
8
IDT54/74FCT621T/AT
FAST CMOS OCTAL BUS TRANSCEIVER (OPEN DRAIN)
MILITARY AND COMMERCIAL TEMPERATURE RANGES
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following conditions Apply Unless Otherwise Specified:
Commercial: T
A
= –40°C to +85°C, V
CC
= 5.0V ± 5%; Military: T
A
= –55°C to +125°C, V
CC
= 5.0V ± 10%
Symbol
V
IH
V
IL
I
IH
I
IL
I
I
V
IK
I
OH
V
OL
V
OL
I
OFF
V
H
I
CC
Parameter
Input HIGH Level
Input LOW Level
Input HIGH Current
(4)
Input LOW Current
(4)
Input HIGH Current
(4)
Clamp Diode Voltage
Output HIGH Current
Output LOW Voltage
(B Bus)
Output LOW Voltage
(A Bus)
Input/Output Power Off
Leakage
(4)
Input Hysteresis
Quiescent Power Supply
Current
NOTES:
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 ±5µA at T
A
= –55°C.
Test Conditions
(1)
Guaranteed Logic HIGH Level
Guaranteed Logic LOW Level
V
CC
= Max., V
I
= 2.7V
V
CC
= Max., V
I
= 0.5V
V
CC
= Max., V
I
= V
CC
(Max.)
V
CC
= Min., I
N
= –18mA
V
CC
= Max.
V
IN
= V
IH
or V
IL
V
CC
= Min.
V
IN
= V
IH
or V
IL
V
CC
= Min.
V
IN
= V
IH
or V
IL
V
CC
= 0V, V
IN
or V
O
- 4.5V
—
V
CC
= max., V
IN
= GND or Vcc
—
I
OL
= 48mA MIL.
(3)
I
OL
= 64mA COM’L.
I
OL
= 32mA MIL.
(3)
I
OL
= 48mA COM’L.
V
OH
= Vcc (Max.)
Min.
2
—
—
—
—
—
—
—
—
—
—
0.01
Typ.
(2)
—
—
—
—
—
–0.7
—
0.3
0.3
—
200
1
Max.
—
0.8
±1
±1
±1
–1.2
20
0.55
0.5
±1
—
mA
Unit
V
V
µA
µA
µA
V
µA
V
V
µA
mV
3
IDT54/74FCT621T/AT
FAST CMOS OCTAL BUS TRANSCEIVER (OPEN DRAIN)
MILITARY AND COMMERCIAL TEMPERATURE RANGES
POWER SUPPLY CHARACTERISTICS
Symbol
∆I
CC
I
CCD
Parameter
Quiescent Power Supply Current
TTL Inputs HIGH
Dynamic Power Supply Current
(4)
V
CC
= Max.
V
IN
= 3.4V
(3)
Vcc = Max.
Outputs Open
GBA
= GAB = GND or V
CC
One Input Toggling
50% Duty Cycle
Vcc = Max.
Outputs Open
GBA
= GAB = GND or V
CC
One Bit Toggling
at f
i
=10MHz
50% Duty Cycle
Vcc = Max.
Outputs Open
GBA
= GAB = GND or V
CC
Eight Bits Toggling
at f
i
= 2.5MHz
50% Duty Cycle
V
IN
= V
CC
V
IN
= GND
Test Conditions
(1)
Min.
—
—
Typ.
(2)
0.5
0.15
Max.
2
0.25
Unit
mA
mA/MHz
I
C
Total Power Supply Current
(6,7)
V
IN
= V
CC
V
IN
= GND
V
IN
= 3.4V
V
IN
= GND
V
IN
= V
CC
V
IN
= GND
V
IN
= 3.4V
V
IN
= GND
—
1.5
3.5
mA
—
1.8
4.5
—
3
6
(5)
14.0
(5)
—
5
NOTES:
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.
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
IDT54/74FCT621T
Com’l.
Symbol
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
NOTES:
1. See test circuit and waveforms.
2. Minimum limits are guaranteed but not tested on Propagation Delays.
IDT54/74FCT621AT
Com’l.
Min.
(2)
5.5
1.5
5.5
1.5
5.5
1.5
5.5
1.5
Max.
12
6.8
12
6.4
13
6.8
13
6.4
Min.
(2)
5.5
1.5
5.5
1.5
5.5
1.5
5.5
1.5
Mil.
Max.
12.5
7.6
12.5
7.2
13.5
7.6
13.5
7.2
ns
ns
ns
Unit
ns
Max.
13.5
9.5
13
9
14.5
9.5
14.5
9
Mil.
Min.
(2)
5.5
1.5
5.5
1.5
5.5
1.5
5.5
1.5
Parameter
Propagation Delay A to B
Propagation Delay B to A
Propagation Delay
GBA
to A
Propagation Delay GAB to B
Condition
(1)
C
L
= 50pF
R
L
= 500Ω
Min.
(2)
5.5
1.5
5.5
1.5
5.5
1.5
5.5
1.5
Max.
13
8.5
12.5
8
14
8.5
14
8
4
IDT54/74FCT621T/AT
FAST CMOS OCTAL BUS TRANSCEIVER (OPEN DRAIN)
MILITARY AND COMMERCIAL TEMPERATURE RANGES
TEST CIRCUITS AND WAVEFORMS
TEST CIRCUITS FOR ALL OUTPUTS
V
CC
500
Ω
V
IN
Pulse
Generator
D.U.T.
50pF
R
T
SWITCH POSITION
Test
Open Drain
Disable Low
Enable Low
All Other Tests
Open
8-link
7.0V
Switch
Closed
V
OUT
500
Ω
C
L
DEFINITIONS:
C
L
= Load capacitance: includes jig and probe capacitance.
R
T
= Termination resistance: should be equal to Z
OUT
of the Pulse
Generator.
O ctal lin k
SET-UP, HOLD, AND RELEASE TIMES
DATA
INPUT
t
SU
TIM ING
INPUT
ASYNCHRONOUS C ONTROL
PRES ET
CLEAR
ETC.
SYNCHRO NOUS CONTRO L
PRES ET
CLEAR
CLOCK ENABLE
ETC.
t
REM
t
H
3V
1.5V
0V
3V
1.5V
0V
3V
1.5V
0V
3V
1.5V
0V
O ctal lin k
PULSE WIDTH
LO W -HIGH-LOW
PULSE
t
W
HIGH-LOW -HIGH
PULSE
O ctal lin k
1.5V
1.5V
t
SU
t
H
PROPAGATION DELAY
SAM E PHASE
INPUT TRANSITION
t
PLH
OUTPUT
t
PLH
OPPOSITE P HASE
INPUT TRANSITION
t
PH L
t
PH L
3V
1.5V
0V
V
OH
1.5V
V
OL
3V
1.5V
0V
O ctal lin k
ENABLE AND DISABLE TIMES
ENAB LE
DISA BLE
3V
CO NTROL
INPUT
t
PZL
OUTPUT
NO RM A LLY
LO W
SW ITCH
CLOSE D
t
PZH
OUTPUT
NO RM A LLY
HIGH
SW ITCH
OPEN
3.5V
1.5V
0.3V
t
PHZ
0.3V
1.5V
0V
0V
O ctal lin k
1.5V
t
PLZ
0V
3.5V
V
OL
V
OH
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
5
