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Integrated Device Technology, Inc.
MILITARY AND COMMERCIAL TEMPERATURE RANGES
AUGUST 1996
1996 Integrated Device Technology, Inc.
5.10
DSC-2547/8
1
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
IDT54/74FCT16501AT/CT/ET
IDT54/74FCT162501AT/CT/ET
IDT54/74FCT162H501AT/CT/ET
FAST CMOS
18-BIT REGISTERED
TRANSCEIVER
CMOS technology. These high-speed, low-power 18-bit reg-
istered bus transceivers combine D-type latches and D-type
flip-flops to allow data flow in transparent, latched and clocked
modes. Data flow in each direction is controlled by output-
enable (OEAB and
OEBA
), latch enable (LEAB and LEBA)
and clock (CLKAB and CLKBA) inputs. For A-to-B data flow,
the device operates in transparent mode when LEAB is HIGH.
When LEAB is LOW, the A data is latched if CLKAB is held at
a HIGH or LOW logic level. If LEAB is LOW, the A bus data
is stored in the latch/flip-flop on the LOW-to-HIGH transition of
CLKAB. OEAB is the output enable for the B port. Data flow
from the B port to the A port is similar but requires using
OEBA
,
LEBA and CLKBA. Flow-through organization of signal pins
simplifies layout. All inputs are designed with hysteresis for
improved noise margin.
The FCT16501AT/CT/ET are ideally suited for driving
high-capacitance loads and low-impedance backplanes. The
output buffers are designed with power off disable capability
to allow "live insertion" of boards when used as backplane
drivers.
The FCT162501AT/CT/ET have balanced output drive
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
FCT162501AT/CT/ET are plug-in replacements for the
FCT16501AT/CT/ET and ABT16501 for on-board bus inter-
face applications.
The FCT162H501AT/CT/ET have "Bus Hold" which re-
tains the input's last state whenever the input goes to high
impedance. This prevents "floating" inputs and eliminates the
need for pull-up/down resistors.
DESCRIPTION:
The FCT16501AT/CT/ET and FCT162501AT/CT/ET 18-
bit registered transceivers are built using advanced dual metal
FUNCTIONAL BLOCK DIAGRAM
2547 drw 01
OEBA
CLKBA
LEBA
OEAB
CLKAB
LEAB
B
1
A
1
C
C
D
D
D
C
D
C
TO 17 OTHER CHANNELS
FEATURES:
Common features:
–
0.5 MICRON CMOS Technology
–
High-speed, low-power CMOS replacement for
ABT functions
–
Typical t
SK
(o) (Output Skew) < 250ps
–
Low input and output leakage
≤
1
μ
A (max.)
–
ESD > 2000V per MIL-STD-883, Method 3015;
> 200V using machine model (C = 200pF, R = 0)
–
Packages include 25 mil pitch SSOP, 19.6 mil pitch
TSSOP, 15.7 mil pitch TVSOP and 25 mil pitch Cerpack
–
Extended commercial range of -40
°
C to +85
°
C
Features for FCT16501AT/CT/ET:
–
High drive outputs (-32mA I
OH
, 64mA I
OL
)
–
Power off disable outputs permit “l(fā)ive insertion”
–
Typical V
OLP
(Output Ground Bounce) < 1.0V at
V
CC
= 5V, T
A
= 25
°
C
Features for FCT162501AT/CT/ET:
–
Balanced Output Drivers:
±
24mA (commercial),
±
16mA (military)
–
–
Reduced system switching noise
Typical V
OLP
(Output Ground Bounce) < 0.6V at
V
CC
= 5V,T
A
= 25
°
C
Features for FCT162H501AT/CT/ET:
–
Bus Hold retains last active bus state during 3-state
–
Eliminates the need for external pull up resistors