MILITARY AND INDUSTRIAL TEMPERATURE RANGES
IDT54/74FCT245T/AT/CT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
1
SEPTEMBER 2009MILITARY AND INDUSTRIAL TEMPERATURE RANGES
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
© 2009 Integrated Device Technology, Inc. DSC-5510/6
FEATURES:
• Std., A, and C grades
• Low input and output leakage ≤≤
≤≤
≤1µA (max.)
• CMOS power levels
• True TTL input and output compatibility:
–VOH = 3.3V (typ.)
–VOL = 0.3V (typ.)
• High Drive outputs (-15mA IOH, 64mA IOL)
• Meets or exceeds JEDEC standard 18 specifications
• Military product compliant to MIL-STD-883, Class B and DESC
listed (dual marked)
• Power off disable outputs permit "live insertion"
• Available in the following packages:
– Industrial: SOIC, SSOP, QSOP, TSSOP
– Military: CERDIP, LCC
FUNCTIONAL BLOCK DIAGRAM
IDT54/74FCT245T/AT/CT
FAST CMOS OCTAL
BIDIRECTIONAL
TRANSCEIVER
DESCRIPTION:
The IDT octal bidirectional transceivers are built using an advanced dual
metal CMOS technology. The FCT245T 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
B0
0
T/R
OE
A
B1
1
A
B2
2
A
B3
3
A
B4
4
A
B5
5
A
B6
6
A
B7
7
MILITARY AND INDUSTRIAL TEMPERATURE RANGES
2
IDT54/74FCT245T/AT/CT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
PIN CONFIGURATION
Symbol Description Max Unit
VTERM(2) Terminal Voltage with Respect to GND –0.5 to +7 V
VTERM(3) Terminal Voltage with Respect to GND –0.5 to VCC+0.5 V
TSTG Storage Temperature –65 to +150 °C
IOUT 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.
Pin Names Description
OE Output Enable Inputs (Active LOW)
T/RTransmit/Recieve Input
A0 - A7Side A Inputs or 3-State Outputs
B0 - B7Side B Inputs or 3-State Outputs
PIN DESCRIPTION
Symbol Parameter(1) Conditions Typ. Max. Unit
CIN Input Capacitance VIN = 0V 6 10 pF
COUT Output Capacitance VOUT = 0V 8 12 pF
CAPACITANCE (TA = +25°C, F = 1.0MHz)
NOTE:
1. This parameter is measured at characterization but not tested.
NOTE:
1 . H = HIGH Voltage Level
X = Don’t Care
L = LOW Voltage Level
Z = High Impedance
FUNCTION TABLE(1)
Inputs
OE T/ROutputs
L L Bus B Data to Bus A
L H Bus A Data to Bus B
H X High Z State
CERDIP/ SOIC/ SSOP/ QSOP/ TSSOP
TOP VIEW
2
3
1
16
15
14
11
19
18
20
17
13
12
5
6
7
4
8
9
10
A
2
A
0
A
1
V
CC
A
3
A
6
A
4
A
5
A
7
GND
OE
B
2
B
0
B
1
B
3
B
6
B
4
B
5
B
7
T/R
1
23
4
5
7
9
6
8
10 11 12 13
14
15
16
17
18
1920
B
2
B
0
B
1
B
3
B
4
A
1
A
0
A
7
GND
B
7
B
6
B
5
T/R
V
CC
OE
INDEX
A
2
A
3
A
6
A
4
A
5
LCC
TOP VIEW
MILITARY AND INDUSTRIAL TEMPERATURE RANGES
IDT54/74FCT245T/AT/CT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
3
Symbol Parameter Test Conditions(1) Min. Typ.(2) Max. Unit
VIH Input HIGH Level Guaranteed Logic HIGH Level 2 — — V
VIL Input LOW Level Guaranteed Logic LOW Level — — 0.8 V
IIH Input HIGH Current(4) VCC = Max. VI = 2.7V — — ±1µA
IIL Input LOW Current(4) VCC = Max. VI = 0.5V — — ±1µA
IOZH High Impedance Output Current VCC = Max VO = 2.7V — — ±1µA
IOZL (3-State output pins)(4) VO = 0.5V — — ±1
IIInput HIGH Current(4) VCC = Max., VI = VCC (Max.) — — ±1µA
VIK Clamp Diode Voltage VCC = Min, IIN = -18mA — –0.7 –1.2 V
VHInput Hysteresis — — 200 — mV
ICC Quiescent Power Supply Current VCC = Max., VIN = GND or VCC — 0.01 1 mA
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: TA = –40°C to +85°C, VCC = 5.0V ±5%; Military: TA = –55°C to +125°C, VCC = 5.0V ±10%
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 VCC = 5.0V, +25°C 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 ±5µA at TA = –55°C.
Symbol Parameter Test Conditions(1) Min. Typ.(2) Max. Unit
VOH Output HIGH Voltage VCC = Min IOH = –6mA MIL 2.4 3.3 —
VIN = VIH or VIL IOH = –8mA IND V
IOH = –12mA MIL 2 3 —
IOH = –15mA IND
VOL Output LOW Voltage VCC = Min IOL = 4 8 m A M I L — 0.3 0.55 V
VIN = VIH or VIL IOL = 64mA IND
IOS Short Circuit Current VCC = Max., VO = GND(3) –60 –120 –225 mA
OUTPUT DRIVE CHARACTERISTICS
MILITARY AND INDUSTRIAL TEMPERATURE RANGES
4
IDT54/74FCT245T/AT/CT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
Symbol Parameter Test Conditions(1) Min. Typ.(2) Max. Unit
ΔICC Quiescent Power Supply Current VCC = Max. — 0.5 2 mA
TTL Inputs HIGH VIN = 3.4V(3)
ICCD Dynamic Power Supply VCC = Max. VIN = VCC — 0.15 0.25 mA/
Current(4) Outputs Open VIN = GND M Hz
OE = T/R = GND
One Input Toggling
50% Duty Cycle
ICTotal Power Supply Current(6) VCC = Max. VIN = VCC — 1.5 3.5 mA
Outputs Open VIN = GND
fi = 10MHz
50% Duty Cycle VIN = 3.4V — 1.8 4.5
OE = T/R = GND VIN = GND
One Bit Toggling
VCC = Max. VIN = VCC —36
(5)
Outputs Open VIN = GND
fi = 2.5MHz
50% Duty Cycle VIN = 3.4V — 5 14(5)
OE = T/R = GND VIN = GND
Eight 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 VCC = 5.0V, +25°C ambient.
3. Per TTL driven input; (VIN = 3.4V). All other inputs at VCC 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 ΔICC formula. These limits are guaranteed but not tested.
6. IC = IQUIESCENT + IINPUTS + IDYNAMIC
IC = ICC + ΔICC DHNT + ICCD (fCP/2+ fiNi)
ICC = Quiescent Current
ΔICC = Power Supply Current for a TTL High Input (VIN = 3.4V)
DH = Duty Cycle for TTL Inputs High
NT = Number of TTL Inputs at DH
ICCD = Dynamic Current caused by an Input Transition Pair (HLH or LHL)
fCP = Clock Frequency for Register Devices (Zero for Non-Register Devices)
fi = Output Frequency
Ni = Number of Outputs at fi
All currents are in milliamps and all frequencies are in megahertz.
POWER SUPPLY CHARACTERISTICS
MILITARY AND INDUSTRIAL TEMPERATURE RANGES
IDT54/74FCT245T/AT/CT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
5
74FCT245AT 74FCT245CT
Symbol Parameter Condition(1) Min.(2) Max. Min.(2) Max. Unit
tPLH Propagation Delay CL = 50pF 1.5 4.6 1.5 4.1 ns
tPHL A to B, B to A R L = 500Ω
tPZH Output Enable Time 1.5 6.2 1.5 5.8 ns
tPZL OE to A or B
tPHZ Output Disable Time 1.5 5 1.5 4.8 ns
tPLZ OE to A or B
tPZH Output Enable Time 1.5 6.2 1.5 5.8 ns
tPZL T/R to A or B(3)
tPHZ Output Disable Time 1.5 5 1.5 4.8 ns
tPLZ T/R to A or B(3)
SWITCHING CHARACTERISTICS OVER OPERATING RANGE - INDUSTRIAL
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.
54FCT245T 54FCT245AT 54FCT245CT
Symbol Parameter Condition(1) Min.(2) Max. Min.(2) Max. Min.(2) Max. Unit
tPLH Propagation Delay CL = 50pF 1.5 7.5 1.5 4.9 1.5 4.5 ns
tPHL A to B, B to A RL = 500Ω
tPZH Output Enable Time 1.5 10 1.5 6.5 1.5 6.2 ns
tPZL OE to A or B
tPHZ Output Disable Time 1.5 10 1.5 6 1.5 5.2 ns
tPLZ OE to A or B
tPZH Output Enable Time 1.5 10 1.5 6.5 1.5 6.2 ns
tPZL T/R to A or B(3)
tPHZ Output Disable Time 1.5 10 1.5 6 1.5 5.2 ns
tPLZ T/R to A or B(3)
SWITCHING CHARACTERISTICS OVER OPERATING RANGE - MILITARY
MILITARY AND INDUSTRIAL TEMPERATURE RANGES
6
IDT54/74FCT245T/AT/CT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
Pulse
Generator
R
T
D.U.T
.
V
CC
V
IN
C
L
V
OUT
50pF 500W
500W
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.
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; tF ≤ 2.5ns; tR ≤ 2.5ns.
Test Switch
Open Drain
Disable Low Closed
Enable Low
All Other Tests Open
SWITCH POSITION
DEFINITIONS:
CL = Load capacitance: includes jig and probe capacitance.
RT = Termination resistance: should be equal to ZOUT of the Pulse Generator.
MILITARY AND INDUSTRIAL TEMPERATURE RANGES
IDT54/74FCT245T/AT/CT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
7
ORDERING INFORMATION
XX
Temp. Range
FCT XXXX
Device Type
XX
Package
X
Process
Fast CMOS Octal Bidirectional Transceiver
245T
245AT
245CT
SOG
PYG
QG
PGG
Industrial Options
Small Outline IC - Green
Shrink Small Outline Package - Green
Quarter-size Small Outline Package - Green
Thin Shrink Small Outline Package - Green
D
L
Military Options
CERDIP
Leadless Chip Carrier
Blank
B
Industrial
MIL-STD-883, Class B
54
74 55C to +125C
40C to +85C
CORPORATE HEADQUARTERS for SALES: for Tech Support:
6024 Silver Creek Valley Road 800-345-7015 or 408-284-8200 logichelp@idt.com
San Jose, CA 95138 fax: 408-284-2775
www.idt.com
Datasheet Document History
09/29/09 Pg. 7 Updated the ordering information by removing the "IDT" notation and non RoHS part.
