PI74LPT245
3.3V 8-BIT BIDIRECTIONAL TRANSCEIVER
1
PS2059A 01/15/97
12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Product Description
Pericom Semiconductor's PI74LPT series of logic circuits are pro-
duced in the Company's advanced 0.6 micron CMOS technology,
achieving industry leading speed grades.
The PI74LPT245 is an 8-bit bidirectional transceiver designed for
asynchronous two-way communication between data buses. The
transmit/receive input pin (T/R) 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.
The PI74LPT245 can be driven from either 3.3V or 5.0V devices
allowing this device to be used as a translator in a mixed
3.3/5.0V system.
Logic Block Diagram
12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012
12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012
PI74LPT245
Fast CMOS 3.3V 8-Bit
Bidirectional Transceiver
B
0
A
0
OE
T/
R
B
1
A
1
B
2
A
2
B
3
A
3
B
4
A
4
B
5
A
5
B
6
A
6
B
7
A
7
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
VCC
OE
B0
B1
B2
B3
B4
B5
B6
B7
T/
R
A0
A1
A2
A3
A4
A5
A6
A7
GND
20-PIN
L20
Q20
R20
S20
Product Pin Configuration
Product Pin Description
Pin Name
Description
OE
3-State Output Enable
Inputs (Active LOW)
T/R
Direction Control Input
A7-A0
Side A Inputs or
3-State Outputs
B7-B0
Side B Inputs or
3-State Outputs
GND
Ground
V
CC
Power
Inputs
(1)
OE
T/R
Outputs
(1)
L
L
Bus B Data to Bus A
L
H
Bus A Data to Bus B
H
X
High StateZ
Truth Table
Note:
1. H = High Voltage Level, X = Don't Care,
L = Low Voltage Level, Z = High Impedance
Product Features
Compatible with LCXTM and LVTTM families of products
Supports 5V Tolerant Mixed Signal Mode Operation
Input can be 3V or 5V
Output can be 3V or connected to 5V bus
Advanced Low Power CMOS Operation
Excellent output drive capability:
Balanced drives (24 mA sink and source)
Low ground bounce outputs
Hysteresis on all inputs
Industrial operating temperature range: 40C to +85C
Packages available:
20-pin 173 mil wide plastic TSSOP (L)
20-pin 150 mil wide plastic QSOP (Q)
20-pin 150 mil wide plastic TQSOP (R)
20-pin 300 mil wide plastic SOIC (S)
T/
R
T/
R
OE
PI74LPT245
3.3V 8-BIT BIDIRECTIONAL TRANSCEIVER
2
PS2059A 01/15/97
12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Maximum Ratings
(Above which the useful life may be impaired. For user guidelines, not tested.)
Note:
Stresses greater than those listed under 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 condi-
tions above those indicated in the operational sec-
tions of this specification is not implied. Exposure to
absolute maximum rating conditions for extended
periods may affect reliability.
DC Electrical Characteristics
(Over the Operating Range, T
A
= 40C to +85C, V
CC
= 2.7V to 3.6V)
Parameters
Description
Test Conditions
(1)
Min.
Typ
(2)
Max.
Units
V
IH
Input HIGH Voltage (Input pins)
Guaranteed Logic HIGH Level
2.2
--
5.5
V
Input HIGH Voltage (I/O pins)
2.0
--
5.5
V
V
IL
Input LOW Voltage
Guaranteed Logic LOW Level
0.5
--
0.8
V
(Input and I/O pins)
I
IH
Input HIGH Current (Input pins)
V
CC
= Max.
V
IN
= 5.5V
--
--
1
A
Input HIGH Current (I/O pins)
V
CC
= Max.
V
IN
= V
CC
--
--
1
A
I
IL
Input LOW Current (Input pins)
V
CC
= Max.
V
IN
= GND
--
--
1
A
Input LOW Current (I/O pins)
V
CC
= Max.
V
IN
= GND
--
--
1
A
I
OZH
High Impedance Output Current
V
CC
= Max.
V
OUT
= 5.5V
--
--
1
A
I
OZL
(3-State Output pins)
V
CC
= Max.
V
OUT
= GND
--
--
1
A
V
IK
Clamp Diode Voltage
V
CC
= Min., I
IN
= 18 mA
--
0.7
1.2
V
I
ODH
Output HIGH Current
V
CC
= 3.3V, V
IN
= V
IH
or V
IL
, V
O
= 1.5V
(3)
36
60
110
mA
I
ODL
Output LOW Current
V
CC
= 3.3V, V
IN
= V
IH
or V
IL
, V
O
= 1.5V
(3)
50
90
200
mA
V
OH
Output HIGH Voltage
V
CC
= Min.
I
OH
= 0.1 mA Vcc-0.2
--
--
V
V
IN
= V
IH
or V
IL
I
OH
= 3 mA
2.4
3.0
--
V
V
CC
= 3.0V,
I
OH
= 8 mA
2.4
(5)
3.0
--
V
V
IN
= V
IH
or V
IL
I
OH
= 24 mA
2.0
--
--
V
OL
Output LOW Voltage
V
CC
= Min.
I
OL
= 0.1 mA
--
--
0.2
V
V
IN
= V
IH
or V
IL
I
OL
= 16 mA
--
0.2
0.4
V
I
OL
= 24 mA
--
0.3
0.5
V
I
OS
Short Circuit Current
(4)
V
CC
= Max.
(3)
, V
OUT
= GND
60
85
240
mA
I
OFF
Power Down Disable
V
CC
= 0V, V
IN
or V
OUT
4.5V
--
--
100
A
V
H
Input Hysteresis
--
150
--
mV
Capacitance
(T
A
= 25C, f = 1 MHz)
Parameters
(1)
Description
Test Conditions
Typ.
Max.
Units
C
IN
Input Capacitance
V
IN
= 0V
4.5
6
pF
C
OUT
Output Capacitance
V
OUT
= 0V
5.5
8
pF
Notes:
1. For Max. or Min. conditions, use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at Vcc = 3.3V, +25C ambient and maximum loading.
3. Not more than one output should be shorted at one time. Duration of the test should not exceed one second.
4. This parameter is guaranteed but not tested.
5. V
OH
= V
CC
0.6V at rated current.
Note:
1. This parameter is determined by device characterization but is not production tested.
Storage Temperature ............................................................. 55C to +125C
Ambient Temperature with Power Applied ............................ 40C to +85C
Supply Voltage to Ground Potential (Inputs & Vcc Only) ...... 0.5V to +7.0V
Supply Voltage to Ground Potential (Outputs & D/O Only) .. 0.5V to +7.0V
DC Input Voltage .................................................................... 0.5V to +7.0V
DC Output Current .............................................................................. 120 mA
Power Dissipation .................................................................................... 1.0W
PI74LPT245
3.3V 8-BIT BIDIRECTIONAL TRANSCEIVER
3
PS2059A 01/15/97
12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Power Supply Characteristics
Parameters Description
Test Conditions
(1)
Min.
Typ
(2)
Max.
Units
I
CC
Quiescent Power Supply Current
V
CC
= Max.
V
IN
= GND or V
CC
0.1
10
A
I
CC
Quiescent Power Supply Current
V
CC
= Max.
V
IN
= V
CC
0.6V
(3)
2.0
30
A
TTL Inputs HIGH
I
CCD
Dynamic Power Supply
(4)
V
CC
= Max.,
V
IN
= V
CC
50
75
A/
Outputs Open
V
IN
= GND
MHz
OE = GND
One Bit Toggling
50% Duty Cycle
I
C
Total Power Supply
V
CC
= Max.,
V
IN
= V
CC
0.6V
0.6
2.3
mA
Current
(6)
Outputs Open
V
IN
= GND
f
I
= 10 MH
Z
50% Duty Cycle
OE = GND
One Bit Toggling
V
CC
= Max.,
V
IN
= V
CC
0.6V
2.1
4.7
(5)
Outputs Open
V
IN
= GND
f
I
= 2.5 MH
Z
50% Duty Cycle
OE = GND
8 Bits Toggling
Notes:
1. For Max. or Min. conditions, use appropriate value specified under Electrical Characteristics for the applicable device.
2. Typical values are at Vcc = 3.3V, +25C ambient.
3. Per TTL driven input; 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 the Icc 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
CCL
, I
CCH
and I
CCZ
)
I
CC
= Power Supply Current for a TTL High Input
D
H
= Duty Cycle for TTL Inputs High
N
T
= Number of TTL Inputs at D
H
I
CCD
= Dynamic Current Caused by an Input Transition Pair (HLH or LHL)
f
CP
= Clock Frequency for Register Devices (Zero for Non-Register Devices)
N
CP
= Number of Clock Inputs at f
CP
f
I
= Input Frequency
N
I
= Number of Inputs at f
I
All currents are in milliamps and all frequencies are in megahertz.
PI74LPT245
3.3V 8-BIT BIDIRECTIONAL TRANSCEIVER
4
PS2059A 01/15/97
12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012
Notes:
1. Propagation Delays and Enable/Disable times are with Vcc = 3.3V 0.3V, normal range. For Vcc = 2.7V, extended range, all
Propagation Delays and Enable/Disable times should be degraded by 20%.
2. See test circuit and wave forms.
3. Minimum limits are guaranteed but not tested on Propagation Delays.
4. This parameter is guaranteed but not production tested.
5. Skew between any two outputs, of the same package, switching in the same direction. This parameter is guaranteed by design.
Switching Characteristics over Operating Range
(1)
LPT245
LPT245A
LPT245C
Com.
Com.
Com.
Parameters
Description
Conditions
(2)
Min.
(3)
Max.
Min.
(3)
Max.
Min.
(3)
Max.
Units
t
PLH
Propagation Delay
C
L
= 50 pF
1.5
7.0
1.5
4.6
1.5
4.1
ns
t
PHL
A to B, B to A
R
L
= 500
t
PZH
Output Enable Time
1.5
8.5
1.5
6.2
1.5
5.8
ns
t
PZL
OE to A or B
t
PHZ
Output Disable Time
(4)
1.5
7.5
1.5
5.0
1.5
4.8
ns
t
PLZ
OE to A or B
t
PZH
Output Enable Time
1.5
8.5
1.5
6.2
1.5
5.8
ns
t
PZL
T/R to A or B
t
PHZ
Output Disable Time
(4)
1.5
7.5
1.5
5.0
1.5
4.8
ns
t
PLZ
T/R to A or B
t
SK
(o)
Output Skew
(5)
0.5
0.5
0.5
ns
Pericom Semiconductor Corporation
2380 Bering Drive San Jose, CA 95131 1-800-435-2336 Fax (408) 435-1100 http://www.pericom.com
PDF 
ZIP