NSC DS3662N

DS3662
Quad High Speed Trapezoidal™ Bus Transceiver
General Description
Features
The DS3662 is a quad high speed Schottky bus transceiver
intended for use with terminated 120Ω impedance lines. It is
specifically designed to reduce noise in unbalanced transmission systems. The open collector drivers generate precise trapezoidal waveforms with rise and fall times of 15 ns
(typical), which are relatively independent of capacitive loading conditions on the outputs. This reduces noise coupling to
the adjacent lines without any appreciable impact on the
maximum data rate obtainable with high speed bus transceivers. In addition, the receivers use a low pass filter in conjunction with a high speed comparator, to further enhance
the noise immunity. Tightly controlled threshold levels on the
receiver provide equal rejection to both negative and positive
going noise pulses on the bus.
The external termination is intended to be a 180Ω resistor
from the bus to 5V logic supply, together with a 390Ω resistor
from the bus to ground. The bus can be terminated at one or
both ends. A two input NOR gate is provided to disable all
drivers in a package simultaneously.
n Pin to pin functional replacement for DS8641
n Guaranteed AC specifications on noise immunity and
propagation delay over the specified temperature and
supply voltage range
n Temperature insensitive receiver thresholds track bus
logic level
n Trapezoidal bus waveforms reduce noise coupling to
adjacent lines
n Precision receiver thresholds provide maximum noise
immunity and symmetrical response to positive and
negative going pulses
n Open collector driver output allows wire-OR connection
n High speed Schottky technology
n 15 µA typical bus termination current with normal VCC or
with VCC = 0V
n Glitch free power up/down protection on the driver
output
n TTL compatible driver and disable inputs, and receiver
outputs
Block and Connection Diagram
Dual-In-Line Package
DS005803-1
Top View
Order Number DS3662J, DS3662N or DS3662WM
See NS Package Number J16A, N16A or M16B
Trapezoidal™ is a trademark of National Semiconductor Corp.
© 1999 National Semiconductor Corporation
DS005803
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DS3662 Quad High Speed Trapezoidal Bus Transceiver
July 1992
Absolute Maximum Ratings (Note 2)
Lead Temperature (Soldering, 4 sec.)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
260˚C
Recommended Operating
Conditions
Supply Voltage
7V
Input and Output Voltage
5.5V
Storage Temperature Range
−65˚C to +150˚C
Maximum Power Dissipation (Note 1) at 25˚C
Cavity Package
1509 mW
Molded Package
1476 mW
Min
4.75
0
Supply Voltage (VCC)
Temperature Range (TA)
Max
5.25
70
Units
V
˚C
Note 1: Derate cavity package 10.1 mW/˚C above 25˚C; derate molded
package 11.8 mW/˚C above 25˚C.
Electrical Characteristics (Notes 3, 4)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
DRIVER AND DISABLE INPUTS
VIH
Logical “1” Input Voltage
VIL
Logical “0” Input Voltage
II
Logical “1” Input Current
IIH
Logical “1” Input Current
IIL
Logical “0” Input Current
VIN = 5.5V
VIN = 2.4V
VIN = 0.4V
VCL
Input Diode Clamp Voltage
2.0
V
0.8
V
1
mA
40
µA
−1
−1.6
mA
ICLAMP = −12 mA
−0.8
−1.5
V
VDIS = 0.8V, VIN = 2V, IBUS = 100 mA
VIN = 0.8V, VBUS = 4V, VCC = 5.25V
VIN = 0.8V, VBUS = 4V, VCC = 0V
0.6
0.9
V
10
100
µA
100
µA
1.50
V
DRIVER OUTPUT/RECEIVER INPUT
VOLB
Low Level Bus Voltage
IIHB
Maximum Bus Current
IILB
Maximum Bus Current
VIH
High Level Receiver Threshold
VIL
Low Level Receiver Threshold
VIN = 0.8V, VOL = 16 mA
VIN = 0.8V, IOH = −400 µA
1.90
2.4
1.70
1.70
V
RECEIVER OUTPUT
VOH
Logical “1” Output Voltage
VOL
Logical “0” Output Voltage
IOS
Output Short Circuit Current
VIN = 0.8V, VBUS = 0.5V, IOH = −400 µA
VIN = 0.8V, VBUS = 4V, IOL = 16 mA
VDIS = 0.8V, VIN = 0.8V, VBUS = 0.5V,
ICC
Supply Current
VOS = 0V, VCC = 5.25V, (Note 5)
VDIS = 0V, VIN = 2V
−40
3.2
V
0.35
0.5
V
−70
−100
mA
50
90
mA
Switching Characteristics (Notes 3, 4)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
25
35
ns
25
35
ns
Figure 2
20
30
ns
20
30
ns
Figure 3
25
40
ns
25
40
ns
15
20
ns
20
10
ns
PROPAGATION DELAYS
tPLHD
Disable to Bus “1”
tPHLD
Disable to Bus “0”
tPLHB
Driver Input to Bus “1”
tPHLB
Driver Input to Bus “0”
tPLHR
Bus to Logical “1” Receiver Output
tPHLR
Bus to Logical “0” Receiver Output
Figure 1
NOISE IMMUNITY
trB, tfB
Rise and Fall Times (10%–90%)
Figure 2
10
of the Driver Output
tnR
Receiver Noise Rejection
No Response at Receiver
Pulse Width
Output as per Figure 4
Note 2: “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the devices
should be operated at these limits. The tables of “Electrical Characteristics” and “Recommended Operating Conditions” provide conditions for actual device operation.
Note 3: Unless otherwise specified min/max limits apply across the supply and temperature range listed in the table of “Recommended Operating Conditions”. All
typical values are for TA = 25˚C and VCC = 5V.
Note 4: All currents into device pins shown as positive, out of device pins as negative, all voltages referenced to ground unless otherwise noted. All values shown
as max or min on absolute value basis.
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2
Switching Characteristics (Notes 3, 4)
(Continued)
Note 5: Only one output at a time should be shorted.
AC Test Circuits and Switching Waveforms
DS005803-2
DS005803-3
Note: tr = tf = 2.5 ns. Pulse width = 500 ns measured between 1.5V levels. f = 1 MHz.
FIGURE 1. Disable Delays
DS005803-4
DS005803-5
Note: tr = tf = 2.5 ns. Pulse width = 500 ns measured between 1.5V levels. f = 1 MHz.
FIGURE 2. Driver Propagation Delays
DS005803-6
DS005803-7
Note: tr = tf = 15 ns. Pulse width = 500 ns measured between 1.7V levels. f = 1 MHz.
FIGURE 3. Receiver Propagation Delays
3
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AC Test Circuits and Switching Waveforms
(Continued)
DS005803-8
DS005803-10
DS005803-9
tr = tf = 2.5 ns
tr = tf = 2.5 ns
(b) Receiver Output (VO) to Remain Less than 0.7V
(a) Receiver Output (VO) to Remain Greater than 2.2V
FIGURE 4. Receiver Noise Immunity: “No Response at Output” Input Waveforms
Typical Application
DS005803-11
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4
Physical Dimensions
inches (millimeters) unless otherwise noted
Ceramic Dual-In-Line Package (J)
Order Number DS3662J
NS Package Number J16A
16-Lead Molded Small Outline Package (M)
Order Number DS3662WM
NS Package Number M16B
5
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DS3662 Quad High Speed Trapezoidal Bus Transceiver
Physical Dimensions
inches (millimeters) unless otherwise noted (Continued)
Molded Dual-In-Line Package (N)
Order Number DS3662N
NS Package Number N16A
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