DS3890 BTL Octal Trapezoidal Driver DS3892 BTL Octal TRI-STATE Receiver
January 1996
DS3890 BTL Octal Trapezoidal Driver
DS3892 BTL Octal TRI-STATE Receiver
General Description
The DS3890 and DS3898 are designed specifically to over-
come problems associated with driving densely populated
backplanes These products provide significant improve-
ment in both speed and data integrity in comparison to con-
ventional bus drivers and receivers Their low output capaci-
tance low voltage swing and noise immunity features make
them ideal for driving low impedance busses with minimum
power dissipation
The DS3890 features an open collector outputs that gener-
ate precise trapezoidal waveforms with typical rise and fall
times of 6 ns which are relatively independent of capacitive
loading conditions These controlled output characteristics
significantly reduce noise coupling to adjacent lines
To minimize bus loading the DS3890 also features a
schottky diode in series with the open collector outputs that
isolates the driver output capacitance in the disabled state
With this type of configuration the output low voltage is typi-
cally 鈥樷€?V鈥欌€?The output high level is intended to be 2 volts
This is achieved by terminating the bus with a pull up resis-
tor Both devices can drive an equivalent DC load of 18 5X
(or greater) in the defined configuration
(General Description to be continued)
Features
Y
Y
Y
Y
Y
Y
Y
Y
Y
Driver output capacitance less than 5 pF
1 volt bus signal reduces power consumption
Trapezoidal driver waveforms (t
r
t
f
typically 6 ns) re-
duces noise coupling to adjacent lines
Precise receiver threshold track the bus logic high level
to maximize noise immunity in both logic high ahd low
states
Open collector driver output allows wire-or connection
Advanced low power schottky technology
Glitch free power up down protection
TTL compatible driver and control inputs and receiver
output
BTL compatible
Logic and Connection Diagrams
DS3890 Octal Trapezoidal Driver
DS3892 Octal TRI-STATE Receiver
TL F 8700 鈥?1
TL F 8700 鈥?2
Order Numbers DS3892M DS3890N or DS3892N
See NS Package Number M20B or N20A
TRI-STATE is a registered trademark of National Semiconductor Corporation
C
1996 National Semiconductor Corporation
TL F 8700
RRD-B30M36 Printed in U S A
http
www national com
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