TLF8700

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 ‘‘1V’’ 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 185X

(or greater) in the defined configuration

(General Description to be continued)

Features

Y

Driver output capacitance less than 5 pF

Y

1 volt bus signal reduces power consumption

Y

duces noise coupling to adjacent lines

Y

Precise receiver threshold track the bus logic high level

to maximize noise immunity in both logic high ahd low

states

Y

Open collector driver output allows wire-or connection

Y

Advanced low power schottky technology

Y

Glitch free power updown protection

Y

TTL compatible driver and control inputs and receiver

output

Y

BTL compatible

Logic and Connection Diagrams

DS3890 Octal Trapezoidal Driver

TLF8700 – 1

DS3892 Octal TRI-STATE Receiver

TLF8700 – 2

Order Numbers DS3892M DS3890N or DS3892N

See NS Package Number M20B or N20A

TRI-STATE

is a registered trademark of National Semiconductor Corporation

C1996 National Semiconductor Corporation

RRD-B30M36Printed in U S A

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