TLF8753

June 1990

DP8216DP8216MDP8226DP8226M

4-Bit Bidirectional Bus Transceivers

General Description

The DP8216DP8216M and DP8226DP8226M are 4-bit bi-

directional bus drivers to use in bus oriented applications

The

non-inverting

DP8216DP8216M

and

inverting

DP8226DP8226M drivers are provided for flexibility in sys-

tem design

Each buffered line of the four-bit drivers consists of two

separate buffers that are TRI-STATE

to achieve direct bus

interface and bidirectional capability On one side of the

driver the output of one buffer and the input of another are

tied together (DB) this side is used to interface to the sys-

tem side components such as memories IO etc because

its interface is TTL compatible and it has high driver (50

mA) On the other side of the driver the inputs and outputs

are separated to provide maximum flexibility Of course

they can be tied together so that the driver can be used to

buffer a true bidirectional bus The DO outputs on this side

of the driver have a special high voltage output drive capa-

bility so that direct interface to the 8080 type CPUs is

achieved with an adequate amount of noise immunity

The CS input is a device enable When it is ‘‘high’’ the out-

put drivers are all forced to their high-impedance state

When it is a ‘‘low’’ the device is enabled and the direction of

the data flow is determined by the DIEN input

The DIEN input controls the direction of data flow which is

accomplished by forcing one of the pair of buffers into its

high-impedance state and allowing the other to transmit its

data A simple two-gate circuit is used for this function

Features

Y

Data bus buffer driver to 8080 type CPUs

Y

Low input load current025 mA maximum

Y

High output drive capability for driving system data

bus50 mA at 05V

Y

Power up-down protection

Y

DP8216DP8216M have non-inverting outputs

Y

DP8226DP8226M have inverting outputs

Y

Output high voltage compatible with direct interface to

MOS

Y

TRI-STATE outputs

Y

Advanced Schottky processing

Y

Available in military and commercial temperature

Logic Diagrams

DP8216DP8216M

TLF8753 – 1

DP8226DP8226M

TLF8753 – 2

TRI-STATE

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C1995 National Semiconductor Corporation

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