NSC DS3862WMX, DS3862WM, DS3862N Datasheet

DS3862
Octal High Speed Trapezoidal Bus Transceiver

General Description

The DS3862 is an octal 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 9 ns
(typical), which are relatively independentofcapacitiveload­ing 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.

Features

n Guaranteed A.C. specifications on noise immunity and

propagation delay over the specified temperature and
supply voltage range

n Temperature insensitive receiver thresholds track bus

logic level and respond symmetrically to positive and
negative going pulses

n Trapezoidal bus waveforms reduce noise coupling to

adjacent lines

n Open collector driver output allows wire-or connection
n Advanced low power schottky technology
n Glitch free power up/down protection on driver and

receiver outputs

n TTL compatible driver and control inputs, and receiver

outputs

n Control logic is the same as the DS3896

Logic and Connection Diagram

DS008539-1

Order Number DS3862J, DS3862N or DS3862WM

See NS Package Number J20A, N20A or M20B

February 1995

DS3862 Octal High Speed Trapezoidal Bus Transceiver

© 1999 National Semiconductor Corporation DS008539 www.national.com

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

Supply Voltage 6V
Control Input Voltage 5.5V
Driver Input and Receiver Output 5.5V
Receiver Input and Driver Output 5.5V
Power Dissipation 1400 mW

Storage Temperature Range −65˚C to +150˚C
Lead Temperature (Soldering, 4 seconds) 260˚C

Recommended Operating
Conditions

Min Max Units

Supply Voltage,V

CC

4.75 5.25 V

Operating Free Air Temperature 0 70 ˚C

Electrical Characteristics (Notes 2, 3)

0˚C ≤ TA≤ 70˚C, 4.75V ≤ VCC≤ 5.25V unless otherwise specified

Symbol Parameter Conditions Min Typ Max Units
Driver and Control Inputs:

V

IH

Logical “1” Input Voltage 2.0 V

V

IL

Logical “0” Input Voltage 0.8 V

I

I

Logical “1” Input Current An=V

CC

1mA

I

IH

Logical “1” Input Current An=2.4V 40 µA

I

IHC

Logical “1” Input Current CD=T/R=2.4V 80 µA

I

IL

Logical “0” Input Current An=0.4V −1 −1.6 mA

I

ILC

CD & T/R Logical “0” Input Current CD=T/R=0.4V −180 −400 µA

V

CL

Input Diode Clamp Voltage Iclamp=−12 mA −0.9 −1.5 V

Driver Output/Receiver Input

V

OLB

Low Level Bus Voltage An=T/R=2V, Ibus=100 mA 0.6 0.9 V

I

IHB

Logical “1” Bus Current An=0.8V, Bn=4V, V

CC

=

5.25V and 0V 10 100 µA

I

ILB

Logical “0” Bus Current An=0.8V, Bn=0V, V

CC

=

5.25V and 0V 100 µA

V

TH

Input Threshold V

CC

=

5V 1.5 1.7 1.9 V

Receiver Output

V

OH

Logical “1” Output Voltage Bn=0.9V, I

oh

=

− 400µA 2.4 3.2 V

V

OL

Logical “0” Output Voltage Bn=4V, I

ol

=

16 mA 0.35 0.5 V

I

OS

Output Short Circuit Current Bn=0.9V −20 −70 −100 mA

I

CC

Supply Current V

CC

=

5.25V 90 135 mA

Note 1: “Absolute Maximum Ratings” are those beyond which the safety of the device cannot be guaranteed. They are not meant to imply that device should be op­erated at these limits. The table of “Electrical Characteristics” provide conditions for actual device operation.

Note 2: All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device ground unless otherwise specified.
Note 3: All typicals are given for V

CC

=

5V and T

A

=

25˚C.

Switching Characteristics

0˚C ≤ TA≤ 70˚C, 4.75V ≤ VCC≤ 5.25V unless otherwise specified

Symbol Parameter Conditions Min Typ Max Units

Driver:

t

DLH

An to Bn CD=0.8V, T/R=2.0V, VL=5V (

Figure 1

) 12 20 ns

t

DHL

12 20 ns

t

DLHC

CD to Bn An=T/R=2.0V, VL=5V, (

Figure 1

) 12 20 ns

t

DHLC

15 25 ns

t

DLHT

T/R to Bn VCI=An, VC=5V, (

Figure 2

)2030ns

t

DHLT

CD=0.8V, RC=390Ω,CL=30 pF 25 40 ns
RL1=91Ω, RL2=200Ω,VL=5V

t

R

Driver Output Rise Time CD=0.8V, T/R=2V, VL=5V (

Figure 1

) 4 9 20 ns

t

F

Driver Output Fall Time 4 9 20 ns

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Switching Characteristics (Continued)

0˚C ≤ TA≤ 70˚C, 4.75V ≤ VCC≤ 5.25V unless otherwise specified

Symbol Parameter Conditions Min Typ Max Units

Receiver:

t

RLH

Bn to An CD=0.8V, T/R=0.8V (

Figure 3

) 15 25 ns

t

RHL

15 25 ns

t

RLZC

CD to An Bn=2.0V, T/R=0.8V, CL=5pF 15 25 ns

RL1=390Ω, RL2=NC, VL=5V (

Figure 4

)

t

RZLC

Bn=2.0V, T/R=0.8V, CL=30 pF 10 20 ns
RL1=390Ω, RL2=1.6K, VL=5V (

Figure 4

)

t

RHZC

Bn=0.8V, T/R=0.8V, VL=0V, 510 ns
RL1=390Ω, RL2=NC, CL=5pF (

Figure 4

)

t

RZHC

Bn=0.8V, T/R=0.8V, VL=0V, 815 ns
RL1=NC, RL2=1.6K, CL=30 pF (

Figure 4

)

t

RLZT

T/R to An VCI=Bn, VC=3.4V, RC=39Ω 20 30 ns

CD=0.8V, VL=5V, RL1=390Ω,
RL2=NC, CL=5pF (

Figure 2

)

t

RZLT

VCI=Bn, VC=3.4V, RC=39Ω,3045ns
CD=0.8V, VL=5V, RL1=390Ω,
RL2=1.6K, CL=30 pF (

Figure 2

)

t

RHZT

VCI=Bn, VC=0V, RC=39Ω 510 ns
CD=0.8V, VL=0V, RL1=390Ω,
RL2=NC, CL=5pF (

Figure 2

)

t

RZHT

VCI=Bn, VC=0V, RC=39Ω,1020ns
CD=0.8V, VL=0V, RL1=NC
RL2=1.6K, CL=30 pF (

Figure 2

)

t

NR

Receiver Noise Rejection (

Figure 5

) 9 12 ns

Pulse Width

Note: NC means open

Switching Waveforms

DS008539-2

Note: t

r

=

t

f

≤ 5 ns from 10%to 90

%

FIGURE 1. Driver Propagation Delays

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