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HI-1567, HI-1568
PIN DESCRIPTIONS
FUNCTIONAL DESCRIPTION
PIN
SYMBOL
FUNCTION
DESCRIPTION
1
2
3
4
5
6
7
8
VDDA
BUSA
BUSA
power supply
analog output
analog output
digital input
power supply
power supply
analog output
analog output
digital input
power supply
digital output
+5 volt power for channel A
MIL-STD-1533 bus driver A, positive signal
MIL-STD-1553 bus driver A, negative signal
Receiver A enable. If low, forces RXA and
Ground for channel A
+5 volt power for channel B
MIL-STD-1533 bus driver B, positive signal
MIL-STD-1553 bus driver B, negative signal
Receiver B enable. If low, forces RXB and
Ground for channel B
Receiver B output, inverted
RXENA
GNDA
VDDB
BUSB
BUSB
low (HI-1567) or High (HI-1568)
9
RXENB
GNDB
RXB
10
11
12
13
14
15
16
17
18
19
15
RXB
TXINHB
TXB
TXB
RXA
RXA
TXINHA
TXA
TXA
digital output
digital input
digital input
digital input
digital output
digital output
digital input
digital input
digital input
Receiver B outpot, non-invertedl
Transmit inhibit, channel B. If high BUSB,
Transmitter B digital data input, non-inverted
Transmitter B digital data input, inverted
Receiver A output, inverted
Receiver A output, non-inverted
Transmit inhibit, channel A. If high BUSA,
Transmitter A digital data input, non-inverted
Transmitter A digital data input, inverted
disabled
RXA
BUSB
low (HI-1567) or High (HI-1568)
disabled
RXB
BUSA
The HI-1567 family of data bus transceivers contain differ-
ential voltage source drivers and differential receivers.
They are intended for applications using a MIL-STD-1553
A/B data bus. The device produces a trapezoidal output
waveformduringtransmission.
Data input to the transmitter section of these devices is
from the complimentary CMOS /TTL inputs TXA/B and
. This produces a nominal 30V peak to peak signal
acrossa140ohm load.The transmitter isconnectedtothe
bus via a 1:2.5 transformer whose secondary is connected
totwo52ohm isolation resisterswhichfeedthe terminated
70ohmbus.Thiswillproduceanominalvoltageonthebus
of7.5voltspeaktopeak.
TRANSMITTER
TXA/B
The transmitter is automatically inhibited and placed in the
high impedance state when both TXA/B and
theratalogic“1”orlogic“0”simultaneously.Alogic“1:”ap-
plied to the TXINHA/B input will force the transmitter to the
highimpedancestate,regardlessofthestateofTXA/Band
TXA/B
are ei-
The receiver outputs can both be forced to a logic "0"
(HI-1567) or logic “1” (HI-1568) by setting RXENA or
RXENBlow.
TXA/B
RECEIVER
The receiver is transformer coupled to the bus by a 1:1
transformer. Its differential input stage drives a filter and
threshold comparator. CMOS/TTL data is outputted at the
RXA/Band
pins.
RXA/B
HOLT INTEGRATED CIRCUITS
2