HI-1569
PIN DESCRIPTIONS
PIN
1, 40, 50, 55
2, 3
4, 5, 44, 52, 53, 60, 61
6, 7
8, 18, 23, 33
12, 20, 21, 28, 29, 36, 37
14
15
16
25
26
30
31
32
34, 35
38, 39
46
47
48
57
58
62
63
64
9 -11, 13, 17,19, 22, 24, 27
41 - 43, 45, 49, 51, 54, 56, 59
SYMBOL
GNDA
BUSA OUT
VDDA
BUSA OUT
GNDB
VDDB
RXB
RXENB
RXB
BUSB IN
BUSB IN
TXINHB
TXB
TXB
BUSB OUT
BUSB OUT
RXA
RXENA
RXA
BUSA IN
BUSA IN
TXINHA
TXA
TXA
N/C
FUNCTION
power supply
analog output
power supply
analog output
power supply
power supply
digital output
digital input
digital output
analog input
analog input
digital input
digital input
digital input
analog output
analog output
digital output
digital input
digital output
analog input
analog input
digital input
digital input
digital input
-
DESCRIPTION
Ground for channel A (Connect ALL pins)
MIL-STD-1533 bus driver A, positive signal
+5 volt power for channel A (Connect ALL pins)
MIL-STD-1533 bus driver A, negative signal
Ground for channel B (Connect ALL pins)
+5 volt power for channel B (Connect ALL pins)
Receiver B output, non-inverted
Receiver B enable. If low, forces RXB and RXB low
Receiver B output, inverted
MIL-STD-1553 bus receiver B, positive signal
MIL-STD-1553 bus receiver B, negative signal
Transmit inhibit, channel B. If high BUSB OUT, BUSB OUT disabled
Transmitter B digital data input, non-inverted
Transmitter B digital data input, inverted
MIL-STD-1533 bus driver B, positive signal
MIL-STD-1533 bus driver B, negative signal
Receiver A output, non-inverted
Receiver B enable. If low, forces RXB and RXB low
Receiver B output, inverted
MIL-STD-1553 bus receiver A, positive signal
MIL-STD-1553 bus receiver A, negative signal
Transmit inhibit, channel A. If high BUSA OUT, BUSA OUT disabled
Transmitter A digital data input, non-inverted
Transmitter A digital data input, inverted
Not connected. May be left open or connected to power or ground
FUNCTIONAL DESCRIPTION
The HI-1569 data bus transceiver contains differential volt-
age source drivers and differential receivers. It is intended
for applications using a MIL-STD-1553 A/B data bus. The
device produces a trapezoidal output waveform during
transmission.
TRANSMITTER
Data input to the device’s transmitter section is from the
complementary CMOS /TTL inputs TXA/B and TXA/B.
The transmitter accepts Manchester II bi-phase data and
converts it to differential voltages on BUSA/B OUT and
BUSA/B OUT. The transceiver outputs are either direct or
transformer coupled to the MIL-STD-1553 data bus. Both
coupling methods produce a nominal voltage on the bus of
7.5 volts peak to peak.
The transmitter is automatically inhibited and placed in the
high impedance state when both TXA/B and TXA/B are ei-
ther at a logic “1” or logic “0” simultaneously. A logic “1” ap-
plied to the TXINHA/B input will force the transmitter to the
high impedance state, regardless of the state of TXA/B and
TXA/B.
RECEIVER
The receiver accepts bi-phase differential data from the MIL-
STD-1553 bus through a direct or transformer coupled inter-
face. The receiver’s differential input stage drives a filter and
threshold comparator that produces CMOS/TTL data at the
RXA/B and RXA/B output pins.
Each set of receiver outputs can be independently forced to a
logic "0" by setting RXENA or RXENB low.
MIL-STD-1553 BUS INTERFACE
A direct coupled interface (see Figure 2) uses a 1:2.5 ratio
isolation transformer and two 55 ohm isolation resistors
between the transformer and the bus.
In a transformer coupled interface (see Figure 3), the
transceiver is connected to a 1:1.79 isolation transformer
which in turn is connected to a 1:1.4 coupling transformer. The
transformer coupled method also requires two coupling
resistors equal to 75% of the bus characteristic impedence
(Zo) between the coupling transformer and the bus.
HOLT INTEGRATED CIRCUITS
2
HOLTIC [ HOLT INTEGRATED CIRCUITS ]
