hi-1569pqt Holt Integrated Circuits, Inc., hi-1569pqt Datasheet - Page 2

• Manufacturer Part Number: hi-1569pqt
• Description: 5v Monolithic Dual Transceiver
• Manufacturer: Holt Integrated Circuits, Inc.

PIN DESCRIPTIONS
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
The transmitter accepts Manchester II bi-phase data and
converts it to differential voltages on
BUSA B OUT.
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
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.
41 - 43, 45, 49, 51, 54, 56, 59
9 -11, 13, 17,19, 22, 24, 27
12, 20, 21, 28, 29, 36, 37
4, 5, 44, 52, 53, 60, 61
/
/
1, 40, 50, 55
8, 18, 23, 33
34, 35
38, 39
2, 3
6, 7
PIN
14
15
16
25
26
30
31
32
46
47
48
57
58
62
63
64
The transceiver outputs are either direct or
BUSA OUT
BUSA
BUSB OUT
BUSB
SYMBOL
BUSB IN
BUSB
BUSA
BUSA IN
TXINHB
TXINHA
RXENB
RXENA
GNDA
GNDB
VDDA
VDDB
RXB
RXB
RXA
RXA
TXB
TXB
TXA
TXA
N/C
OUT
OUT
IN
IN
BUSA/B OUT and
HOLT INTEGRATED CIRCUITS
TXA B
analog output
analog output
analog output
analog output
power supply
power supply
power supply
power supply
FUNCTION
digital output
digital output
digital output
digital output
analog input
analog input
analog input
analog input
digital input
digital input
digital input
digital input
digital input
digital input
digital input
digital input
/ are ei-
-
TXA B
/ .
HI-1569
2
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
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,
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
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,
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
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
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.
RXA B
/ output pins.
DESCRIPTION
RXB
RXB
BUSA
BUSB
low
low
OUT disabled
OUT disabled