HI-1565PST 查看數據表（PDF） - Holt Integrated Circuits
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HI-1565PST Datasheet PDF : 10 Pages
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HI-1565, HI-1566
PIN DESCRIPTIONS
PIN
(DIP/ESOIC)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
SYMBOL
VDDA
BUSA
BUSA
RXENA
GNDA
VDDB
BUSB
BUSB
RXENB
GNDB
RXB
RXB
TXINHB
TXB
TXB
RXA
RXA
TXINHA
TXA
TXA
FUNCTION
power supply
analog output
analog output
digital input
power supply
power supply
analog output
analog output
digital input
power supply
digital output
digital output
digital input
digital input
digital input
digital output
digital output
digital input
digital input
digital input
DESCRIPTION
+5 volt power for bus 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 RXA low (HI-1565) or High (HI-1566)
Ground for bus A
+5 volt power for bus 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 RXB low (HI-1565) or High (HI-1566)
Ground for bus B
Receiver B output, inverted
Receiver B output, non-inverted
Transmit inhibit, bus B. If high BUSB, BUSB disabled
Transmitter B digital data input, non-inverted
Transmitter B digital data input, inverted
Receiver A output, inverted
Receiver A output, non-inverted
Transmit inhibit, bus A. If high BUSA, BUSA disabled
Transmitter A digital data input, non-inverted
Transmitter A digital data input, inverted
FUNCTIONAL DESCRIPTION
The HI-1565 family of data bus transceivers contain differen-
tial voltage source drivers and differential receivers. It is in-
tended 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 com-
plementary CMOS /TTL inputs TXA/B and TXA/B. The
transmitter accepts Manchester II bi-phase data and con-
verts it to differential voltages on BUSA/B and BUSA/B. The
transceiver outputs are either direct- or transformer-coupled
to the MIL-STD-1553 data bus. Both coupling methods pro-
duce a nominal voltage on the bus of 7.5 volts peak to peak.
produces CMOS/TTL data at the RXA/B and RXA/B output
pins. When the MIL-STD-1553 bus is idle and RXENA or
RXENB are high, RXA/B will be logic “0” on HI-1565 and
logic “1” on HI-1566.
The receiver outputs are forced to the bus idle state (logic “0”
for HI-1565 or logic “1” for HI-1566) when RXENA or RXENB
is 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. The primary center-
tap of the isolation transformer must be connected to GND.
The transmitter is automatically inhibited and placed in the
high impedance state when both TXA/B and TXA/B are
driven with the same logic state. A logic “1” applied to the
TXINHA/B input forces 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 the same direct- or transformer-
coupled interface as the transmitter. The receiver’s differen-
tial input stage drives a filter and threshold comparator that
In a transformer-coupled interface (see Figure 2), 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.
Figure 3 and Figure 4 show test circuits for measuring
electrical characteristics of both direct- and transformer-
coupled interfaces respectively. (See electrical
characteristics on the following pages.)
HOLT INTEGRATED CIRCUITS
2
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