hi-8599 Holt Integrated Circuits, Inc., hi-8599 Datasheet - Page 6

• Manufacturer Part Number: hi-8599
• Description: Transmitter With Line Driver And Dual Receivers
• Manufacturer: Holt Integrated Circuits, Inc.

FUNCTIONAL DESCRIPTION (cont.)
TIMING DIAGRAMS
LINE DRIVER OPERATION
The line driver in the HI-8599 is designed to directly drive the
ARINC 429 bus.
TXB(OUT)) provide a differential voltage to produce a +10 volt
One, a -10 volt Zero, and a 0 volt Null. Setting Control Register bit
13 to zero causes a slope of 1.5 s on the ARINC outputs. A one
in Control Register bit 13 causes a slope of 10 s. Timing is set by
on-chip resistor and capacitor and tested to be within ARINC
requirements.
slope. T
output, and is for applications where additional external series
resistance is required, such as lightning protection.
REPEATER OPERATION
Repeater mode of operation allows a data word that has been
received by the HI-8599 to be placed directly into its FIFO for
transmission. Repeater operation is similar to normal receiver
operation. In normal operation, either byte of a received data
word may be read from the receiver latches first by use of SEL
input. During repeater operation however, the lower byte of the
data word must be read first. This is necessary because, as the
data is being read, it is also being loaded into the FIFO and the
transmitter FIFO is always loaded with the lower byte of the data
word first. Signal flow for repeater operation is shown in the
Timing Diagrams section.
TXB(OUT)
TXA(OUT)
he HI-8599 has 10 ohms in series with each line driver
No additional hardware is required to control the
DATA BUS
CWSTR
The two ARINC outputs (TXA(OUT) and
DATA
ARINC BIT
BIT 30
NULL
m
DATA
m
BIT 31
HOLT INTEGRATED CIRCUITS
DATA RATE - EXAMPLE PATTERN
NULL
LOADING CONTROL WORD
t
CWSTR
DATA
t
CWSET
HI-8599
BIT 32
VALID
6
NULL
HI-8599-10
The “-10” version of the HI-8599 product require a 10 Kohm
resistor to be placed in series with each ARINC input without
affecting the ARINC input thresholds. This option is especially
useful in applications where external lightning protection is
required.
Each ARINC input pin must be connected to the ARINC bus
through a 10 Kohm resistor in order for the chip to properly detect
the correct ARINC levels. The typical 10 volt differential signal is
translated and input to a window comparator and latch. The
comparator levels are set so that with the external 10 Kohm
resistors, they are just below the standard 6.5 volt minimum
ARINC data threshold and just above the 2.5 volt maximum
ARINC null threshold.
Please refer to the Holt AN-300 Application Note for additional
information and recommendations on lightning protection of Holt
line drivers and line receivers.
POWER SUPPLY SEQUENCING
The power supplies should be controlled to prevent large currents
during supply turn-on and turn-off. The recommended sequence is
V+ followed by Vcc, always ensuring that V+ is the most positive
supply. The V- supply is not critical and can be asserted at any
time.
t
CWHLD
WORD GAP
NEXT WORD
BIT 1