HI-8585 Holt Integrated Circuits, HI-8585 Datasheet - Page 2

• Manufacturer Part Number: HI-8585
• Description: (HI-8585 / HI-8586) ARINC 429 LIN DRIVER
• Manufacturer: Holt Integrated Circuits

FUNCTIONAL DESCRIPTION
Figure 1 is a block diagram of the line driver. The +5V and
-5V levels are generated internally using on-chip zeners.
Currents for slope control are set by zener voltages across
on-chip resistors.
The TX0IN and TX1IN inputs receive logic signals from a
control transmitter chip such as the HI-6010 or HI-8282.
TXAOUT and TXBOUT hold each side of the ARINC bus at
Ground until one of the inputs becomes a One. If for exam-
ple TX1IN goes high, a charging path is enabled to 5V on an
“A” side internal capacitor while the “B” side is enabled to
-5V. The charging current is selected by the SLP1.5 pin. If
the SLP1.5 pin is high, the capacitor is nominally charged
from 10% to 90% in 1.5µs. If SLP1.5 is low, the rise and fall
times are 10µs.
APPLICATION INFORMATION
Figure 2 shows a possible application
of the HI-8585/86 interfacing an ARINC
transmit channel from the HI-6010.
TRANSLATION
PROTECTION
VOLTAGE
ESD
AND
FIGURE 1 - LINE DRIVER BLOCK DIAGRAM
CONTROL
CONTROL
LOGIC
LOGIC
NULL
ZERO
NULL
ZERO
ONE
ONE
HOLT INTEGRATED CIRCUITS
HI-8585, HI-8586
SLP1.5
-5V
-5V
5V
5V
CURRENT
CONTROL
CURRENT
CONTROL
2
“B” SIDE
“A” SIDE
A unity gain buffer receives the internally generated slopes
and differentially drives the ARINC line. Current is limited
by the series output resistors at each pin. There are no
fuses at the outputs of the HI-8585 as exists on the HI-8382.
The HI-8585 has 37.5 ohms in series with each output. The
HI-8586 has 10 ohms in series. The HI-8586 is for applica-
tions where more series resistance is added externally,
typically for lightning protection devices.
FIGURE 2 - APPLICATION DIAGRAM
2
8
4
3
6
7
5
4
1
HI-8585 = 37.5 OHMS
HI-8586 = 10.0 OHMS
HI-8585 = 37.5 OHMS
HI-8556 = 10.0 OHMS
1
5
8
6
7
2
3
TXAOUT
TXBOUT