A8508 View Datasheet(PDF) - Allegro MicroSystems
Part Name
Description
MFG CO.
A8508
Allegro MicroSystems
'A8508' PDF : 28 Pages View PDF
A8508
Wide Input Voltage Range, High Efficiency
8-Channel Fault Tolerant LED Driver
OVP limit is reached,
and string is removed
from control loop
VOUT (30 V)
VLEDx
LED string opens
C2
IOUT
Control loop reduces VOUT
to new regulation level
System VOUT clamped to
OVP setting of master IC
VOUT
LED string opens
VLEDx
C2
OVP of slave is never
exceeded, so VOUT remains
higher than necessary
C1
IOUT
C3
C3
t
Figure 32. Proper OVP setting for the master and slave configuration. The
master OVP is set higher than the slave, shows VOUT (ch1, 2 V/div.), pin
voltage VLEDx (ch2, 2 V/div.), and IOUT (ch3, 200 mA/div.), t = 2 ms/div.
t
Figure 33. OVP on the master IC is set too low and the IC does not
respond properly to the open LED condition on the slave IC; shows VOUT
(ch1, 10 V/div.), VLEDx (ch2, 2 V/div.), and IOUT (ch3, 200 mA/div.),
t = 100 ms/div.
Allegro MicroSystems, Inc.
20
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Share Link: 