TLC5930 Datasheet, PDF (26/39 Pages) Texas Instruments – 12-CHANNEL LED DRIVER

TLC5930
SLLS528 – MARCH 2002
PRINCIPLES OF OPERATION
OUT0
+
INTERNAL OUT0
LIGHT ON SIGNAL
INTERNAL OUT1
LIGHT ON SIGNAL
+
OUT1
.
.
.
OUT10
.
.
.
.
.
.
+
INTERNAL OUT10
LIGHT ON SIGNAL
INTERNAL OUT11
LIGHT ON SIGNAL
+
OUT11
OVMFA
OVMF[0]
OVMF[1]
.
.
.
.
.
.
OVMF[10]
OVMF[11]
+
COMPARISON
VOLTAGE
UDG–02039
Figure 9. OVM Function
The comparator works so that if a flag is set when read in its operation, voltage across the constant-current
output terminals is lower than the comparison voltage. However, the constant-current output is needed to be
turned on approximately 1 µs continuously until the comparator starts working. For this reason, the following
sequence is recommended to ensure the proper result.
Table 11. OVM Function Sequence Example
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ _{1 Gray-scale data, dot correction data setting packet}
Set the desired value for output current.
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ 2 Operation mode setting packet: force ON = 1 and force
OFF = 0
Set OVM detection voltage and demand all output force ON.
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ _{3 HSYNC synchronization packet}
Al outputs force ON.
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ _{4 Waitatleast1µs}
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ 5 OVM information reading packet or failure monitor information Read OVM comparison result.
reading packet
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ _{6 Operation mode setting packet; force ON = 0 and force}
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ _{OFF = 0}
Demand return to normal operation.
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ 7 HSYNCsynchronizationpacket
Return to normal operation
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