TLC5949 Datasheet, PDF (37/51 Pages) Texas Instruments – 16-Channel, 12-Bit, ES-PWM, Full Self-Diagnosis LED Driver for 7-Bit Global BC LED Lamp

TLC5949
www.ti.com
SBVS219A – DECEMBER 2012 – REVISED DECEMBER 2012
When LOD and LSD data must be read with invisible brightness, the LATTMG bits should be set to the minimum
data larger than the calculated number of GSCLK periods defined by Equation 4. IDM does not work in power-
save mode. Figure 31 shows the LOD, LSD, OLD, and IDM circuit and Table 15 shows a truth table for LOD,
LSD, OLD, and IDM. Refer to Figure 32 for the PWM operation timing.
VCC
VLED
OLD
Control
2 mA (typ)
Current Flow
for OLD
LSD and
OLD Data
LOD Data
V_LSD
Current
Flow
for PWM
V_LOD
PWM
Control
IDM
Control
OUTn
Current
Flow
for IDM
GND
Figure 31. LOD, LSD, and OLD Circuit
SID DATA
0
1
Table 15. LOD, LSD, OLD, ISF, PTW, and TEF Truth Table
LOD
LED is not opened
(V_OUTn > V_LOD)
LED is open or
shorted to GND
(V_OUTn ≤ V_LOD)
CONDITION
LSD
OLD
ISF
LED is not shorted
(V_OUTn ≤ V_LSD)
OUTn does not leak to
GND
(V_OUTn > V_LSD when
constant-current
output off and OUTn
source current on)
IREF terminal is not
shorted
LED is shorted
between anode and
cathode, or shorted to
higher voltage side
(V_OUTn > V_LSD)
Current leaks from
OUTn to internal
GND, or OUTn is
shorted to external
GND with high
impedance
(V_OUTn ≤ V_LSD when
constant-current
output off and OUTn
source current on)
IREF terminal is
shorted to GND with
low impedance and
OUTn are forced off
PTW
TEF
Device temperature is
lower than pre-thermal
warning temperature
(temperature ≤ T_PTW)
Device temperature is
lower than thermal
shutdown threshold
temperature
(temperature ≤ T_TEF)
Device temperature is
higher than pre-
thermal warning
temperature
(temperature > T_PTW)
Device temperature is
higher than thermal
shutdown threshold
temperature and driver
is forced off
(temperature > T_TEF)
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