TLC5948A Datasheet, PDF (38/50 Pages) Texas Instruments – 16-Channel, 16-Bit, ES-PWM, Full Self-Diagnosis LED Driver

TLC5948A
SBVS192 – MARCH 2012
www.ti.com
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 34 shows the LOD, LSD, OLD, and IDM circuit and Table 18 shows a truth table for LOD,
LSD, OLD, and IDM. Refer to Figure 35 for the PWM operation timing.
VCC
VLED
OLD
Control
2 mA (typ)
Current Flow
for OLD
LSD/OLD Data
LOD Data
V_LSD
Current
Flow
for PWM
V_LOD
PWM
Control
IDM
Control
OUTn
Current
Flow
for IDM
GND
Figure 34. LOD, LSD, and OLD Circuit
SID
DATA
0
1
Table 18. 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
PTW
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
Device temperature
is lower than pre-
thermal warning
temperature
(temperature ≤
T_PTW)
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
Device temperature
is higher than pre-
thermal warning
temperature
(temperature >
T_PTW)
TEF
Device temperature
is lower than
thermal shutdown
threshold
temperature
(temperature ≤
T_TEF)
Device temperature
is higher than
thermal shutdown
threshold
temperature and
driver is forced off
(temperature >
T_TEF)
38
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