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SM8132A Datasheet, PDF (14/18 Pages) Nippon Precision Circuits Inc – White LED Driver IC | |||
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SM8132A
For example, if the VIN voltage is low and the VOUT output voltage in Ã1.0 mode does not provide sufï¬cient
drive current, then the mode reset will cause a LED undercurrent condition. The LED undercurrent detector
circuit will output an LED undercurrent signal immediately after the switch to Ã1.0 mode, but the output will
stay in Ã1.0 mode and not return to Ã1.5 mode for the duration of the mode hold time. Consequently, the VOUT
output is not boosted during the 85µs (min) to 200µs (max) mode hold time and the voltage drops and the LED
brightness is reduced. However, the LEDs are OFF for a maximum of 200µs only, and this is not discernible to
the naked eye and thus is not a problem.
VIN input voltage
Mode reset
(1.4sec/cycle)
Mode hold
(H: hold)
VOUT mode
(H: 1.5, L: 1.0)
VOUT
output voltage
Low ILED detector
(H: low ILED)
1.4sec
max
200µS
1.0 1.5 threshold
4.2V
VOUT drop due to the mode reset single
NIPPON PRECISION CIRCUITS INC.â14
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