SM8131B View Datasheet(PDF) - Nippon Precision Circuits
Part Name
Description
MFG CO.
'SM8131B' PDF : 21 Pages View PDF
SM8131B
For example, if the VIN voltage is low and the VOUT output voltage in ×1.0 mode does not provide sufficient
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 ×1.0 mode, but the output will
stay in ×1.0 mode and not return to ×1.5 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.—13
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