概觀
The IS31BL3230 provides eight regulated current
sources, each delivers up to 90mA of load current with
careful selection of external sense resistors, all outputs
at the IS31BL3230 may be connected in parallel to
enable the current through the LED to be as high as
720mA.
The IS31BL3230 does not include a charge pump and
therefore has no noise and significantly improved the
efficiency. The external resistor, RSET1, determines the
constant current output of ports LED1 thru LED4, while
resistor RSET2 determines the constant current output of
ports LED5 thru LED8.
Brightness can be controlled with PWM techniques. The
constant current source is set with two external sense
resistors.
Alternatively, a PWM signal applied to the PWM pin can
vary the perceived brightness of the LED. The device is
in shut down mode when the PWM Input is logic low.