The SGM3122 is a charge pump with PWM brightness
control for white LED supplies in LCD display backlight
applications. The supply voltage ranges from 2.7V to
5.5V, it is ideally suited for all applications powered by a
single Li-ion battery cell or three to four NiCd, NiMH, or
alkaline battery cells.
The device provides a constant current for each LED,
and the initial current value can be set by an external
resistor. High efficiency is achieved by utilizing a 1×/1.5×
fractional conversion technique in combination with very
low dropout current sources.
The SGM3122 is capable of driving up to four channels of
LEDs at 30mA per channel from a 2.7V to 5.5V input.
Additionally, the current controlled charge pump ensures
low input current ripple and EMI. A low external part
count (two 0.47μF flying capacitors and two small 1μF
capacitors at VIN and VOUT) makes this part ideally
suited for small, battery-powered applications. SGM3122YTQ16G/TR资料下载
