The SGM3127 low-dropout bias supply for white LEDs
is a high-performance alternative to the simple ballast
resistors used in conventional white LED designs. It is
optimized for low power keypad and portable
backlighting applications.
The SGM3127 uses an internal resistor to set the bias
current for four LEDs, which are matched to ±5%. The
SGM3127's advantages over ballast resistors include
much lower bias variation with supply voltage variation,
significantly lower dropout voltage, and in some
applications, significantly improved efficiency.
The SGM3127 requires only a 50mV dropout voltage at
a 30mA load on each output to match the LED
brightness. SGM3127YN6G/TR资料下载