YB1517

The YB1517 is a Current-mode PWM step-up DC-DC converter. It can drive up to 18V at 3.0V input and 30V at 5.0V input. The 1 MHz switching frequency allows it to work with tiny external components, therefore minimize the footprint and cost in space consideration products.

One of the major applications for YB1517 is in the dc to dc converter and OLED power supply and TFT panel power supply.

When using YB1517 for white LED driving, it is not recommended to control LED brightness by applying a PWM signal to the CTRL pin, because the built-in soft-start circuit might interfere the start-up operation of YB1517 and cause lower brightness. It operates as current source to drive up to 5 white LEDs in series at 3.0V input and up to 8 white LEDs at 5.0V input. Series connecting of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors. The light intensity of these LEDs is proportional to the current passing through them.

YB1517 has integrated Latched Over Voltage Protection that prevents damage to the device in case of a high impedance output due to faulty LED or open circuit caused by abnormal conditions.