Ricoh R1286K Manuals

The R1286 series 2ch DC/DC power converter is designed for AMOLED display power source. It contains a step up DC/DC converter and an inverting DC/DC converter. Step up DC/DC converter generates boosted output voltage to 4.6V ~ 5.8V(Selectable). Inverting DC/DC converter generates negative voltage down to -2.0V ~ -6.0V(Selectable) that is dynamically adjustable with single wire interface signal. R1286 consist of a voltage reference, error amplifiers, an oscillator, PWM control circuits, over current protection circuits, short protection circuits, an under voltage lockout circuit (UVLO), thermal shutdown circuit, a NMOS driver and a synchronous PMOS switch for boost converter, a PMOS driver and a synchronous NMOS switch for inverting converter, and so on. High efficiency boost and inverting DC/DC converters can be composed with two external inductors and three capacitors.

The R1286K Series are CMOS-based PWM step-up/inverting DC/DC converters featuring 250mA×2 output current with synchronous rectifier. R1286K includes a soft start circuit, an under-voltage lockout circuit (UVLO), a latch protection circuit, a thermal shutdown circuit, and a shutdown circuit. By simply using two inductors and three capacitors as external components, a high-efficiency step-up/inverting DC/DC converter can be easily configured. R1286K is available in two types: R1286K001B is the type to which the output voltage (VOUTP and VOUTN) can be adjusted by external resistors. R1286KxxxA/C~M are the type to which the step-up output voltage (VOUTP) is internally fixed and the inverting output voltage (VOUTN) can be adjusted dynamically by the single wire interface. The R1286K has a sequenced start up. After the CE pin is enabled, the step-up output is starting up followed by the inverting output after a delay time. As for shutdown, both outputs will be turned off by the auto-discharge function. R1286K is used for applications such as LCD and AMOLED displays.