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R1285L Series

2ch DCDC for OLED

Outline

The R1285L 2ch DC/DC converter is designed for OLED Display power source. It contains a step up DC/DC converter and an inverting DC/DC converter to generate two required voltages by OLED Display.

Step up DC/DC converter generates boosted output voltage to 4.6V ~ 5.0V. Inverting DC/DC converter generates negative voltage -2.0V ~ -6.0V independently. Each of the R1285 series consists of an oscillator, a PWM control circuit, a voltage reference, error amplifiers, over current protection circuits, short protection circuits, an under voltage lockout circuit (UVLO), a complete shutdown switch and an Nch driver for boost operation, a Pch driver for inverting, and so on. A high efficiency boost and inverting DC/DC converter can be composed with external inductors, diodes, capacitors and resistors. Start up sequence is internally made.

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Features

Operating Voltage

2.3V ~ 4.8V

Step Up DC/DC (CH1)

Internal Pch MOSFET for complete shutdown (Ron=300mΩTyp.)
Internal Nch MOSFET Driver (Ron=300mΩTyp.)
Output Voltage (VOUTP) :	4.6V ~ 5.0V (0.2VStep)
Auto Discharge function for positive output
Internal Soft start function (Typ. 4.5ms)
Over Current Protection
Maximum Duty Cycle :	85%(Typ.)

Inverting DC/DC (CH2)

Internal Pch MOSFET Driver (Ron=600mΩ Typ.)
Output Voltage (VOUTN) :	-2V ~ -6V (0.1VStep) [ R1285LxxxA ]
Adjustable Vout Up to -6V with external resistors [ R1285L00xB ]
Auto Discharge function for negative output
Internal Soft start function (Typ. 4.5ms)
Over Current Protection
Maximum Duty Cycle :	90%(Typ.)

Control

Short Protection with timer latch function (Typ. 50ms)
	Short condition for either or both two outputs makes all output drivers off and latches. If the maximum duty cycle continues for a certain time, these output drivers will be turned off. This function prevents irregular current from overheating the R1285.

CE with start up sequence function ( CH1→CH2 )
UVLO function.
Operating Frequency :	1400kHz

Small package

DFN12 ( 2.7mm x 3.0mm )

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Applications

	Fixed voltage power supply for portable equipment
	Fixed voltage power supply for OLED

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Documents Download

Data Sheet (PDF)	Flyer (PDF)	Package Info. (PDF)	Mark Info. (PDF)	Quality Assurance Data (PDF)
R1285L Series EA-208-100210 (652KB)	R1285L Series EK-208-091101	DFN2730- 12	R1285L	Reliability