Triple DC/DC Boost Converter for AMOLED
• Boost Converter to Supply Positive AVDD Voltage from 5.8V to 7.9V
• Boost Converter to Supply AMOLED Positive Voltage 4.6V
• Inverter Converter to Supply AMOLED Negative Voltage from 0.8V to 4.8V
• Maximum Output Current up to 300mA for AMOLED Positive & Negative Power Supply
• Maximum Output Current up to 50mA for AVDD Output Voltage
• Typical Peak Efficiency : 90% (40mA to 150mA)
• PWM Mode @ 1.5MHz Switching Frequency
• High Output Voltage Accuracy
• Excellent Line and Load Transient
• Excellent Line and Load Regulation
• Programmable Negative and AVDD Voltage by SWIRE Pin
• Fast Outputs Discharge Function
• Low Quiescent Current


• Cellular Phones
• Digital Cameras
• PDAs and Smart Phones
• Probable Instrument


RT4721 is a triple channels DC/DC converter which is designed to provide the power of AMOLED. It integrates step up DC/DC and an inverting converter to provide the positive and negative output voltage required by AMOLED. For the portable application, board space and efficiency are always major concerns. The high switching frequency of RT4721 allows the use of low inductance inductor to save the board space. For the negative and AVDD output voltage, both can be programmed by external MCU through single wire (SWIRE pin). The output voltage range of negative output voltage is 0.8V to 4.8V and AVDD voltage is 5.8V to 7.9V. RT4721 has OTP, SCP, UVLO and over current protections. The RT4721 is available in a WQFN-16L 3x3 package to achieve saving PCB space.