RT9971A数据手册集成电路（IC）的电源管理-专用规格书PDF

描述 Description

The RT9971A is a complete power supply solution for digital still cameras and other hand held devices. The RT9971A is a multi-channel power management IC including two step-up DC/DC converters, two step-down DC/DC converters, one selectable step-up/step-down DC/DC converter, one inverting DC/DC converter and one WLED driver.



The RT9971A is designed to fulfill the applications for DSC just as follows :



CH1 is a synchronous step-up output for motor or DSC system I/O power



CH2 is a selectable synchronous step-up/step-down output for motor or DSC system I/O power



CH3 and CH4 are synchronous step-down outputs for DSP core and memory power supply



CH5 is a high voltage step-up output for CCD bias power supply



CH6 is an inverting output for negative CCD bias power supply



CH7 is a high voltage step-up output for driving WLED



For the CH2, the step-up or step-down converter, operation mode can be selected by the SEL pin. Among all channels, there are 5 channels with the built-in internal compensation. The RT9971A also provides a transformerless inverting converter for supplying the CCD power. For the synchronous step-up and step down converters, the efficiency can be up to 95%. The IC provides load disconnection for channel 1 and channel 5. The IC has selectable RTC_LDO/SW1 that can be determined by the CN pin.



The RT9971A is able to support Li-ion and 2AA battery applications. The RT9971A provides WLED open protection, current limit, thermal shutdown protection, over voltage and under voltage protection to achieve complete protection. The RT9971A is available in WQFN-40L 5x5 package.

特性 Features

•One Synchronous Step-Up or Step-Down Selectable Convertor
•Support 2AA or Li-ion Battery Applications
•Preset On/Off Sequence
•5 Channels with Internal Compensation
•All Power Switches Integrated
•Up to 95%Efficiency
•100%(max) Duty Cycle for Step-Down Converter
•Adjustable Output Voltage
•LED PWM Dimming Control
•LED Open Protection
•Transformerless Inverting Converter for CCD
•Fixed 1MHz Switching Frequency at CH1 to CH7
•RTC_LDO/SW1 Selectable by CN Pin
•40-Lead WQFN Package
•RoHS Compliant and Halogen Free

应用 Application

• Digital Still Camera
• PDA
• Portable Device