RT9986A Datasheet, PDF (1/24 Pages) Richtek Technology Corporation – 7-CH DC/DC Converter for DSC

RT9986A
7-CH DC/DC Converter for DSC
General Description
The RT9986A is a complete power supply solution for
digital still cameras and other handheld devices. It includes
one synchronous step-up DC/DC converter with load
disconnect, one selectable synchronous step-up/step-
down DC/DC converter, two synchronous step-down DC/
DC converters, one synchronous high voltage step-up DC/
DC converter, one inverting DC/DC converter, and one
selectable synchronous high voltage step-up/current-
source for WLED. In addition, the RT9986A also includes
one RTC_LDO, one voltage detector, and one System
Reset. All power MOSFETs are integrated in the RT9986A.
The RT9986A is designed to fulfill the applications for DSC
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 synchronous high voltage step-up output for CCD
bias power supply
CH6 is an inverting output for negative CCD bias power
supply
CH7 is a selectable synchronous high voltage step-up/
current source for driving WLED
The selectable step-up/step-down converter can be auto
selected by external component topology. For the
RT9986A, all 7-CHs have built in internal compensation.
The RT9986A also provides a transformerless inverting
converter for supplying CCD power. For the low voltage
synchronous step-up and step down converters, efficiency
can be up to 95%.
The RT9986A provides comprehensive protection features
including over current protection, thermal shutdown
protection, over voltage protection, overload protection,
and under voltage protection.
Features
z CH2 Step-Up/Step-Down Auto-Selected by External
Topology
z Preset On/Off Sequence of CH1, CH2, CH3, CH4
(1 → 3 → 4 → 2)
z Preset On/Off Sequence of CH5, CH6 (5 → 6)
z All Channels with Internal Compensation
z All Power Switches Integrated
z All Step-Up Converter with Load Disconnect
z Step-Down DC/DC Converter
` Up to 95% Efficiency
` 100% (max) Duty Cycle
z Low Voltage Step-Up DC/DC Converter
` Adjustable Output Voltage
` Up to 95% Efficiency
z WLED Driver
` Auto-Selected by External Topology
` Current Source Mode with 30mA DC Current
` Step-Up Mode with LED Open Protection (OVP7)
` Direct PWM Dimming Control
z Fixed 2MHz Switching Frequency for CH1/2/3/4,
Fixed 1MHz Switching Frequency for CH5/6/7
z Small 32-Lead WQFN Package
z RoHS Compliant and Halogen Free
Applications
z Digital Still Camera
z PDA
z Portable Devices
Marking Information
EZ= : Product Code
EZ=YM
DNN
YMDNN : Date Code
DS9986A-00 May 2011
www.richtek.com
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