RT5002
7 + 1 Channel DC/DC PMU with Li-Ion Battery Charger for
DSC
General Description
The RT5002 is a complete power supply solution for digital
still cameras and other handheld devices. It includes a
7+1 channel DC/DC power converter unit, a single-cell Li-
ion battery charger, and an I
2
C control interface.
The power converter unit includes one synchronous step-
up converter and three synchronous step-down converters
for DSP core, I/O, Motor, and memory power supply, one
synchronous high voltage step-up converter and one
asynchronous inverting converter for CCD± bias, one
WLED driver in either synchronous high voltage step-up
or current source operation, and one low quiescent LDO
for RTC application. All converters are internally frequency
compensated and integrate power MOSFETs. The power
converter unit provides complete protection functions: over
current, thermal shutdown, over voltage, over-load, and
under voltage protection.
The battery charger includes Auto Power Path
Management (APPM). No external MOSFETs are required.
The charger enters sleep mode when power is removed.
Charging tasks are optimized by using a control algorithm
to vary the charge rate, including pre-charge mode, fast
charge mode and constant voltage mode. The charge
current can also be programmed with an external resistor
and modified via the I
2
C control interface. The scope that
the battery regulation voltage can be modified via the I
2
C
interface depends on the battery temperature. The internal
thermal feedback circuitry regulates the die temperature
to optimize the charge rate for all ambient temperatures.
The charging task will always be terminated in constant
voltage mode when the charging current reduces to the
termination current of 10% x I
CHG_FAST
. The charger
includes under voltage and over-voltage protection for the
supply input voltage, V
IN
.
Features
Power Converter Unit :
One Channel LV Sync Step-Up and Three Channel
LV Sync Step-Down
Up to 95% Efficiency
One Sync Step-Up and One Async Inverting for
±
CCD± bias
One WLED Driver in either Sync Step-Up or Current
Source Operation
WLED Driver with Dimming Control
Step-Up Mode with LED Open Protection (OVP7)
One Low Quiescent LDO with Reverse Leakage
Prevention for RTC Power Supply
Preset On/Off Sequence of CH1, CH2, CH3, CH4
(1
→
3
→
4
→
2)
Two Preset On/Off Sequence of CH5, CH6 (5
→
6 or
6
→
5)
All Power Switches Integrated with Internal
Compensation
All Step-Up Converters with Load Disconnect
Wake Up Impulse to Monitor BAT and VIN Plug-In
Charger Unit :
28V Maximum Rating for VIN Power
Selectable Power Current Limit (0.1A / 0.5A / 1.5A)
Auto Power Path Management (APPM) and
Integrated Power MOSFETs
Battery Charging Current Control
Battery Regulation Voltage Control
Programmable Charging Current and Safe Charge
Timer
Under Voltage and Over Voltage Protection
Optimized Charge Rate via Thermal Feedback
Interrupt Indicator to Fault/Status Events
I
2
C Control Interface : Support Fast Mode up to
400kb/s
Voltage Divider for Sensing Battery Voltage Level
Small 40-Lead WQFN Package
RoHS Compliant and Halogen Free
Applications
DSC
DS5002-00
November 2011
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
