®
RT5021
6 + 3 Channels DC/DC PMU with Li-ion Battery Charger
for CMOS DSC/DV
General Description
The RT5021 is a complete power supply solution for digital
still cameras and other hand held devices. The RT5021 is
composed of a multi-channel DC/DC power converter unit,
a single-cell linear Li-ion battery charger, a charger type
detector, and an I
2
C control interface.
The power converter unit includes one synchronous step-
up converter (CH1), one synchronous step-up/down
converter (CH2), three synchronous step-down converters
(CH3/4/5), two LDOs with input power as low as 1.5V
(CH6/8), one WLED driver in synchronous high-voltage
step-up mode or low-voltage current regulator mode (CH7),
and a keep-alive LDO (CH9) 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, and under voltage
protection. RT5021 has a WAKEUP impulse generation
circuitry to monitor VIN or BAT installation event. To fulfill
most of applications, RT5021 has six preset power on/off
sequences.
The battery charger includes Auto Power Path
Management (APPM). No external MOSFETs are required.
The charger can enter 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 via the I
2
C control
interface. The battery regulation voltage and current can
be adjusted by JEITA standard temperature control or other
schemes set via the I
2
C interface. 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, VIN. The charger includes USB charger detection
circuitry via D+ and D- pins of USB interface to detect
USB standard downstream ports (SDP), USB charging
downstream port (CDP), dedicated charger port (DCP),
or Apple/Sony charger ports. RT5021 uses some
indicators to show charger states : two open drain ports
CHG and CHG2, and an interrupt (INT) to immediately notify
the state change.
RT5021 has I
2
C interface to control rich functions of Power
Converter Unit and Charger Unit. The RT5021 is available
in the WQFN-40L 5x5 package.
Simplified Application Circuit
BAT
Adapter/USB
System Power
I C Control
SDA
GND
2
Charger for Battery
Step-Up for Motor
Step-Up/Down for I/O
Step-Down for Core
Step-Down for Memory
Step-Down
LDO
Step-Up for LED Backlight
LDO
LDO for RTC
VIN
SYS
SCL
RT5021
PVD1
VO2
LX3
LX4
LX5
VO6
PVD7
VO8
VRTC
Copyright
©
2013 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS5021-01 April 2013
www.richtek.com
1
RT5021
Features
Power Converter Unit
CH1 LV Sync Step-Up
Support Up to 1A Loading, DVS (Dynamic Voltage
Scaling), Load-Disconnect, Up to 95% Efficiency,
PSM/PWM Selectable
CH2 LV Sync Step-Up/Down
Support Up to 1A Loading, DVS, Up to 95%
Efficiency, PSM/PWM Selectable
CH3/4 LV Sync Step-Down
Support Up to 1.3A Loading, DVS, Up to 95%
Efficiency, 100% (MAX) Duty Cycle, PSM/PWM
Selectable
CH5 LV Sync Step-Down
Support Up to 0.6A Loading, Up to 95% Efficiency,
100% (MAX) Duty Cycle
Output Voltage can be Selected from Preset List
or Set by External Feedback Network
CH6 Low Input Power LDO
V
IN
Range 1.5V to 5.5V
Output Voltage Level Selectable in I
2
C Register
CH7 WLED Driver in Either Sync Step-Up Operation
or Current Regulator Operation
Step-Up Mode with LED Open Protection (OVP7
16V or 25V, Selectable in I
2
C Register)
Step-Up Mode Support Series 2 to 6 WLED and
Load Disconnect Function
Current Regulator Mode for 1 WLED
31 WLED Dimming Levels
Automatic Mode Selection by External Circuit
Topology
CH8 Generic LDO
V
IN
Range 1.5V to 5.5V
Output Voltage Level Selectable in I
2
C Register
CH9 Low Quiescent LDO with Reverse Leakage
Prevention for RTC Power Supply
Fixed 3.05V Output
Six Preset Power On/Off Sequences by One Pin
SEQ
SEQ # 0 : CH2
→
CH3
→
CH4
SEQ # 1 : CH1
→
CH3
→
CH2
→
CH4
SEQ # 2 : CH1
→
CH3
→
CH4
→
CH2
SEQ # 3 : CH1
→
CH2
→
CH4
→
CH3
SEQ # 4 : CH1
→
CH4
→
CH3
→
CH2
SEQ # 5 : CH1
→
CH4
→
CH2
→
CH3
All Power Switches Integrated with Internal
Compensation
Discharge Output of Every Channels when Turning
Off
Wake Up Impulse to Monitor BAT and VIN Plug-In
Fixed 2MHz Switching Frequency for CH1/3/4/5,
Fixed 1MHz Switching Frequency for CH2/7
Charger Unit
28V Maximum Rating for V
IN
Power
Selectable Power Input Current Limit (0.1A / 0.5A /
1A / 1.5A)
Auto Power Path Management (APPM) with
Integrated Power MOSFETs
Battery Charging Current Control and Regulation
Voltage Control
Programmable Charging Current and Safe Charge
Timer
Optimized Charge Rate Via Thermal Feedback
Under Voltage Protection, Over Voltage Protection
Charger Status and VIN Power GOOD Indicators
Interrupt Indicator to JEITA Temperature/Fault/
Status Events when PMU is Enabled
Battery Temperature Events
Battery Removing Event
Charger in Thermal Regulation Control
Safety Timer Timeout
End of Charging
VIN Power Good
VIN < DPM Threshold 4.35V
Charger Type Detection Finishing
Charger Type Detection
Dedicated Charger : Support Apple and Sony
Charger
Secondary Charger Detection to Distinguish CDP
and DCP
I
2
C Control Interface : Support Fast Mode up to
400kb/s
Small 40-Lead WQFN Package
RoHS Compliant and Halogen Free
Copyright
©
2013 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
2
DS5021-01 April 2013
RT5021
Applications
DSC Power Supply System
CMOS-Sensor DV
Portable Instruments
Pin Configurations
(TOP VIEW)
VRTC
DN
DP
VIN
SYS
SYS
BAT
BAT
PVD3
LX3
40 39 38 37 36 35 34 33 32 31
Ordering Information
RT5021
Package Type
QW : WQFN-40L 5x5 (W-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Note :
Richtek products are :
RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
WAKE
PVD1
LX1
CHG2
FB7
PVD7
LX7
CHG
VO6
PVD6
1
2
3
4
5
6
7
8
9
10
11 12 13 14 15 16 17 18 19 20
41
30
29
28
27
26
25
24
23
22
21
GND
VP
TS
FB3
PVD2
LX2A
LX2B
VO2
FB2
VO8
SCL
Marking Information
RT5021GQW : Product Number
RT5021
GQW
YMDNN
YMDNN : Date Code
Copyright
©
2013 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS5021-01 April 2013
FB4
SEQ
LX4
EN
PVD45
LX5
INT
VO5/FB5
PVD8
SDA
WQFN-40L 5x5
www.richtek.com
3
RT5021
Functional Pin Description
Pin No.
1
Pin Name
WAKE
Pin Function
Wake-Up Impulse Push Pull Output. If VIN or BAT plug in, WAKE pin generates one
90ms-width high pulse to notify micro processor.
Power Output pin of CH1. To make CH1 stable, the power path from the pin PVD1 to its
output capacitors must be as short (≤1mm is better) and wide as possible to reduce its
parasitic inductance. The output capacitor must be ceramic capacitor (≥20μF).
Switch Node of CH1.
2nd Charger Status Indicator (Open Drain Output).
Feedback Input Pin of CH7 in Step-Up Mode or Current Regulator Mode
Power Output Pin of CH7 in Step-Up or Power Input Pin of CH7 in Current Regulator
Mode.
Switch Node of CH7 in Step-Up Mode.
LX7 initial voltage determine CH7 operation mode.
Charger Status Indicator (Open Drain Output).
Power Output Pin of CH6.
Power Input Pin of CH6.
Feedback Input Pin of CH4.
Power Sequence Selection for CH1 to CH4.
Switch Node of CH4.
Enable Pin of Power Converter Unit.
Power Input Pin of CH4 and CH5. To avoid the crosstalk between CH4 and CH5, the
power path from the pin PVD45 to its input capacitors must be as short (≤1mm is better)
and wide as possible to reduce its parasitic inductance. The input capacitance must be
≥10μF
with low ESR.
Switch Node of CH5.
Interrupt Indicator Open Drain Output. If events of NoBAT, THR, EOC, Battery
Temperature Change (TS_METER), PGOOD, SAFE, VIN DPM, or Charge Type
Detection Finishing (CHGRUN) happen, the output INT goes low and the INT bit in I
2
C
register bank 0x9 is set to be “1”. After INT bit is written to be “0”, INT goes high.
Output Voltage Sense Pin or feedback network input pin of CH5. The function is
2
selected by I C register.
Power Input Pin of CH8.
Data Signal Pin of I C Interface.
Clock Signal Pin of I C Interface.
Power Output Pin of CH8.
Feedback Input Pin of CH2.
Power Output Pin of CH2.
Switch Node B of CH2.
Switch Node A of CH2.
Power Input Pin of CH2.
2
2
2
3
4
5
6
7
8
9
10
11
12
13
14
PVD1
LX1
CHG2
FB7
PVD7
LX7
CHG
VO6
PVD6
FB4
SEQ
LX4
EN
15
16
PVD45
LX5
17
INT
18
19
20
21
22
23
24
25
26
27
VO5/FB5
PVD8
SDA
SCL
VO8
FB2
VO2
LX2B
LX2A
PVD2
Copyright
©
2013 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
4
DS5021-01 April 2013
RT5021
Pin No.
28
Pin Name
FB3
Feedback Input Pin of CH3.
Temperature Sense Input. The TS pin connects to a battery’s thermistor to
determine if the battery is too hot or too cold to charge. If the battery’s
temperature is out of range, charging is paused until it re-enters the valid range.
TS also detects whether the battery (with NTC) is present or not.
Power Output Pin of 3.3V Buffer for Battery Temperature Sensing.
Switch Node of CH3.
Power Input Pin of CH3.
Charger Output for Battery.
Power Output for System. Connect this pin to System with a minimum 10μF
ceramic capacitor to GND.
Supply Voltage Input.
USB D+ Input for Charger Type Detection.
USB D- Input for Charger Type Detection.
RTC LDO Power Output Pin.
Exposed PAD Should be Soldered to PCB and Connected to GND.
Pin Function
29
TS
30
31
32
33, 34
35, 36
37
38
39
40
41 (Exposed pad)
VP
LX3
PVD3
BAT
SYS
VIN
DP
DN
VRTC
GND
Copyright
©
2013 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS5021-01 April 2013
www.richtek.com
5
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