®
RT9468
5A Single Cell Li-Ion Switching Battery Charger with Direct
Charge, Power Path Management and USB OTG Boost Mode
General Description
The RT9468 is a switch-mode single cell Li-Ion/Li-Polymer
battery charger for portable applications. It integrates a
synchronous PWM controller, power MOSFETs, input
current sensing and regulation, high-accuracy voltage
regulation, and charge termination. The charge current is
regulated through integrated sensing resistors. The
RT9468 also features USB On-The-Go (OTG) support.
The
RT9468 integrates an easy-to-use direct charge function,
simply driving an external MOSFET to enable a direct
charge path, as well as over-voltage protection, over-current
protection, and watchdog functions.
The RT9468 optimizes for charging task by using a control
algorithm to vary the charge rate for different modes,
including pre-charge mode, fast charge mode (constant
voltage and constant current). The key charge parameters
are programmable through an I
2
C interface. The RT9468
will resume the charge cycle whenever the battery voltage
falls below an internal recharge threshold, and can
automatically enter sleep mode if the input power supply
is removed.
Other features include under-voltage protection, over-
voltage protection, thermal regulation and reverse leakage
protection.
The RT9468 is available in a WQFN-32L 4x4 package.
Features
Direct Charge with Over-Voltage Protection, Over-
Current Protection and Watchdog
High Efficiency 5A, 1.5MHz Switching Charger with
Output Inductor DFE252012F, TOKO
½
Charging Efficiency 90.25% at ICHG = 2A
Charging Efficiency 88.86% at ICHG = 3A
½
Charging Efficiency 84.2% at ICHG = 5A
Synchronous 1.5MHz/0.75MHz Fixed-Frequency
PWM Controller with Up to 95% Duty Cycle
Power Path Management by BATFET Control
Support High Voltage Input (9V/12V)
Support High Voltage Input Adapter (Pump Express
½
Applications
Cellular Telephones
Personal Information Appliances
Tablet PC, Power Bank
Portable Instruments
1.0/2.0/3.0)
Support IR Compensation Function from Charger
Output to Cell Terminal
Optimize Input Sourcing Capability to Prevent
Overload
2
½
AICR Current Limit Setting via I C
½
ILIM Pin for Current Limit Setting
½
Average Input Current Limit Measurement
Shipping Mode for Battery Leakage Reduction
½
Wake Up System, Exit Shipping Mode, and Reset
System by QON Pin
Automatic Charging
Average Input Current Regulation (AICR) :
0.1A to 3.25A in 50mA Steps
Charge Current Regulation Accuracy :
±
7%
Charge Voltage Regulation Accuracy :
±
1% (0 to
85°C)
°
Protection for Overall System Considerations
½
Thermal Regulation for Current Reduction and
Over-Temperature Protection
½
Input Over-Voltage Protection
½
Input Bad Adapter Protection
½
Battery Over-Voltage Protection
Support ADC Conversion for
½
VBUS, VBAT, VSYS, REGN, TS_BAT, IBUS, IBAT,
TEMP_JC, TS_BUS,VBATS, IBATS
INT Output for Communication with Host Through
I
2
C (Watch Dog / Polling Function)
is a registered trademark of Richtek Technology Corporation.
Copyright
©
2017 Richtek Technology Corporation. All rights reserved.
DS9468-01
November 2017
www.richtek.com
1
RT9468
Ordering Information
RT9468
Package Type
QW : WQFN-32L 4x4 (W-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Note :
Richtek products are :
½
Pin Configuration
(TOP VIEW)
PMID
PMID
PMID
VG
REGN
BTST
LX
LX
32 31 30 29 28 27 26 25
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.
VBUS
VBUS
VBUS
D+
D-
TS_BUS
SCL
SDA
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
24
23
22
PGND
33
21
20
19
18
17
PGND
PGND
SYS
SYS
BAT
BAT
BAT_SP
BAT_SN
Marking Information
5F= : Product Code
5F=YM
DNN
YMDNN : Date Code
Typical Application Circuit
RT9468
Normal Charge : 3.9V to 14V
Direct Charge : 3.0V to 7V
2.2µF
28
4.7µF
BAT_SP 18
698
12 ILIM
9
14
7
To I C BUS
2
VG
1, 2, 3
VBUS
PMID
29
30, 31, 32
4.7µF
4.7µF
REGN
BAT
19, 20
10µF
REGN
INT
QON
SCL
SDA
CEB
OTG
D+
D-
TS_BUS
TS_BAT 13
NTC
17
16
10m
8
11
10
BAT_SN
IBAT_SP
REGN
4
5
6
IBAT_SN
BTST
LX
PGND
23, 24
SYS
15
27
47nF
25, 26
21, 22
1µH
To System
10µF x 2
TA_NTC
Below are recommended components information
Pin
VBUS
PMID
BTST
SYS
REGN
Description
2.2F/25V/X5R
4.7F/25V/X5R
47nF/16V/X5R
10F/6.3V/X5R
4.7F/6.3V/X5R
Part Number
GRM155R61E225KE11
GRM188R61E475KE11
GRM033R61C473KE84
GRM185R60J106ME15
GRM155R60J475ME47
INT
OTG
CEB
ILIM
TS_BAT
QON
IBAT_SN
IBAT_SP
½
WQFN-32L 4x4
Battery
Pack
Package
0402
0603
0201
0603
0402
Manufacturer
muRata
muRata
muRata
muRata
muRata
Copyright
©
2017 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
2
DS9468-01
November 2017
RT9468
Pin
BAT
LX
VG
ILIM
Description
10F/6.3V/X5R
1H/20%
NMOS
698/1%
Part Number
GRM185R60J106ME15
DFE252012F-1R0
DMT2004UFDF_R0
RR0306S-6980-FNH
Package
0603
2.5 x 2.0mm
2.0 x 2.0mm
0201
Manufacturer
muRata
TOKO
DIODES
CYNTEC
Functional Pin Description
Pin No.
1, 2, 3
4
5
6
7
8
9
10
11
12
Pin Name
VBUS
D+
D-
TS_BUS
SCL
SDA
INT
OTG
CEB
ILIM
Power input.
USB D+ Port Connected to USB Receptacle.
USB D- Port Connected to USB Receptacle.
BUS temperature-sense input, connected to a resistor divider for temperature
programming. If there is no need for the battery temperature-sense function, a
50k resistor is connected to REGN and another 50k resistor to ground.
I
2
C interface serial clock input. Open-drain. An external pull-up resistor is required.
I
2
C interface serial data input/output. Open-drain. An external pull-up resistor is
required.
Interrupt output, active-low open-drain. Indicator of the charger/boost event for
system processor.
OTG boost mode enable control, active-high. Act with OTG_PIN_EN (0x01[1]).
Charger enable input, active-low.
Input current limit setting pin. A resistor is connected from ILIM pin to ground to set
the maximum input current limit. The actual input current limit is the lower value set
through the ILIM pin and IAICR register bits.
Battery temperature-sense input, connected to a resistor divider for temperature
programming. If there is no need for the battery temperature-sense function, a
50k resistor is connected to REGN and another 50k resistor to ground.
Internal BATFET enable control input. In shipping mode,
QON
is pulled Low for the
duration of t
SHIPMODE
(typical 0.9s) to exit shipping mode.
Negative battery current sense.
Positive battery current sense.
Negative battery voltage sense.
Positive battery voltage sense.
Battery connection node. Charging current output node. Internal BATFET is
connected between SYS and BAT.
System connection node. The internal BATFET is connected between SYS and
BAT. Connect a 20F ceramic capacitor between SYS and ground.
Power ground connection.
Switch node for output inductor connection.
Bootstrap capacitor connection for high-side gate driver. Connect a capacitor from
BTST to LX to power the internal gate driver.
Pin Description
13
14
15
16
17
18
19, 20
21, 22
23, 24
25, 26
27
TS_BAT
QON
IBAT_SN
IBAT_SP
BAT_SN
BAT_SP
BAT
SYS
PGND
LX
BTST
Copyright
©
2017 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS9468-01
November 2017
www.richtek.com
3
RT9468
Pin No.
Pin Name
Pin Description
Regulated output voltage to supply for the PWM low-side gate driver and the
bootstrap capacitor. Connect a 4.7F ceramic capacitor from REGN to GND.
1.If VBUS is plugged in, REGN will be powered by VBUS and regulated to 4.9V.
2.If VBUS is unplugged, the charger will operate in sleep mode and the REGN
voltage will be 0V.
* For #2. : Since the REGN voltage is also used to power the TS resistor, when the
charger is in sleep mode, the REGN will be woken up (be reactivated) if VBAT is
greater than forward voltage (V
F
) of the internal high-side (HS) MOS diode by
V
SLEEP_EXIT
with all function of the internal ADC being activated and I
2
C R/W. The
REGN wake-up time is 500ms.
Gate driver output for external N-MOSFET.
Connection point between the reverse blocking MOSFET and the high-side
switching MOSFET.
Power ground. The exposed pad must be connected to GND and well soldered to
a large PCB copper area for maximum power dissipation.
28
REGN
29
30, 31, 32
VG
PMID
33
PGND
(Exposed Pad)
Functional Block Diagram
VG
REGN
VBUS
Charge Pump
LDO
PMID
BTST
D+
D-
USB Host/
Adapter/Quick
Charge Detection
UUG Controller
Charger/OTG Controller
H/L
Driver
LX
Analog Base
VBUS
VSYS
VBAT/VBATS
IBUS
IBAT/IBATS
Protection
ADC
SCL
SDA
State Machine
REGN
Temp_JC
Sensing Amplifier
Power path
Controller
PGND
SYS
BAT
IBAT_SP
IBAT_SN
BAT_SP
BAT_SN
TS_BAT
TS_BUS
I C
2
INT
Silicon Temp
Detection
OTG
CEB
ILIM
QON
Copyright
©
2017 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
4
DS9468-01
November 2017
RT9468
Operation
The RT9468 is an integrated single cell Li-ion battery
switching charger with power path controller.
Base Circuits
Base circuits provide the internal power, VREGN and
reference voltage and bias current.
Protection Circuits
The protection circuits include the VINOVP, VINUVLO,
BATOVP and OTP circuits. The protection circuits turn
off the charging when the input power or die temperature
is in abnormal level.
Buck Regulator for Charging and Boost Regulator
as OTG
The multi-loop controller controls the operation of charging
process and current supply to the system. It also controls
the circuits as a Boost converter for OTG applications.
Battery Detection
The RT9468 is capable of doing the battery absence
detection. The detection protects the charger when battery
is removed accidentally.
Adapter Detection
If the poor input power source is connected to the RT9468,
the operation will be shut down by the adapter detection.
Power Path Management and Control
Once the battery voltage increases to a defined system
minimum regulation voltage, the internal path between
SYS and BAT will be fully turned on. That is, a better
charging efficiency can be achieved. When end of charge
occurs, the charging will stop and the internal path will be
turned off.
USB Charger Detection
The RT9468 can detect and distinguish Standard
Downstream Port, Charging Downstream Port and
Dedicated Charging Port via DP and DM pins.
TS Detection
The RT9468 detects the temperature of the battery pack
via REGN and TS pins. The REGN pin provides a constant
voltage source to drive the voltage divider composed of a
pulled-high resister and a NTC resister. The RT9468 reports
the sensing results via IRQ and status bits for COLD,
COOL, WARM and HOT.
I
2
C Controller
The key parameters of charging and OTG are programmable
through I
2
C commands.
Copyright
©
2017 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS9468-01
November 2017
www.richtek.com
5
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