RT9505
Linear Single Cell Li-Ion Battery Charger IC
General Description
The RT9505 is a fully integrated low cost single-cell Li-
Ion battery charger IC ideal for portable applications. The
RT9505 is capable of being powered up from AC adapter.
The RT9505 enters sleep mode when AC adapter is
removed.
The RT9505 optimizes the charging task by using a control
algorithm including preconditioning mode, fast charge
mode and constant voltage mode. The charging task is
terminated as the charge current drops below the preset
threshold. The AC adapter charge current can be
programmed up to 1A with an external resister. The internal
thermal feedback circuitry regulates the die temperature
to optimize the charge rate for all ambient temperatures.
The RT9505 features 18V maximum rating voltages for
AC adapter. The other features are under voltage
protection, over voltage protection for AC adapter supply
and battery temperature monitoring.
Features
18V Maximum Rating for AC Adapter
Internal Integrate P-MOSFETs
AC Adapter Power Good Status Indicator
Charge Status Indicator
Under Voltage Protection
Over Voltage Protection
Automatic Recharge Feature
Battery Temperature Monitoring
Small 10-Lead WDFN Package
Thermal Feedback Optimizing Charge Rate
RoHS Compliant and 100% Lead (Pb)-Free
Applications
Digital Cameras
Cellular Phones
Personal Data Assistants (PDAs)
MP3 Players
Hand Held PCs
Ordering Information
RT9505
Package Type
QW : WDFN-10L 3x3 (W-Type)
Lead Plating System
P : Pb Free
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.
Pin Configurations
(TOP VIEW)
ACIN
1
NC
2
CHG_S
3
PGOOD
4
GND
5
GND
11
10
9
BATT
TS
8
EN
7
NC
ISETA
9
WDFN-10L 3x3
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
DS9505-02 April 2011
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1
RT9505
Typical Application Circuit
Battery Pack
RT9505
AC
Adapter
1
1uF
3
CHG_S
4 PGOOD
GND
TS
EN
ISETA
9
8
6
R
SET
Chip Shutdown
Chip Enable
0.1uF to 10uF
ACIN
BATT
10
+
To System
To System
5, Exposed Pad (11)
Pre-Charge Phase
Fast Charge
Phase
Constant Voltage
Phase &
Re-Charge Phase
Standby Phase
Programmed
Charge Current
Battery
Voltage
Charging
Current
4.1V Recharge
Threshold
1/10 Programmed
Charge Current
2.8V Precharge
Threshold
Charge
Complete
Functional Pin Description
Pin No.
1
2, 7
3
4
5
6
8
9
10
Pin Name
ACIN
NC
CHG_S
PGOOD
GND
ISETA
EN
TS
BATT
Pin Function
Wall Adaptor Charge Input Supply.
No Internal Connection.
Charge Status Indicator Output (open drain).
Power Good Indicator Output (open drain).
Ground.
Wall Adaptor Supply Charge Current Set Point.
Charge Enable Input (active low).
Temperature Sense Input.
Battery Charge Current Output.
Exposed pad should be soldered to PCB board and connected to GND.
11 (Exposed Pad) GND
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2
DS9505-02 April 2011
RT9505
Function Block Diagram
ACIN
OVP
Comparator
2.5V
GND
Charge Input Control
+
-
OVP
SENSE
FET
ACIN
PFET
ISETA
2.5V
V
REF
Thermal
Sense
115 C
2.5V
Recharge
Comparator
+
2.5V
-
-
+
BATT
0.5V
0.25V
+
-
V/I
Precharge
Comparator
+
2.5V
-
Precharge
V/I
Recharge
Current
Amplifier
0.25V
2.5V
Precharge
Voltage
Amplifier
Charge Done
Charge
Disable
Temperature Fault
CHG_S
Logic
VCC
Tcrmination
Comparator
-
0.25V
0.9V
+
-
+
+
-
PGOOD
1uA
Temperature
Sense
EN
TS
DS9505-02 April 2011
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3
RT9505
Table
RT9505 Flow Chart
Start-Up
Precharge Phase
Fast Charge Phase
Standby/Fault
Recharge Phase
ACIN
Power Up
DISABLE
V
EN
> 1.4V ?
YES
DISABLE MODE
P-MOSFET OFF
I
BATT
= 0
NO
V
ACIN
> 6.5V or
UVP / OVP
V
ACIN
< 4.4V?
YES
OVP/UVP MODE
P-MOSFET OFF
I
BATT
= 0
NO
V
ACIN
< V
BATT
?
SLEEP
YES
SLEEP MODE
P-MOSFET OFF
I
BATT
= 0
NO
Start-Up
1ms Delay
V
TS
> 2.5V
or
V
TS
< 0.5V?
YES
NO
TEMP
FAULT/CHG_S
HIGH
IMPEDANCE
RECHARGE
V
BATT
> 2.8V?
I
BATT
= 0.1 Charge
Current
/CHG_S Pull Down
YES
NO
YES
I
BATT
= Charge
Current
/CHG_S Pull Down
YES
NO
STANDBY
PFET OFF
V
BATT
= 4.2V,
I
BATT
= 0
YES
V
BATT
> 4.1 V?
NO
V
BATT ~
4.2V,
I
BATT
< 0.1 I
CHG
?
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DS9505-02 April 2011
RT9505
Absolute Maximum Ratings
(Note 1)
−0.3V
to 18V
−0.3V
to 6V
1.2A
0.926W
108°C/W
ACIN Input Voltage --------------------------------------------------------------------------------------------------------
EN Input Voltage -----------------------------------------------------------------------------------------------------------
Output Current -------------------------------------------------------------------------------------------------------------
Power Dissipation, P
D
@ T
A
= 25°C
WDFN-10L 3x3 -------------------------------------------------------------------------------------------------------------
Package Thermal Resistance (Note 2)
WDFN-10L 3x3,
θ
JA
-------------------------------------------------------------------------------------------------------
WDFN-10L 3x3,
θ
JC
------------------------------------------------------------------------------------------------------- 8.2°C/W
Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------- 260°C
Junction Temperature ---------------------------------------------------------------------------------------------------- 150°C
Storage Temperature Range --------------------------------------------------------------------------------------------
−65°C
to 150°C
ESD Susceptibility (Note 3)
HBM (Human Body Mode) ---------------------------------------------------------------------------------------------- 2kV
MM (Machine Mode) ------------------------------------------------------------------------------------------------------ 200V
Recommended Operating Conditions
(Note 4)
ACIN Input Voltage Range ----------------------------------------------------------------------------------------------- 4.5V to 6V
Junction Temperature Range --------------------------------------------------------------------------------------------
−40°C
to 125°C
Ambient Temperature Range --------------------------------------------------------------------------------------------
−40°C
to 85°C
Electrical Characteristics
(ACIN = 5V, T
A
= 27°C, Unless Otherwise specification)
Parameter
Supply Input
Symbol
Test Conditions
Min
--
50
Typ
4.4
80
300
50
150
2
Max
4.5
120
500
100
250
5
Units
V
mV
uA
uA
uA
uA
ACIN UVP Rising Threshold Voltage V
UV_HIGH
ACIN UVP Hysteresis
ACIN Standby Current
ACIN Shutdown Current
ACIN UVP Current
BATT Sleep Leakage Current
Voltage Regulation
BATT Regulation Voltage
Regulation Voltage Accuracy
ACIN MOSFET
Current Regulation
ISETA Set Voltage
(Fast Charge Phase)
Full Charge Setting Range
ACIN Charge Current accuracy
R
DS(ON)_ACIN
I
BATT
= 500mA
V
REG
I
BATT
= 60mA
V
UV_LOW
I
STBY
I
SHDN
I
UVP
I
SLEEP
V
BATT
= 4.5V
V
EN
= HIGH
V
ACIN
= 4V, V
USB
= 4V,
V
BATT
= 3V
V
ACIN
= 4V, V
USB
= 4V,
V
BATT
= 4.5V
--
--
--
--
4.158
−1
--
4.2
--
600
4.242
+1
--
V
%
mΩ
V
ISETA
I
CHG_AC
I
CHG_AC
V
BATT
= 3.5V
2.45
100
2.5
--
500
2.55
1200
--
V
mA
mA
V
BATT
= 3.8V,
R
ISET
= 1.5kΩ
--
To be continued
DS9505-02 April 2011
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