RT9536 - Richtek

®
RT9536
Linear Single Cell Li-Ion Battery Charger IC for Portable
Applications
General Description
Features
The RT9536 is a fully integrated single cell Li-ion battery
charger IC ideal for portable applications. The RT9536
optimizes the charging task by using a control algorithm
including pre-charge mode, fast charge mode and constant
voltage mode. The input voltage range of the VIN pin can
be as high as 28V. When the input voltage exceeds
the OVP threshold, it will turn off the charging MOSFET
to avoid overheating of the chip.








In RT9536, the maximum charging current can be
programmed with an external resistor. For USB application,
the user can set the current to 100mA/500mA through
the EN/SET pin. For the factory mode, the RT9536 can
allow 4.2V or 4.35V/2.3A power pass through to support
system operation. It also provides a 50mA LDO to support
the power of peripheral circuit. The internal thermal
feedback circuit regulates the die temperature to optimize
the charge rate for all ambient temperatures. The RT9536
provides protection functions such as under voltage
protection, over voltage protection for VIN supply and
thermal protection for battery temperature.


28V Maximum Rating for DC Adapter
Internal Integrated Power MOSFETs
Support 4.2V or 4.35V/2.3A Factory Mode
50mA Low Dropout Voltage Regulator
Status Pin Indicator
Programmed Charging Current
Under Voltage Lockout
Over Voltage Protection
Thermal Feedback Optimized Charge Rate
RoHS Compliant and Halogen Free
Applications



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Cellular Phones
Digital Cameras
PDAs and Smart Phones
Portable Instruments
Marking Information
03 : Product Code
03 YM
DNN
The RT9536 is available in a WDFN-10L 3x2 package to
achieve optimized solution for PCB space and thermal
considerations.
YMDNN : Date Code
Simplified Application Circuit
VIN
Adapter or USB
RT9536
BATT
CIN
BATT
PGB
RISET
RIEOC
Copyright © 2013 Richtek Technology Corporation. All rights reserved.
DS9536-00
June 2013
COUT
CHGSB
ISET
LDO
IEOC
EN/SET
+
BATT
GND
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RT9536
Ordering Information
Pin Configurations
RT9536
Package Type
QW : WDFN-10L 3x2 (W-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
VIN
ISET
GND
LDO
IEOC
1
2
3
4
5
GND
(TOP VIEW)
11
10
9
8
7
6
BATT
PGB
CHGSB
GND
EN/SET
Note :
Richtek products are :

WDFN-10L 3x2
RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.

Suitable for use in SnPb or Pb-free soldering processes.
Functional Pin Description
Pin No.
Pin Name
Pin Function
1
VIN
Power Input.
2
ISET
Charging Current Setting.
3, 7,
GND
11 (Exposed Pad)
Ground. The exposed pad must be soldered to a large PCB and connected to
GND for maximum power dissipation.
4
LDO
LDO Output (4.9V). This pin provides 50mA output current.
5
IEOC
End-of-Charge Current Setting. The IEOC is from 5% to 5O% Ichg-fast which is
programmed by the ISET pin.
6
EN/SET
Enable and Operation Mode and VOUT Regulation Voltage Setting.
8
CHGSB
Indicator Output for Charging Status.
9
PGB
Indicator Output for Power Status.
10
BATT
Battery Charge Current Output.
Function Block Diagram
Switch
Well
BATT
CHGSB
VIN
VREF
VDD
IBias
Base
Sleep
Mode
IEOC
IEOC Set
Block
PGB
CC/CV/TR
Multi Loop
Controller
Status
GND
Current
Set Block
ISET
Current
Set Block
EN/SET
200k
OVP
Logic
LDO
LDO
UVLO
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is a registered trademark of Richtek Technology Corporation.
DS9536-00
June 2013
RT9536
Operation
The RT9536 is designed for single cell Li-Ion battery charger
in portable applications.
Base Circuit
The Base circuit provides the internal power for VDD, VREF
reference voltage and bias current.
Multi-Loop Controller
The Multi-Loop controller controls the operation during
the charging process. The controller will make sure the
battery is well charged in a suitable current, voltage, and
die temperature.
Status Indicator
Power Switch with Switch Well Circuits
The main power switch between VIN and BATT is designed
to control the charge current for battery. The switch well
is designed to avoid the reverse current from battery to
input power.
Sleep Mode
When the charger is only connected to battery with no
input power, the charger will enter sleep mode and the
leakage current from battery to the charger will be less
than 10μA for low power consumption
Current Set Block
The charge current is adjustable from the ISET pin with
an external resistor between the ISET and GND. The Endof-Charge current is also adjustable by an external resistor
connected from the IEOC pin to GND. If the charging
current is less than EOC current, the CHGSB pin will be
pulled high.
Protection
The CHGSB and PGB pin indicate the charger and power
condition. During the charging process, the CHGSB pin
is pulled low. When the charger is under charge done
condition or abnormal condition, the CHGSB will be high
impedance. The PGB pin indicates the input power status
at VIN pin. When the input power is normal, the PGB pin
is pulled low.
Operation Mode
The RT9536 provides programmable output current mode
setting including USB100, USB500 and Factory mode.
The operation mode is programmable through the input
pulse number at EN/SET pin. Under the factory mode,
besides the EN/SET is also used to set regulation to be
4.2V or 4.35V. Output current is up to 2.3A.
LDO
The RT9536 provides a LDO regulator to support the
peripheral circuits. The output voltage is regulated to 4.9V
and the maximum output current is 50mA.
The protection circuits include OVP, UVLO and OTP. When
the protection circuit is triggered, the main power switch
will be turned of to protect the charging system.
Copyright © 2013 Richtek Technology Corporation. All rights reserved.
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June 2013
is a registered trademark of Richtek Technology Corporation.
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3
RT9536
Absolute Maximum Ratings







(Note 1)
Supply Input Voltage, VIN ----------------------------------------------------------------------------------------------- −0.3V to 28V
Other Pins ------------------------------------------------------------------------------------------------------------------- −0.3V to 6V
Power Dissipation, PD @ TA = 25°C
WDFN-10L 3x2 ------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2)
WDFN-10L 3x2, θJA ------------------------------------------------------------------------------------------------------WDFN-10L 3x2, θJC ------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Storage Temperature Range --------------------------------------------------------------------------------------------
Recommended Operating Conditions



2.27W
44°C/W
11°C/W
260°C
150°C
−65°C to 150°C
(Note 3)
Supply Input Voltage, VIN ----------------------------------------------------------------------------------------------- 4.3V to 5.5V
Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C
Ambient Temperature Range -------------------------------------------------------------------------------------------- −20°C to 85°C
Electrical Characteristics
(VIN = 5V, VBATT = 4V, TA = 25°C, unless otherwise specified)
Parameter
VIN POR Rising Threshold
Voltage
Symbol
Test Conditions
Min
Typ
Max
Unit
3.15
3.3
3.45
V
--
200
300
mV
6.7
6.9
7.1
V
--
200
300
mV
VIN VOUT VOS Rising
--
75
150
mV
VIN  VOUT VOS Falling
18
32
--
mV
VPOR
VIN POR Threshold Voltage
Hysteresis
VIN OVP Threshold Voltage
VIN OVP Threshold Voltage
Hysteresis
VOVP
VIN Standby Current
VBATT = 4.5V, EN/SET = High
--
250
300
A
VIN Supply Current
VBATT = 4.5V, EN/SET = Low
--
1
2
mA
--
1
10
A
4.158
4.2
4.242
4.307
4.35
4.393
Thermal Regulation
--
125
--
C
OTP
--
155
--
C
OTP Hysteresis
--
20
--
C
PGB/CHGSB Sink Current
20
--
--
mA
VOUT Rising; VCV = 4.2V
2.4
2.5
2.6
VOUT Rising; VCV = 4.35V
2.5
2.6
2.7
--
25
--
VOUT Sleep Leakage Current
VOUT Regulation
Pre-Charge Threshold
VCV
0C to 85C, ILOAD = 0mA
Fast-Charge to Pre-Charge
Deglitch Time
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V
V
ms
is a registered trademark of Richtek Technology Corporation.
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RT9536
Parameter
Symbol
IPRECHG
Pre-Charge Current
Test Conditions
Min
Typ
Max
Unit
USB100 Mode
90
95
100
mA
USB500 Mode or ISET Mode,
ratio of fast-charge current
15
20
25
%
--
%
70
REOC /
KEOC
75
80
A
180
200
220
/%
--
280
512
mV
--
1.5
--
V
320
--
460

--
1.5
--
ms
--
2
--
A
As ISET Mode, RISET = 530
0.9
1
1.1
A
As USB100 Mode
90
95
100
mA
As USB500 Mode
380
395
415
mA
--
200
--
k
End of Charge Current (EOC)
IEOC Setting Current
-IEOC
IEOC Setting KEOC
VIN Power FET RDS(ON)
ISET Set Voltage
IOUT = 1A
VISET
ISET Short Protect Threshold
ISET Short Protect Deglitch
Time
ISET Short Protect Maximum
Current
VIN Charge Current
ICHRG
EN/SET Pull Low Resistor
EN/SET Voltage
Logic-High
VIH
1.4
--
--
Logic-Low
VIL
--
--
0.4
3
6

4.75
4.9
5.05
V
60
120
180
mA
VCV = 4.2V
4.116
4.2
4.284
VCV = 4.35V
4.263
4.35
4.437
2.3
--
--
A
2
--
--
ms
1.5
--
--
ms
Logic-High
100
--
700
Logic-Low
100
--
700
750
--
1000
LDO On-Resistance
RDS(ON)
LDO Output Voltage
VLDO
LDO Maximum Output Current
Factory Mode VOUT
Factory Mode Maximum Output
Current
EN/SET Off Time
Timer to disable chip
EN/SET Lock Time
Timer to lock pulse count
EN/SET Duration
EN/SET Set Time
Timer to set VCV = 4.35V
V
V
s
s

Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are
stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in
the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may
affect device reliability.
Note 2. θJA is measured at TA = 25°C on a high effective thermal conductivity four-layer test board per JEDEC 51-7. θJC is
measured at the exposed pad of the package.
Note 3. The device is not guaranteed to function outside its operating conditions.
Copyright © 2013 Richtek Technology Corporation. All rights reserved.
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June 2013
is a registered trademark of Richtek Technology Corporation.
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RT9536
Typical Application Circuit
RT9536
1 VIN
Adapter or USB
BATT 10
CIN
BATT
COUT
9 PGB
CHGSB 8
2
LDO 4
EN/SET 6
3, 7, 11 (Exposed Pad)
GND
5
RISET
RIEOC
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+
ISET
IEOC
BATT
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June 2013
RT9536
Typical Operating Characteristics
VOUT Regulation Voltage vs. Input Voltage
VOUT Regulation Voltage vs. Temperature
4.215
4.220
4.215
4.210
4.205
4.200
VCV = 4.2V
VOUT Regulation Voltage (V)1
VOUT Regulation Voltage (V)
4.225
4.210
4.205
4.200
4.195
4.190
VCV = 4.2V, VIN = 5V
4.185
4.195
4.5
4.94
5.38
5.82
6.26
-50
6.7
-25
0
VOUT Regulation Voltage vs. Input Voltage
75
4.366
4.362
4.358
4.354
125
4.365
4.360
4.355
4.350
4.345
VCV = 4.35V
VCV = 4.35V
4.340
4.350
4.5
4.94
5.38
5.82
6.26
-50
6.7
-25
0
Input Voltage (V)
Input OVP Threshold vs. Temperature
6.80
6.78
6.76
6.74
6.72
6.70
-25
0
25
50
75
100
Temperature (°C)
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June 2013
50
75
100
125
VOUT Sleep Leakage Current vs. Battery Voltage
VOUT Sleep Leakage Current (µA)1
6.82
-50
25
Temperature (°C)
6.84
DS9536-00
100
VOUT Regulation Voltage vs. Temperature
VOUT Regulation Voltage (V)
VOUT Regulation Voltage (V)1
50
4.370
4.370
Input OVP Threshold (V)
25
Temperature (°C)
Input Voltage (V)
125
20
16
12
8
4
0
1.3
1.7
2.1
2.5
2.9
3.3
3.7
4.1
4.5
Battery Voltage (V)
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RT9536
LDO Voltage vs. Temperature
4.95
4.93
4.93
LDO Voltage (V)
LDO Output Voltage (V)
LDO Output Voltage vs. Output Current
4.95
4.91
4.89
4.91
4.89
4.87
4.87
VIN = 5.5V, ILDO = 50mA
VIN = 5.5V
4.85
4.85
0
20
40
60
80
100
-50
-25
Output Current (mA)
0
25
50
75
100
125
Temperature (°C)
ISET Mode Charge Current vs. Input Voltage
USB 500 Mode Charge Current vs. Input Voltage
900
415
R = 680
750
Charge Current (mA)
Charge Current (mA)
825
675
600
525
450
R = 1.2k
405
395
385
375
375
VBATT = 3.8V
VBATT = 3.8V
300
365
4.5
4.9
5.3
5.7
6.1
6.5
4.5
4.9
Input Voltage (V)
5.3
5.7
6.1
6.5
Input Voltage (V)
USB 100 Mode Charge Current vs. Input Voltage
ISET Voltage vs. Input Voltage
100
1.53
ISET Voltage (V)
Charge Current (mA)
1.52
95
90
1.51
1.50
1.49
1.48
RISET = 1.2kΩ, VBATT = 3.8V
VBATT = 3.8V
85
1.47
4.5
4.9
5.3
5.7
6.1
Input Voltage (V)
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6.5
4.2
4.72
5.24
5.76
6.28
6.8
Input Voltage (V)
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RT9536
Power On
EN/SET Shut-Down
VIN
(5V/Div)
EN/SEB
(1V/Div)
PGB
(2V/Div)
CHGSB
(2V/Div)
VLDO
(2V/Div)
CHGS
(2V/Div)
I CHARGER
(500mA/Div)
I CHARGER
(500mA/Div)
VBATT = 3.8V, RISET = 680Ω, EN/SEB = Low
VIN = 5V
Time (10ms/Div)
Charger Current--USB500 mode to ISET mode
Time (1ms/Div)
Charger Current--USB500 mode to USB100 mode
VIN
(5V/Div)
VBATT
(5V/Div)
EN/SET
(2V/Div)
VIN
(5V/Div)
VBATT
(5V/Div)
EN/SET
(2V/Div)
I CHARGER
(500mA/Div)
I CHARGER
(500mA/Div)
VIN = 5V, VBATT = 3.8V, RISET = 680Ω
VIN = 5V, VBATT = 3.8V, RISET = 680Ω
Time (1ms/Div)
Time (1ms/Div)
LDO Load Transient Response
Factory Mode
VIN
(5V/Div)
VBATT
(200mV/Div)
EN/SET
(1V/Div)
VLDO_ac
(100mV/Div)
I LDO
(500mA/Div)
IOUT
(1A/Div)
VIN = 5V, VBATT = 3.8V, ILDO = 5mA to 50mA
Time (250μs/Div)
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June 2013
VIN = 5V, COUT = 44μF, IOUT = 10Ω to 2.3Ω
Time (50μs/Div)
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RT9536
Application Information
Description
The RT9536 is a fully integrated low cost single-cell LiIon battery charger IC with a Constant Current mode (CC
mode) or a Constant Voltage mode (CV mode). The charge
current is programmable to USB100, USB500 or ISET
mode and the CV mode voltage is fixed at 4.2V/4.35V.
The pre-charge threshold is fixed at 2.5V/2.64V. If the
battery voltage is below the pre-charge threshold, the
RT9536 charges the battery with a trickle current until
the battery voltage rises above the pre-charge threshold.
The RT9536 is capable of being powered up from AC
adapter and USB (Universal Serial Bus) port inputs.
Moreover, the RT9536 include a linear regulator (LDO 4.9V,
50mA) for supplying low power external circuitry.
period of pulse to pulse must be between 100μs and 700μs
to be properly read. Once EN/SET is held low for 1.5ms,
the number of pulses is locked and sent to the control
logic and then the mode changes. After the setting of
charging current is completed, sending the pulse can set
CV mode voltage to be 4.35V. The RT9536 needs to be
restarted to reset the charge current. Once the EN/SET
input is held high for more than 2ms, the RT9536 is
disabled.
A. USB500 Mode with CV = 4.2V
No pulse to set
USB500 mode
EN/SET
tHigh
Four pulses to set
USB500 mode
EN/SET
ACIN Over Voltage Protection
The input voltage is monitored by the internal comparator
and the input over voltage protection threshold is set to
6.9V. However, input voltage over 28V will still cause
damage to the RT9536. When the input voltage exceeds
the threshold, the comparator outputs a logic signal to
turn off the power P-MOSFET to prevent the high input
voltage from damaging the electronics in the handheld
system. When the input over voltage condition is removed,
the comparator re-enables the output by running through
the soft-start.
tLow
B. ISET Mode with CV = 4.2V
tHigh
C. USB100 Mode with CV = 4.2V
tHigh
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Two pulses to set
USB100 mode
EN/SET
tLow
D. PTM Mode with CV = 4.2V
tHigh
Charger Enable and mode Setting
EN/SET is used to enable or disable the charger as well
as to select the charge current limit. Drive the EN pin to
low or leave it floating to enable the charger. The EN/SET
pin has a 200kΩ internal pull down resistor. So, when left
floating, the input is equivalent to logic low. Drive this pin
to high to disable the charger. After the EN/SET pin pulls
low for 50μs, the RT9536 enters the USB500 mode and
wait for the setting current signal. EN/SET can be used
to program the charge current during this cycle. The
RT9536 will change its charge current by sending different
pulse to EN/SET pin. If no signal is sent to EN/SET, the
RT9536 will remain in USB500 mode. A correct period of
time for high pulse is between 100μs and 700μs and the
One pulse to set
ISET mode
EN/SET
Three pulses to set
PTM mode
EN/SET
tLow
100μs < tHigh, tLow < 700μs
Figure 1 (a). CV is 4.2V
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RT9536
E. USB500 Mode with CV = 4.35V
tHigh
tCV_Set
Four pulses to set USB500 mode
Besides, wait the time, tWait and send a
pulse of tCV_SET width for CV = 4.35V
EN/SET
tWait
tLow
F. ISET Mode with CV = 4.35V
tHigh
One pulse to set ISET mode
Besides, wait the time, tWait and send a
tCV_Set
EN/SET
pulse of tCV_SET width for CV = 4.35V
tWait
G. USB100 Mode with CV = 4.35V
tCV_Set
tHigh
EN/SET
Two pulses to set USB100 mode
Besides, wait the time, tWait and send a
pulse of tCV_SET width for CV = 4.35V
tWait
H. PTM Mode with CV = 4.35V
tHigh
tCV_Set
Three pulses to set PTM mode
Besides, wait the time, tWait and send a
pulse of tCV_SET width for CV = 4.35V
EN/SET
tLow
tWait
100μs < tHigh,tLow < 700μs, 1.5ms < tWait 750μs < tCV_Set < 1ms
Figure 1 (b). CV is 4.35V
Table 1. Pulse Counting Map for EN/SET Interface
Pulses
Charge Condition
MODE Control
0
USB500 Mode
Charge Current Limit
1
ISET Mode
Charge Current Limit
2
USB100 Mode
Charge Current Limit
3
Factory Mode
Enabled
4
USB500 Mode
Charge Current Limit
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RT9536
Battery Charge Profile
Battery Fast-Charge Current
The RT9536 charges a Li-Ion battery with a Constant
Current (CC) or a Constant Voltage (CV).
ISET Mode
The constant current is decided by the operation mode of
USB100, USB500 or ISET mode. The constant current is
set with the external resistor RISET and the constant voltage
is fixed at 4.2V/4.35V. If the battery voltage is below the
Pre-Charge Threshold, the RT9536 charges the battery
with a trickle current until the battery voltage rises above
the trickle charge threshold. When the battery voltage
reaches 4.2V/4.35V, the charger enters CV mode and
regulates the battery voltage at 4.2V/4.35V to fully charge
the battery without the risk of over charging
1400
Constant
Current
Mode
Battery
Charge
Current
Programmed
Charge
Current
Constant
Voltage
Mode
Recharge
Phase
4.2V/4.35V
Battery
Regulation
Voltage
threshold
Battery Charge Current (mA)
Pre-charge
Mode
The RT9536 offers ISET pin to program the charge current.
The resistor RISET is connected to ISET and GND. The
parameter KISET is specified in the specification Table.
K
ICharge = ISEF ; KISEF = 530
RISET
1200
1000
800
600
400
200
0
0.4 0.6 0.8
1 1.2 1.4 1.6 1.8
2 2.2 2.4 2.6 2.8
3
RSET (k)
(kΩ)
Figure 3
Battery
Full
CHG_S
pull High
USB500 and USB100 Mode
Precharge
Threshold
Time
Figure 2
The fast-charge current is 95mA in USB100 mode and
395mA in USB500 mode. Note that if the fast-charge
current set by external resistor is smaller than that in
USB500 mode (395mA), the RT9536 charges the battery
in ISET mode.
Battery Voltage Regulation (CV Mode)
Battery Pre-Charge Current
During a charge cycle, if the battery voltage is below the
pre-charge threshold, the RT9536 enters the pre-charge
mode. This feature revives deeply discharged cells and
protects battery. Under USB100 Mode, the pre-charge
current is internally set to 95mA. When the RT9536 is
under USB500 and ISET Mode, the pre-charge current is
20% of fast-charge current set by external resistor RISET.
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The battery voltage regulation feedback is through the
BATT pin. The RT9536 monitors the battery voltage
between BATT and GND pins. When the battery voltage
closes in on the battery regulation voltage threshold, the
voltage regulation phase begins and the charging current
begins to taper down. When the charging current falls
below the programmed end-of-charge current threshold,
the CHGSB pin goes high to indicate the termination of
charge cycle.
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RT9536
The end-of-charge current threshold is set by the IEOC
pin. The resistor REOC is connected to IEOC and GND.
The parameters KEOC and IEOC are specified in the
specification Table.
R
IEOC (%) = EOC ; KEOC = 200
KEOC
The current threshold of IEOC (%) is defined as the
percentage of fast-charge current set by RISET. After the
CHGSB pin is pulled high, the RT9536 still monitors the
battery voltage. Charge current is resumed when the
battery voltage goes to lower than the battery regulation
voltage threshold.
Factory Mode
The RT9536 provides factory mode for supplies up to 2.3A
for powering external loads with no battery installed and
BATT is regulated to 4.2V. The factory mode allows the
user to supply system power with no battery connected.
In factory mode, thermal regulation is disabled but thermal
protection (155°C) is still active. When using currents
greater than 1.5A in factory mode, the user must limit the
duty cycle at the maximum current to 20% with a
maximum period of 10ms.
LDO
The RT9536 integrates one low dropout linear regulator
(LDO) that supplies up to 50mA. The LDO is active
whenever the input voltage is between POR threshold and
OVP threshold. It is not affected by the EN/SET input.
Note that the LDO current is independence and not
monitored by the charge current limit.
Charge Status Outputs (CHGSB and PGB)
The open-drain CHGSB and PGB outputs indicate various
charger operations as shown in the following Table. These
status pins can be used to drive LEDs or communicate to
the host processor. Note that ON indicates the open-drain
transistor is turned on and LED is bright.
Copyright © 2013 Richtek Technology Corporation. All rights reserved.
DS9536-00
June 2013
Table 2
Condition
CHGSB
Input OVP
OFF
Input UVLO
OFF
Charge (CC Mode and CV Mode)
ON
Charge Done (IFULL)
OFF
PGB
OFF
OFF
ON
ON
PGB Deglitches Time
Condition
EN/SET is
High
EN/SET is
Low
0
100s
500s
450s
0
32ms
500s
500s
Entering UVLO
(VIN = 5.5V2.5V)
0
0
Leaving UVLO
(VIN = 2.5V5.5V)
230s
230s
Entering OVP
(VIN = 5.5V10V)
Leaving OVP
(VIN = 10V5.5V)
Entering SLEEP
(VIN = 5.5V3.6V)
Leaving SLEEP
(VIN = 3.6V5.5V)
Sleep Mode
The RT9536 enters sleep mode if the power is removed
from the input. This feature prevents draining the battery
during the absence of input supply.
Temperature Regulation and Thermal Protection
In order to maximize charge rate, the RT9536 features a
junction temperature regulation loop. If the power
dissipation of the IC results in a junction temperature
greater than the thermal regulation threshold (125°C), the
RT9536 limits the charge current in order to maintain a
junction temperature around the thermal regulation
threshold (125°C). The RT9536 monitors the junction
temperature, TJ, of the die and disconnects the battery
from the input if TJ exceeds 125°C. This operation
continues until junction temperature falls below thermal
regulation threshold (125°C) by the hysteresis level. This
feature prevents maximum power dissipation from
exceeding typical design conditions.
is a registered trademark of Richtek Technology Corporation.
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RT9536
2.5
Maximum Power Dissipation (W)1
Selecting the Input and Output Capacitors
In most applications, all that is needed is a high-frequency
decoupling capacitor on the input. A 1μF ceramic capacitor,
placed in close proximity to input to GND, works well. In
some applications depending on the power supply
characteristics and cable length, it may be necessary to
add an additional 10μF ceramic capacitor to the input.
The RT9536 requires a small output capacitor for loop
stability. A typical 1μF ceramic capacitor placed between
the BATT pin and GND is sufficient.
Four-Layer PCB
2.0
1.5
1.0
0.5
0.0
0
Thermal Considerations
PD(MAX) = (TJ(MAX) − TA) / θJA
where T J(MAX) is the maximum operation junction
temperature, TA is the ambient temperature, and θJA is the
junction to ambient thermal resistance.
For recommended operating condition specifications, the
maximum junction temperature is 125°C. The junction to
ambient thermal resistance, θJA, is layout dependent. For
WDFN-10L 3x2 package, the thermal resistance, θJA, is
44°C/W on a standard JEDEC 51-7 four-layer thermal test
board. The maximum power dissipation at TA = 25°C can
be calculated by the following formula :
P D(MAX) = (125°C − 25°C) / (44°C/W) = 2.27W for
WDFN-10L 3x2 package
The maximum power dissipation depends on the operating
ambient temperature for fixed T J(MAX) and thermal
resistance, θJA. The derating curve in Figure 4 allows the
designer to see the effect of rising ambient temperature
on the maximum power dissipation.
50
75
100
125
Ambient Temperature (°C)
Figure 4. Derating Curve of Maximum Power Dissipation
Layout Consideration
The RT9536 is a fully integrated low cost single-cell LiIon battery charger IC ideal for portable applications. Careful
PCB layout is necessary. For best performance, place all
peripheral components as close to the IC as possible. A
short connection is highly recommended. The following
guidelines should be strictly followed when designing a
PCB layout for the RT9536.

Input capacitor should be placed close to the IC and
connected to ground plane. The trace of input in the
PCB should be placed far away from the sensitive devices
or shielded by the ground.

The GND should be connected to a strong ground plane
for heat sinking and noise protection.

The connection of RISET and RIEOC should be isolated
from other noisy traces. The short wire is recommended
to prevent EMI and noise coupling.

Output capacitor should be placed close to the IC and
connected to ground plane to reduce noise coupling.
The capacitor should be placed close to
IC pin and connected to ground plane.
The connection of
resistor should be
isolated from other
noisy traces. Short
wire is recommended
to prevent EMI and
noise coupling.
CIN
RISET
VIN
ISET
GND
LDO
IEOC
1
2
3
4
5
GND
For continuous operation, do not exceed absolute
maximum operation junction temperature. The maximum
power dissipation depends on thermal resistance of the
IC package, PCB layout, rate of surrounding airflow, and
difference between junction and ambient temperature. The
maximum power dissipation can be calculated by the
following formula :
25
11
10
9
8
7
6
BATT
PGB
CHGSB
GND
EN/SET
COUT
RIEOC
GND
The GND should be connected to a strong ground
plane for heat sinking and noise protection.
Figure 5. Layout Guide
Copyright © 2013 Richtek Technology Corporation. All rights reserved.
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14
is a registered trademark of Richtek Technology Corporation.
DS9536-00
June 2013
RT9536
Outline Dimension
D2
D
L
E2
E
1
e
A
A1
SEE DETAIL A
b
A3
2
1
2
1
DETAIL A
Pin #1 ID and Tie Bar Mark Options
Note : The configuration of the Pin #1 identifier is optional,
but must be located within the zone indicated.
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
0.700
0.800
0.028
0.031
A1
0.000
0.050
0.000
0.002
A3
0.175
0.250
0.007
0.010
b
0.180
0.300
0.007
0.012
D
2.900
3.100
0.114
0.122
D2
2.450
2.550
0.096
0.100
E
1.900
2.100
0.075
0.083
E2
0.750
0.850
0.030
0.033
e
L
0.500
0.250
0.020
0.350
0.010
0.014
W-Type 10L DFN 3x2 Package
Richtek Technology Corporation
5F, No. 20, Taiyuen Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789
Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should
obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot
assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be
accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries.
DS9536-00
June 2013
www.richtek.com
15