MPS MP26075EQ High efficiency cradle charger Datasheet

MP26075
High Efficiency Cradle Charger
The Future of Analog IC Technology
FEATURES
DESCRIPTION
The MP26075 is a linear, high performance,
and high efficiency single cell Li-Ion or Lipolymer battery charger for AC adapter input in
the plug-in, cradle charger applications.
The device will control the AC adapter output
voltage against the battery voltage to increases
energy efficiency. Additionally, MP26075 can
provide very low pre-charge charge current for
deep-discharged battery.
For guaranteed safe operation, MP26075
controls power up sequencing. It ramps-up AC
adapter firstly to limit inrush current when the
adapter plug in. Other safety feature includes
battery temperature monitoring, charge time-out
and fault indications, it also provides
input/output over voltage protection and charge
status indications.
MP26075 is available in QFN 3x3mm package.












Voltage control function for the fly-back
controller
High charge efficiency
Battery voltage options: 4.05V-4.20V.
Low current pre-charge mode
Controlled power-up sequencing
Battery temperature monitoring
Charge status indication
Auto-Recharge
Fault indications
Internal timer
Input/output OVP
Over temperature protection
APPLICATIONS





Cell Phones
Portable Music Players
Smart Phones
PDA
Digital Cameras
For MPS green status, please visit MPS website under Quality Assurance.
“MPS” and “The Future of Analog IC Technology” are Registered Trademarks
of Monolithic Power Systems, Inc.
TYPICAL APPLICATION
CIN
VIN
LED-R
LED-G
GND
BATT
MP26075NTC
CTL
TMR
COM
ISET
Battery
Pack
COUT
RNTC
Photo-Coupler
MP26075 Rev. 1.01
www.MonolithicPower.com
5/23/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
1
MP26075 – HIGH EFFICIENCY CRADLE CHARGER
ORDERING INFORMATION
Part Number*
Battery Voltage
MP26075EQ
4.20V
MP26075EQ-41**
4.10V
Package
QFN10 (3x3mm)
Top Marking
8N
Free Air Temperature (TA)
–20C to +85C
ACC
* For Tape & Reel, add suffix –Z (e.g. MP26075EQ–Z);
For RoHS Compliant Packaging, add suffix –LF (e.g. MP26075EQ–LF–Z)
** MP26075 has several options with different battery voltages.
Please refer to the ordering information list. And Contact factory for other battery voltages.
PACKAGE REFERENCE
ABSOLUTE MAXIMUM RATINGS (1)
Thermal Resistance
VIN to GND .................................. –0.3V to +28V
LED-R and LED-G Maximum Sink Current .... 20mA
All Other Pins to GND ..................-0.3V to +6.5V
Continuous Power Dissipation (TA = +25°C)
3x3 QFN10 ............................. 50 ...... 12... C/W
(2)
............................................................. 2.5W
Junction Temperature ...............................140C
Lead Temperature ....................................260C
Storage Temperature .............. –65°C to +150C
Recommended Operating Conditions
(3)
Supply Voltage VIN .......................... 2.2V to 6.3V
Maximum Junction Temp. (TJ). .............. +125C
(4)
θJA
θJC
Notes:
1) Exceeding these ratings may damage the device.
2) The maximum allowable power dissipation is a function of the
maximum junction temperature TJ(MAX), the junction-toambient thermal resistance θJA, and the ambient temperature
TA. The maximum allowable continuous power dissipation at
any ambient temperature is calculated by PD(MAX)=(TJ(MAX)TA)/ θJA. Exceeding the maximum allowable power dissipation
will cause excessive die temperature, and the regulator will go
into thermal shutdown. Internal thermal shutdown circuitry
protects the device from permanent damage.
3) The device is not guaranteed to function outside of its
operating conditions.
4) Measured on JESD51-7 4-layer board.
MP26075 Rev. 1.01
www.MonolithicPower.com
5/23/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
2
MP26075 – HIGH EFFICIENCY CRADLE CHARGER
ELECTRICAL CHARACTERISTICS (5)
VIN=5V (fast charge state not included), TA=-20°C to +85°C, Typical values are at TA=+25°C,
unless otherwise noted.
Parameter
Battery Voltage
Regulation
Symbol
4.20V
4.15V
4.10V
4.05V
Constant Current Regulation
VBATT
ICHG
Constant Current Variation
Trickle current regulation
ICHG
Condition
Min
Typ
Max
Units
TA=-5°C to +75°C
IBATT=0A
4.16
4.11
4.06
4.01
4.20
4.15
4.10
4.05
4.24
4.19
4.14
4.09
V
0.85
1
1.2
A
85
100
120
%
85
100
120
mA
VIN=5V,VBATT=3.8V,
RCHG=1.7k
VIN=5V,VBATT=3.8V,
TA=0°C to 85°C
RCHG=1.7k~8.0k
VIN=5V,VBATT=2.5V
RCHG=1.7k
When VBATT<3V
Input voltage regulation
VIN
VIN-VBATT during fast charge state
When VBATT>3V,
ICHG>100mA
When VBATT>3V,
ICHG<100mA
VBATT=3.8V
5
V
VBATT+0.5V
V
5
V
500
mV
Input UVLO threshold
VIN
1.5
2.0
2.5
V
UVLO hysteresis
Input OVP threshold
Input OVP hysteresis
VIN
6.1
200
6.3
500
6.5
mV
V
mV
Output over voltage
threshold
VBATT=4.2V
VBATT-OVP VIN=4.85V
4.25
4.35
4.5
V
VBATT=4.1V
VBATT-OVP VIN=4.85V
4.15
4.25
4.4
V
2.1
V
V
V
mA
mA
μA
Battery Pre-charge Range
Battery Trickle-charge Threshold
Battery Fast-charge Threshold
LED RED sink current
LED GREE sink current
BATT reverse current to BATT PIN
Recharge Voltage attenuate from
VBATT
Vpre-Charge VIN=5V
VTC-CHarge VIN=5V
VFast-Charge VIN=5V
PIN voltage=0.2V
PIN voltage=0.2V
VIN = 0 or floating
NTC High Threshold
VNTC_HIGH VIN=5V
NTC High Trip Hysteresis
NTC Low Threshold
2.1
3
8
8
2
VIN=5V
VNTC_LOW VIN=5V
NTC Low Trip Hysteresis
VIN=5V
Timer frequency
CTMR=0.1μF
Die temperature Limit
0
(5)
8
%VBATT
2.16
V
78
mV
0.37
V
30
mV
7
Hz
120
°C
Notes:
5) Guaranteed by design
MP26075 Rev. 1.01
www.MonolithicPower.com
5/23/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
3
MP26075 – HIGH EFFICIENCY CRADLE CHARGER
PIN FUNCTIONS
Pin #
1
2
Name Description
VIN
Input Supply Pin. Decoupling Capacitor is needed to prevent large voltage spikes.
Open-Drain Charge status Indicator. This pin is high during charge and fault condition, is low
LED-G
after battery full or termination.
3
LED-R
Open-Drain Charge status Indicator. This pin is low during charge, is high after battery full or
termination and fault condition.
4
TMR
Pin of the oscillator. Connect a capacitor from this pin to GND to set the oscillator cycle. Timer
setting time changes according to oscillation cycle.
5
GND
GND pin.
6
COM
Compensation for VIN limits circuit.
7
CTL
8
ISET
9
NTC
10
BATT
CTL is used for VIN control. Connect to the cathode of photo diode of photo coupler by a
resistor.
Connect a resistor R between ISET and GND of Battery Pack to set the charge current.
Battery temperature monitoring pin. Connect a resistor from this pin to VIN and connect this pin
to the thermistor pin of the battery pack.
Charger Output terminal.
MP26075 Rev. 1.01
www.MonolithicPower.com
5/23/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
4
MP26075 – HIGH EFFICIENCY CRADLE CHARGER
TYPICAL PERFORMANCE CHARACTERISTICS
Test with AC_IN=220V flyback, CIN = 4.7μF, COUT = 10μF, ICHG = 1000mA, unless otherwise noted.
Charge Input Voltage vs
Charge Current vs
Real Battery Charge Curve
Battery Voltage
Battery Voltage
6
1.2
1200
1
1000
Input Voltage
5
5.5
ICHG=1000mA
5
800
4
0.8
3
0.6
600
2
0.4
400
1
0.2
200
Battery Current
0
0
10
20
30
40
50
60
0
ICHG=600mA
4.5
4
ICHG=300mA
3.5
0
1.5
2
2.5
3
3.5
4
3
4.5
1.5
Battery Reverse Current
IBATT vs VBATT Curve
Constant Current charge,
100
0.08
800
80
600
400
0.02
200
1
2
3
VBATT(V)
4
5
ICHG (mA)
1000
ICHG(mA)
0.1
0.04
0
0
140
4
4.5
60
40
20
0
2
4
6
8
Constant Current charge ,
VBATT=3.8V
TJ
110
0
10
CC Charge Current
vs. Temp
0.61
0.6
0.59
0.58
0.57
0.56
0.55
0.54
0.53
0.52
0.51
0.5
20
3.5
Trickle charge, VBATT=2.4V
VBATT=3.8V
120
0.06
3
RCHG vs. ICHG Curve
RCHG vs. ICHG Curve
VIN=GND, Power Source on BATT
0
0
2.5
VBATT(V)
1200
0.12
2
VBATT(V)
TIME(Min)
IBATT(uA)
VIN(V)
IBATT(A)
IBATT(mA)
VIN&VBATT(V)
Battery Voltage
2
8
10
The junction temperature is too high.
Part enters thermal foldback mode
140
120
TA
6
CC Charge Current vs.
Temp Zoom In
TJ
80
50
4
100
20
80
-10
40
60
80
100 120 140
-40
700
TA
800
900 1000 1100 1200
IBATT (mA)
60
700
800
900 1000 1100 1200
IBATT (mA)
MP26075 Rev. 1.01
www.MonolithicPower.com
5/23/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
5
MP26075 – HIGH EFFICIENCY CRADLE CHARGER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
Test with AC_IN=220V flyback, CIN_CHARGER = 4.7μF, COUT_CHARGER = 10μF, ICHG = 1000mA, unless
otherwise noted.
Input Power Start Up
Input Power Shut Down
Auto Re-charge
Real Battery, VBATT=3.8V
Real Battery, VBATT=3.8V
Battery Float
VBATT
2V/div.
VBATT
2V/div.
VIN
2V/div.
VIN
2V/div.
IBATT
500mA/div.
IBATT
500mA/div.
40
v.
LED-R
2V/div.
LED-G
2V/div.
VBATT
2V/div.
IBATT
200mA/div.
2s/div.
10 s/div.
NTC Window Control
Input OVP Entry
Timer Out
VBATT=3.8V,
CV Load VNTC from 0V to 2.5V
Open flyback Loop,
VBATT=3.8V, VIN from 5V to 7V
VBATT=2.1V, CTMR=100pF
VTMR
500mV/div.
VNTC
2V/div.
VBATT
2V/div.
VBATT
2V/div.
VIN
2V/div.
VIN
2V/div.
VBATT
2V/div.
VIN
2V/div.
IBATT
1A/div.
IBATT
500mA/div.
IBATT
50mA/div.
v.
100 s/div.
MP26075 Rev. 1.01
www.MonolithicPower.com
5/23/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
v.
6
MP26075 – HIGH EFFICIENCY CRADLE CHARGER
BLOCK DIAGRAM
VIN
CIN
BATT
+
+
Battery
LED-R
Thermal
Shutdown
NTC
NTC
LED-G
Adaptor Over
Voltage
Detection
CTL
GND
Adaptor Under
Voltage
Detection
Charge
Control
VCC
Control
COM
ISET
TMR
ISET
OSC
Timer
Figure 1— Function Block Diagram
MP26075 Rev. 1.01
www.MonolithicPower.com
5/23/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
7
MP26075 – HIGH EFFICIENCY CRADLE CHARGER
OPERATION
The high-efficiency linear charger is mainly for
plug-in, cradle charger applications. The device
features using a photo-coupler to directly
feedback the charge voltage and charge current
information to the primary side. It is
recommended to use with flyback controller for
smooth system setup.
AC
Input
Figure 2 is the typical configuration for the
charger with photo-coupler feedback to control
the AC adapter. The voltage change of the CTL
pin will be transferred to the comp pin of the AC
adapter controller by the photo-coupler, which
controls the conduction time of the primary side
switch. The output voltage at secondary side of
the transformer is then adjusted.
VIN
LED-R
LED-G
MP26075
GND
BATT
NTC
EMI
Filter+
Rectifier
CTL
COM
Fly-back
Controller
COMP
TMR
ISET
COUT
Single Cell
Battery
RNTC
Photo-Coupler
Figure 2— System Configuration
Input Voltage Range
The MP26075 has built-in input voltage surge
protection as high as ±28V. The charger IC will
be automatically disabled when the input voltage
is lower than 2.2V or higher than 6.3V. If the
input voltage is lower than the battery voltage,
the IC is also disabled to prevent the battery from
draining. The MP26075 includes a proprietary
input reverse polarity circuit that eliminates the
requirement for an external Schottky diode.
Charge Cycle (Mode Change: Precharge->
Trickle -> CC-> CV)
Figure 3 below shows the typical charge profile
for the MP26075. For a fully depleted battery with
a terminal voltage lower than 2.1V, the MP26075
will start with 1mA pre-charge. If the charger
stays in the pre-charge mode longer than 512
cycles, LED-R and LED-G pins become high to
indicate the battery fault, and the charge is
terminated. And when battery voltage reaches
2.1V the MP26075 will start the trickle charge
(preconditioning) at 10% of the full charge current
based on the value of RCHG. If the charger stays
in the trickle mode longer than 16384 cycles,
LED-R and LED-G pins become high to indicate
battery fault, and the charge is terminated. After
the battery voltage reaches 3.0V, the charger
begins charge at the constant current of the
programmed value (ICHG). This is referred to as
the constant current (CC) mode. Once the
battery voltage reaches the battery regulation
voltage (e.g.4.2V), the charger will operate in the
constant voltage (CV) mode until the battery is
fully charged. The charge current drops during
CV mode, and the battery full indication is set
when the charge current reduced to 10% of the
programmed constant current value (ICHG), and
the charge process is terminated. Recharge will
start after the battery voltage is reduced to 8% of
VBATT. After 262144 cycles of continuous charge,
if the battery is still not reaching 10% of ICHG
MP26075 Rev. 1.01
www.MonolithicPower.com
5/23/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
8
MP26075 – HIGH EFFICIENCY CRADLE CHARGER
condition, the on-chip timer will terminate the
charger to prevent charging the dead battery for
excessive long time and the fault condition will be
flagged by floating LED-R and LED-G pins.
Charge Termination
The charge current will gradually decrease in CV
mode as the battery approaches full. The battery
full threshold is internally programmed to be 10%
of the ICHG. When the charge current reaches this
threshold, the charger IC will be automatically
turned off.
Automatic Recharge
Upon VBATT drops to 8% of VBATT, the charger will
automatically restart the charge cycle until the
10% ICHG condition is met again. When the input
adapter is unplugged or the charger is disabled
and/or terminated, the leakage current from the
battery to MP26075 is less than 2μA.
Programming of Charge Current
The charge current (ICHG) is set by a resistor
(RCHG) connecting from the ISET pin to GND. The
relationship of the charge current and the
programming resistance is established by the
following formula.
ICHG 
1.23V
 1400(A)
R CHG (k)
Timer Operation
The TMR pin is used to set the internal oscillator
frequency, T=900000*CTMR (sec). The on-chip
timer will start count down after initial power-up
or every time being enabled. This timer will limit
the max pre-charge time to 512 internal cycles
and max trickle-charge time to 16384 internal
oscillating cycles. If the charger stays in precharge mode for longer than 512 cycles or in
trickle mode for longer than 16384 cycles, it will
be terminated and a fault will be set by floating
LED-R and LED-G pins. After fault reporting, the
charger can be re-initiated only by recycling the
power supply. If the charger successfully goes
through trickle charge within the allowed time
limit, it will start CC charge and then CV charge.
If the total charge time exceeds 262144 cycles
and the battery full has not been qualified, the
charger will be terminated and a fault will also be
set by floating LED-R and LED-G pins. This
function prevents charging a dead battery for
prolonged duration. The timer function can be
disabled by shorting TMR pin to ground.
Table1— Timer of Each Times
Item
Calculation formula
1mA charge timer
Tx512
Trickle charge timer
Tx16384
Total charge timer
Tx262144
Negative Thermal Coefficient (NTC)
Thermistor
The MP26075 has a built-in NTC resistance
window comparator, which allows MP26075 to
sense the battery temperature via the thermistor
packed internally in the battery pack to ensure a
safe operating environment of the battery. A
resistor with appropriate value should be
connected from VIN to NTC pin and the
thermistor is connected from NTC pin to GND.
The voltage on NTC pin depends on the ratio of
the resistor divider. When the voltage of pin NTC
falls out of the NTC window range, MP26075 will
stop the charge. The charger will restart if the
temperature goes back into the NTC window
range.
Thermal Protection
The MP26075 has proprietary thermal protection
to prevent the IC from overheating. When in
thermal protection mode, the average charge
current will be reduced to prevent the IC from
overheating. Operating in thermal protection
mode will slow down the charge process.
Lowering the input voltage and enhancing
thermal dissipation to the environment can
effectively prevent the IC from going into thermal
protection mode.
Status Indication
MP26075 has two open-drain status outputs:
LED-R and LED_G. Both LED-R and LED-G are
used to indicate the status of the charge cycle.
Table 2 describes the status of the charge cycle
based on the LED-R and LED_G outputs. The
LED-R and LED_G pins pull high when any fault
happens.
MP26075 Rev. 1.01
www.MonolithicPower.com
5/23/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
9
MP26075 – HIGH EFFICIENCY CRADLE CHARGER
Table 2— Charge Status Indication
LED-R
High
Low
High
LED-G
High
High
Low
Compensation
Status
Fault/toggle
Normal charge
End of charge
PreTrickle
Charge Charge
COM pin is used to compensation Vin control
loop. Connect a Resistor and a capacitor
between COM pin and CTL pin to keep system’s
stability. 100nF capacitor and several kilo-ohms
resistor are recommended. And for specific
design, please refer to application information of
the primacy flyback controller.
Fast Charge
Recharge
5V
VCC
BATT+0.5V
0V
VBATT
CC charge
detection
Trickle
charge
detection
3.0V
2.0V
IBATT
CV charge
detection
Battery regulation
voltage
Ichg
10%Ichg
10%Ichg
1mA
0A
LED-R
ON
OFF
ON
LED-G
OFF
ON
OFF
Figure 3— Typical Charge Profile
MP26075 Rev. 1.01
www.MonolithicPower.com
5/23/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
10
MP26075 – HIGH EFFICIENCY CRADLE CHARGER
Start
Adapter OK?
VIN_UVLO<VIN<VIN_OVP
NO
Fault Indication
Charger off
YES
Battery OK?
NTC connection
NO
YES
Charge On,
LED-R on &
LED-G off
Normal Operation
Charge Mode?
V BAT>=V BAT_CV
CV-charge
VIN=BATT+0.5V
NO
V BAT_TC=<VBAT <V BAT_CC
V BAT_CC=<VBAT <V BAT_CV
CC-charge
VIN=BATT+0.5V
YES
ICHG<IBF
Battery Full ?
VBAT>=VBAT_CV?
V BAT<VBAT_TC
Pre -Charge
VIN=5V
TC-Charge
VIN=5V
NO
YES
YES
VBAT>=VBAT_CC?
VBAT>=VBAT_TC
?
NO
YES
Timer Out?
Finish charging
LED-R off& LED-G on
VIN=5V
NO
NO
YES
YES
NO
Timer Out?
NO
YES
VBAT<VBAT_RECHG?
Fault Protection
Any Protection
?
NO
YES
NO
NO
NTC Fault?
YES
YES
Charge Suspend
NTC OK?
NO
Thermal
Protection
Fold back charge
current
Whole charge
Timer Out?
YES
Charge Termination
Float LED-R and
LED-G
NO
YES
Charger Recovery
Figure 4— Normal Charge Operation and Fault Protection Flow Chart
MP26075 Rev. 1.01
www.MonolithicPower.com
5/23/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
11
MP26075 – HIGH EFFICIENCY CRADLE CHARGER
PACKAGE INFORMATION
QFN10 (3 X 3 mm)
2.90
3.10
0.30
0.50
PIN 1 ID
MARKING
0.18
0.30
2.90
3.10
PIN 1 ID
INDEX AREA
1.45
1.75
PIN 1 ID
SEE DETAIL A
10
1
2.25
2.55
0.50
BSC
5
6
TOP VIEW
BOTTOM VIEW
PIN 1 ID OPTION A
R0.20 TYP.
PIN 1 ID OPTION B
R0.20 TYP.
0.80
1.00
0.20 REF
0.00
0.05
SIDE VIEW
DETAIL A
NOTE:
2.90
0.70
1) ALL DIMENSIONS ARE IN MILLIMETERS.
2) EXPOSED PADDLE SIZE DOES NOT INCLUDE MOLD FLASH.
3) LEAD COPLANARITY SHALL BE 0.10 MILLIMETER MAX.
4) DRAWING CONFORMS TO JEDEC MO-229, VARIATION VEED-5.
5) DRAWING IS NOT TO SCALE.
1.70
0.25
2.50
0.50
RECOMMENDED LAND PATTERN
NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third
party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not
assume any legal responsibility for any said applications.
MP26075 Rev. 1.01
www.MonolithicPower.com
5/23/2011
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
12