MPS MP2626GR Usb-compliant single cell li-ion switching charger with usb-otg boost Datasheet

MP2626
USB-Compliant Single Cell Li-ion
Switching Charger with USB-OTG Boost
The Future of Analog IC Technology
DESCRIPTION
FEATURES
The MP2626 is a highly-integrated, flexible,
switch-mode battery charger with system power
management, designed for single-cell Li-ion
and Li-Polymer batteries used in a wide range
of portable applications.
•
•
•
The MP2626 can operate in both charge mode
and boost mode to allow full system and battery
power management. It is also able to work as a
boost regulator to power a USB peripheral from
the battery.
The MP2626 automatically detects the battery
voltage and charges the battery in the three
phases: trickle current charge, constant current
charge and constant voltage charge. Other
features include charge termination and autorecharge. This IC also integrates both inputcurrent limit and input-voltage regulation in
order to ensure USB compliant and minimize
the charging time.
The MP2626 can operate as a boost regulator
by setting the MODE pin to a HIGH logic. The
boost regulator includes output current limit and
short circuit protection. As long as MODE pin is
high, the MP2626 will discharge the battery in
the boost mode.
To guarantee safe operation, the MP2626 limits
the die temperature to a preset value of 120oC.
Other safety features include input over-voltage
protection, battery over-voltage protection,
thermal
shutdown,
battery
temperature
monitoring, and a programmable timer to
prevent prolonged charging of a dead battery.
MP2626 Rev. 1.0
2/28/2015
•
•
•
•
•
•
•
•
•
•
•
20V Absolute Maximum Input Voltage
6V Maximum Input Operating Voltage
Selectable 4.2V/ 4.35V Charge Voltage with
0.5% Accuracy at 25ºC
Power Management Function
Integrated Input-Current Limit and InputVoltage Regulation
Up to 2A Programmable Charge Current
Trickle-Charge Function
Negative Temperature Coefficient Pin for
Battery Temperature Monitoring
Programmable Timer Back-Up Protection
Thermal Regulation and Thermal Shutdown
Internal Battery Reverse Leakage Blocking
Reverse Boost Operation Mode for USB
Peripheral
Up to 91% 5V Boost Mode Efficiency @ 1A
Programmable Output Current Limit for
Boost Mode
Integrated Short Circuit Protection for Boost
Mode
APPLICATIONS
•
•
Sub-Battery Application
Power-Bank Applications for Smart-Phone
Tablet and other Portable Device
All MPS parts are lead-free and adhere to the RoHS directive. For MPS green
status, please visit MPS website under Products, Quality Assurance page.
“MPS” and “The Future of Analog IC Technology” are registered trademarks of
Monolithic Power Systems, Inc.
www.MonolithicPower.com
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© 2015 MPS. All Rights Reserved.
1
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
TYPICAL APPLICATION
R1
R2
FB
5V Input
ROLIM
C2
PMID
OLIM
SW
VIN
L1
RS1
ICHG
IBATT
R3
CIN C1
R5
C3
CSP
REG
BATT
R6
NTC
Battery Voltage GND: 4.35V
Programmable Pin High/Float: 4.2V
VB
CHG
VCC
C4
Battery
VPMID
PWIN
R4
CBATT
VBATT
ACOK
FREQ
BOOST
EN
VCC
ISET
MODE
ILIM
AGND
PGND
TMR
RILIM
CTMR
RISET
Table 1: Operation Mode
MODE
Low
High
EN
High
Low
X
__________
ACOK
Low
High
Operating Mode
Charge Mode, Enable Charging
Sleep Mode
Boost Mode
X=Don’t Care.
MP2626 Rev. 1.0
2/28/2015
www.MonolithicPower.com
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© 2015 MPS. All Rights Reserved.
2
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
ORDERING INFORMATION
Part Number*
MP2626GR
Package
QFN-24 (4mm×4mm)
Top Marking
See Below
*For Tape & Reel, add suffix – Z (e.g. MP2626GR-Z);
TOP MARKING
MPS: MPS prefix;
Y: year code;
WW: week code:
MP2626: product code of MP2626GR;
LLLLLL: lot number;
PACKAGE REFERENCE
TOP VIEW
MP2626 Rev. 1.0
2/28/2015
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3
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
ABSOLUTE MAXIMUM RATINGS (1)
Thermal Resistance
VIN ............................................... –0.3V to 20V
SW …………….. .................................................
–0.3V (-2V for <10ns) to 6.5V (8.5V for <20ns)
PMID, BATT ................................ –0.3V to 6.5V
QFN-24 (4mm×4mm) ............. 42 ....... 9 .... °C/W
-----------------
-------------
---------------------
ACOK, CHG, BOOST .................. –0.3V to 6.5V
All Other Pins ............................... –0.3V to 6.5V
Junction Temperature .............................. 150°C
Lead Temperature ................................... 260°C
(2)
Continuous Power Dissipation (TA = +25°C)
..........................................................2.97W
Junction Temperature .............................. 150°C
Operating Temperature............. –20°C to +85°C
Recommended Operating Conditions
(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 PCB.
(3)
Supply Voltage VIN........................... 4.5V to 6V
Battery Voltage VOUT .................... 2.5V to 4.35V
Operating Junction Temp. (TJ).−40°C to +125°C
MP2626 Rev. 1.0
2/28/2015
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4
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
ELECTRICAL CHARACTERISTICS
VIN = 5.0V, TA = 25°C, unless otherwise noted.
Parameter
Symbol Condition
VIN to PMID NMOS ON
Resistance
High-side PMOS ON Resistance
Low-side NMOS ON Resistance
RIN to PMID
RH
RL
DS
DS
High-Side PMOS Peak Current
Limit
IPEAK_HS
Low-Side NMOS Peak Current
Limit
IPEAK_LS
Switching Frequency
VCC UVLO
VCC UVLO Hysteresis
PWIN, Lower Threshold
Lower Threshold Hysteresis
PWIN, Upper Threshold
Min
FREQ = 0
FREQ = Float/ High
fSW
VCC
CC Charge Mode/Boost
Mode
TC Charge Mode
2
UVLO
VPWIN
L
0.75
VPWIN
H
1.1
Upper Threshold Hysteresis
Charge Mode
Input Quiescent Current
Typ
Max
100
mΩ
72
70
mΩ
mΩ
4.5
A
1.5
A
4.5
A
600
1200
2.2
100
0.8
50
1.15
kHz
2.4
0.85
1.2
50
IIN
Units
EN = 5V, Battery Float
EN = 0
RlLIM = 90.9kΩ
RlLIM = 49.9kΩ
400
720
450
810
RlLIM = 20kΩ
1800
V
mV
V
mV
V
mV
2.5
1.5
500
900
mA
mA
Input Current Limit
IIN_LIMIT
Input Over-Current Threshold
Input Over-Current Blanking
(5)
Time
Input Over-Current Recovery
(5)
Time
IIN(OCP)
2000
3
τINOCBLK
120
µs
τINRECVR
100
ms
Terminal Battery Voltage
Recharge Threshold
VBATT_FULL
VRECH
Leave VB floating or
connect to logic HIGH
Connect VB to GND
Leave VB floating or
connect to logic HIGH
Connect to VB to GND
Constant Charge (CC) Current
ICC
Trickle-Charge Current
ITC
MP2626 Rev. 1.0
2/28/2015
2200
A
4.179
4.200
4.221
4.328
4.350
4.372
3.950
4.015
4.080
4.091
4.157
250
103.3%
1000
4.223
1500
250
1650
Recharge Threshold Hysteresis
Battery Over Voltage Threshold
RS1=40mΩ, RISET = 69.8kΩ
900
RS1=40mΩ, RISET = 46.4kΩ
1350
mA
V
V
mV
VBATT
1100
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FULL
mA
mA
5
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
ELECTRICAL CHARACTERISTICS (continued)
VIN = 5.0V, TA = 25°C, unless otherwise noted.
Parameter
Symbol
Condition
Trickle-Charge Voltage
Threshold
VBATT_TC
Leave VB floating or connect
to high logic
Connect to VB to GND
Trickle-Charge Hysteresis
Termination Charge Current
Input-Voltage-Regulation
Reference
Boost Mode
IBF
RS1=40mΩ, RISET=69.8kΩ
VREG
Min
Typ
Max
Units
2.860
2.960
3.060
2.970
3.170
2.5%
3.070
200
10%
17.5%
mV
ICC
1.18
1.2
1.22
V
6
V
V
IN Voltage Range
4.2
Feedback Voltage
Feedback Input Current
Boost Over-Voltage Protection
Threshold
Boost Over-Voltage Protection
Threshold Hysteresis
Boost Quiescent Current
Programmable Boost Output
Current Limit Accuracy
1.18
1.2
1.22
200
V
nA
5.8
6
6.2
V
VIN(OVP)
VFB=1V
Threshold to turn off the
converter during boost mode
VIN falling from VIN(OVP)
125
IIN = 0A, MODE = 5V
IOLIM
RS1 = 40mΩ, ROLIM = 100kΩ
RS1 = 50mΩ, ROLIM=49.9kΩ
Programmable Boost Output
(5)
Current
VBATT = 4.2V
0.896
1.120
mV
2.0
mA
1.344
A
1.52
A
Boost Over-Current Blanking
(5)
Time
Boost Over-Current Recovery
(5)
Time
τOUTOCBLK
120
µs
τOUTRECVR
1
ms
Weak-Battery Threshold
VBATT(LOW)
During Boost mode
Before Boost mode
2.5
2.9
3.05
V
V
VBATT = 4.2V, VIN= 0V, MODE
= 0V
15
30
μA
400
mV
1
μA
Sleep Mode
Battery Leakage Current
ILEAKAGE
Indication and Logic
----------------
------------
-------------------
ACOK, CHG, BOOST pin
output low voltage
----------------
------------
Sinking 1.5mA
-------------------
ACOK, CHG, BOOST pin
leakage current
NTC and Time-Out Fault
(5)
Blinking Frequency
EN Input Logic LOW Voltage
EN Input High Voltage
Mode Input Logic LOW Voltage
Mode Input Logic HIGH Voltage
MP2626 Rev. 1.0
2/28/2015
Connected to 5V
fBLK
CTMR=0.1μF, ICHG=1A
13.7
Hz
0.4
V
0.4
V
V
V
1.4
1.4
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6
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
ELECTRICAL CHARACTERISTICS (continued)
VIN = 5.0V, TA = 25°C, unless otherwise noted.
Parameter
Protection
Symbol
Trickle-Charge Time
Total Charge Time
NTC Low Temp, Rising
Threshold
NTC Low Temp, Rising
Threshold Hysteresis
NTC High Temp, Rising
Threshold
NTC High Temp, Rising
Threshold Hysteresis
Charging Current Fold-back
(5)
Threshold
(5)
Thermal Shutdown Threshold
Condition
Min
CTMR=0.1µF, remains in TC
mode, ITC= 0.25A
CTMR=0.1µF, ICHG= 1A
65.3%
Typ
Max
Units
16.6
Min
400
Min
66.3%
67.3%
RNTC=NCP18XH103(0°C)
1%
VPMID
34%
35%
36%
RNTC=NCP18XH103(50°C)
1%
Charge Mode
120
°C
150
°C
Notes:
5) Guaranteed by design.
MP2626 Rev. 1.0
2/28/2015
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7
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
TYPICAL CHARACTERISTICS
CIN=CBATT=CPMID=C3=22µF, C1=C2=1µF, L1=4.7µH, RS1=50mΩ, C4=CTMR=0.1µF, Battery Simulator,
unless otherwise noted.
Sleep_Mode_Battery Current
vs. Temperature
70
VIN_OVP vs. Temperature
1.26
VOUTPUT_CURRENT_LIMIT(A)
5.97
VIN_OVP_R(V)
60
50
40
30
20
5.96
5.95
5.94
10
0
-50
0
50
5.93
-50
100
BATT_full VBH
vs. Temperature
4.30
0
50
100
4.40
BATT_full VBL = 4.35V
1.18
1.16
-50
4.10
4.00
4.30
4.25
4.20
4.15
4.10
4.05
4.00
3.90
3.90
-50
50
100
103.4
103.4
103.3
103.3
103.2
3.95
100
0
103.5
BATTOVP_VBH (%)
VBATT_VBL(V)
VBATT_VBH(V)
4.20
50
1.20
BATTOVP_VBH_%
vs. Temperature
4.35
0
1.22
Batt_full VBL
vs. Temperature
BATT_full VBH = 4.2V
3.80
-50
1.24
0
50
100
103.2
-50
0
50
100
BATTOVP_VBL_%
vs. Temperature
BATTOVP_VBL (%)
103.5
103.4
103.4
103.3
103.3
103.2
103.2
-50
MP2626 Rev. 1.0
2/28/2015
0
50
100
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8
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
TYPICAL PERFORMANCE CHARACTERISTICS
VIN=5V, CIN=CBATT=CPMID=C3=22µF, C1=C2=1µF, L1=4.7µH, RS1=50mΩ, C4=CTMR=0.1µF, Battery
Simulator, unless otherwise noted.
MP2626 Rev. 1.0
2/28/2015
www.MonolithicPower.com
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9
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN=5V, CIN=CBATT=CPMID=C3=22µF, C1=C2=1µF, L1=4.7µH, RS1=50mΩ, C4=CTMR=0.1µF, Battery
Simulator, unless otherwise noted.
MP2626 Rev. 1.0
2/28/2015
www.MonolithicPower.com
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© 2015 MPS. All Rights Reserved.
10
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN=5V, CIN=CBATT=CPMID=C3=22µF, C1=C2=1µF, L1=4.7µH, RS1=50mΩ, C4=CTMR=0.1µF, Battery
Simulator, unless otherwise noted.
Power On, Charge Mode
Power Off, Charge Mode
EN On, Charge Mode
VBATT_FULL=4.2V, VBATT=3.7V,
ICHG=2A
VBATT_FULL=4.2V, VBATT=3.7V,
ICHG=2A
VBATT_FULL=4.2V, VBATT=3.7V,
ICHG=2A
VBATT
1V/div.
VBATT
1V/div.
VPMID
2V/div.
VIN
1V/div.
IL
1A/div.
VPMID
2V/div.
VIN
1V/div.
IL
1A/div.
VEN
5V/div.
VSW
2V/div.
VBATT
1V/div.
IL
1A/div.
En Off, Charge Mode
Input Current Limit
Input Voltage Clamp
VBATT_FULL=4.2V, VBATT=3.7V，
ICHG=2A
VBATT_FULL=4.2V, VBATT=3.7V
VBATT_FULL=4.2V, VBATT=3.7V
VIN
1V/div.
VIN
1V/div.
VEN
5V/div.
VBATT
1V/div.
VSW
2V/div.
VBATT
1V/div.
IL
1A/div.
IIN
1A/div.
IPMID
2A/div.
IPMID
1A/div.
ICHG
2A/div.
ICHG
2A/div.
IN_PMID_Rdson
vs. Temperature
HS_Rdson
vs. Temperature
140.0
LS_Rdson
vs. Temperature
100.0
100.0
120.0
80.0
80.0
100.0
60.0
60.0
80.0
60.0
-50
MP2626 Rev. 1.0
2/28/2015
40.0
0
50
100
40.0
-50
0
50
100
20.0
-50
0
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50
100
11
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN=5V, CIN=CBATT=CPMID=C3=22µF, C1=C2=1µF, L1=4.7µH, RS1=50mΩ, C4=CTMR=0.1µF, Battery
Simulator, unless otherwise noted.
VBATT
1V/div.
VSW
2V/div.
VIN
1V/div.
VBATT
1V/div.
VSW
2V/div.
VIN
1V/div.
VBATT
1V/div.
VSW
2V/div.
VIN
1V/div.
IL
500mA/div.
IL
500mA/div.
IL
500mA/div.
VMODE
5V/div.
VMODE
5V/div.
VSW
2V/div.
VIN
1V/div.
IL
500mA/div.
VSW
2V/div.
VIN
1V/div.
IL
500mA/div.
VBATT
1V/div.
VSW
2V/div.
VIN
1V/div.
IIN
500mA/div.
VMODE
5V/div.
VMODE
5V/div.
VSW
2V/div.
VIN
1V/div.
VSW
2V/div.
VIN
1V/div.
IIN
500mA/div.
IIN
500mA/div.
MP2626 Rev. 1.0
2/28/2015
VBATT
2V/div.
VIN
1V/div.
IIN
500mA/div.
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12
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN=5V, CIN=CBATT=CPMID=C3=22µF, C1=C2=1µF, L1=4.7µH, RS1=50mΩ, C4=CTMR=0.1µF, Battery
Simulator, unless otherwise noted.
VBATT
1V/div.
VSW
2V/div.
VBATT
1V/div.
VBATT
1V/div.
VSW
2V/div.
VSW
2V/div.
VIN
1V/div.
VIN
1V/div.
VIN
1V/div.
IL
2A/div.
IL
2A/div.
IL
2A/div.
VIN/AC
500mV/div.
VBATT
1V/div.
VIN/AC
500mV/div.
IIN
1A/div.
IIN
1A/div.
VIN
1V/div.
VBATT
1V/div.
VBOOST
2V/div.
IL
2A/div.
VIN/AC
200mV/div.
VBATT
1V/div.
IIN
500mA/div.
VBATT
1V/div.
100
6
95
5
90
4
85
3
80
2
75
1
70
0
0
MP2626 Rev. 1.0
2/28/2015
0.3
0.6
0.9
1.2
1.5
0
0.5
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1
1.5
13
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
PIN FUNCTIONS
Pin #
Name
1
FREQ
2
VIN
3
VCC
4
ILIM
5
PWIN
6
TMR
7
REG
8
ACOK
9
FB
10
NTC
23
MODE
24
EN
----------------
Description
Connect to GND to program the operating frequency to 600kHz. Leave floating or connect to
HIGH to program the operating frequency to 1.2MHz.
Adapter Input. Place a bypass capacitor close to this pin to prevent large input voltage spikes.
Internal Circuit Power Supply. Bypass to GND with a 100nF ceramic capacitor. This pin
CANNOT carry any load.
Input Current Set. Connect to GND with an external resistor to program input current limit in
charge mode.
Input pin to detect the presence of valid input power. Pulling this pin to GND will turn off the INto-PMID pass through MOSFET.
Oscillator Period Timer. Connect a timing capacitor between this pin and GND to set the
oscillator period. Short to GND to disable the Timer function.
Input Voltage Feedback for input voltage regulation loop. Connect to tap of an external resistor
divider from VIN to GND to program the input voltage regulation. Once the voltage at REG pin
drops to the inner threshold, the charge current is reduced to maintain the input voltage at the
regulation value.
Valid Input Supply Indicator. Logic LOW on this pin indicates the presence of a valid power
supply.
Boost Output Voltage Feedback.
Negative Temperature Coefficient (NTC) Thermistor.
Programmable Charge Current Pin. Connect an external resistor to GND to program the
11
ISET
charge current.
Programmable Output-Current Limit for boost mode. Connect an external resistor to GND to
12
OLIM
program the system current in boost mode.
13
AGND Analog Ground
Programmable Battery-Full Voltage. Leave floating or connect to logic HIGH for 4.2V, while
14
VB
Connect to GND for 3.6V.
15
BATT Positive Battery Terminal / Battery Charge Current Sense Negative Input.
16
CSP
Battery Charge Current Sense, Positive Input.
------------------Boost Mode Indicator. Logic LOW indicates boost mode in operation. This is an open drain pin
17
BOOST during charge mode or sleep mode.
-----------Charge Completion indicator. Logic LOW indicates charge mode. This is an open drain pin
18
CHG during charge complete or suspended.
PGND,
19
Exposed Power Ground. Connect the exposed pad and GND pin to the same ground plane.
Pad
20
SW
Switch Output Node. It is recommended not to place vias on the SW plane during PCB layout.
Connect Point of Blocking Switch and High-side switch. A minimum of 22μF ceramic cap is
21, 22
PMID
required to be placed as close as possible to the PMID and GND pins.
MP2626 Rev. 1.0
2/28/2015
Mode Select. Logic HIGH→boost mode. Logic LOW→charge mode.
Charge Control Input. Logic HIGH enables charging. Logic LOW disables charging. Active only
__________
when ACOK is low (input power is OK)
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14
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
BLOCK DIAGRAM
PMID
FB
Q1
VIN
SW
HSMOS
Buffer
LSMOS
A1
VCC
Current
Sense
Driver
VBATT
K1*ICHG
CSP
BATT
PWM Signal
Charge
Pump
PGND
ACOK
VBATT
PWIN
FREQ
0.8V
Mode Control
1.15V
VCC
PWM Controller
VSYS
Control Logic&
Mode Selection
BATT+
300mV
SYS
NTC
TRef
MODE
TJ
EN
VB
GMT
VBATT_Ref
Thermal
Shutdown
VBATT
REG
GMINV
VREG_Ref
ISET
MIN
GMI
ICHG_Ref
ACOK
GMV
CHG
Indication&
Timer
BOOST
K1*ICHG
ILIM
IIN_Ref
Current Setting
GMINI
K2*IIN
TMR
AGND
Figure 1: Functional Block Diagram in Charge Mode
MP2626 Rev. 1.0
2/28/2015
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15
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
PMID
FB
SW
HSMOS
Q1
VIN
A1
VCC
CSP
LSMOS
Driver
VBATT
Charge
Pump
BATT
PWM Signal
Integration
PGND
A2
ACOK
To Current
Setting
VBATT
PWIN
FREQ
0.8V
Mode Control
1.15V
VCC
PWM Controller
Control Logic&
Mode Selection
BATT+
300mV
NTC
MODE
EN
VB
VRef
Thermal
Shutdown
VFB
ACOK
GMV
REG
CHG
Indication&
Timer
BOOST
IOLIM_Ref
Current Setting
OLIM
GMINI
K3*ISYS
TMR
AGND
Figure 2: Functional Block Diagram in Boost Mode
MP2626 Rev. 1.0
2/28/2015
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16
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
OPERATION FLOW CHART
POR
MODE High
NO
ACOK
YES
Boost Mode
/BOOST Low
YES
NO
Charge Mode
/CHG Low
Sleep Mode
Figure 3: Mode Selection Flow Chart
MP2626 Rev. 1.0
2/28/2015
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17
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
OPERATION FLOW CHART (continued)
Figure 4: Normal Operation and Fault Protection in Charge Mode
MP2626 Rev. 1.0
2/28/2015
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18
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
OPERATION FLOW CHART (continued)
Power Path Management
No
VPWIN touch the VREG?
No
IIN hit the IIN_LIMIT?
Yes
Yes
Charge Current
Decrease
ICHG ≤0?
No
Yes
IIN >7A?
Normal Operation
No
IIN exceeds IIN(OCP)?
No
Yes
Regulate the IIN at
IIN(OCP)
No
Yes
TINOCBLK reaches?
Yes
Yes
IN to PMID MOSFET
turns Off
No
TINRECVR reaches?
Figure 5: Power-Path Management in Charge Mode
MP2626 Rev. 1.0
2/28/2015
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19
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
OPERATION FLOW CHART (continued)
Boost Mode
/BOOST Low
Normal Boost
Operation
No
No
IIN > IOLIM?
VBATT >2.9V?
Yes
Yes
Output current loop
works, VSYS decreases
No
No
Mode High?
VIN < VBATT?
Yes
Yes
Normal Boost
Operation
VIN < 2V?
No
VBATT<2.5V?
Yes
Boost Turns Off
No
No
Yes
Yes
Down mode
IL hits the
current limit
TSYSBLK Reaches?
Yes
Yes
Boost Shutdown
No
TSYSRECVR
Reaches?
Figure 6: Operation Flow Chart in Boost Mode
MP2626 Rev. 1.0
2/28/2015
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20
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
START UP TIME FLOW IN CHARGE MODE
Condition: EN = 5V, Mode = 0V, /ACOK and /CHG are always pulled up to an external constant 5V
VIN
VPWIN > 0.8V
&
VIN > VBATT+ 300mV
0V
5V
EN 0V
Mode
0V
VCC
VCC follows VIN
2.2V
Band
Gap 0V
5V
ACOK 0V
VPMID > VBATT + 50mV
VPMID
5V
CHG
0V
400μs
400μs
SS
150μs
150μs
Force
Charge
ICC
Charge 0A
Current
10%ICC
IBF
Comparator
Battery
Voltage
VBATT_FULL
Auto‐recharge threshold
Assume vBATT > VBATT_TC
Autorecharge
Figure 7: Input Power Start-Up Time Flow in Charge Mode
MP2626 Rev. 1.0
2/28/2015
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21
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
START UP TIME FLOW IN CHARGE MODE
Condition: VIN = 5V, Mode = 0V, /ACOK and /CHG are always pulled up to an external constant 5V.
Figure 8: EN Start-Up Time Flow in Charge Mode
MP2626 Rev. 1.0
2/28/2015
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22
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
START UP TIME FLOW IN BOOST MODE
Condition: VIN_SET = 5V, Mode = 5V, /Boost is always pulled up to an external constant 5V.
Figure 9: Battery Power Start-Up Time Flow in Boost Mode
MP2626 Rev. 1.0
2/28/2015
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23
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
START UP TIME FLOW IN BOOST MODE
Condition: VIN_SET = 5V, /Boost is always pulled up to an external constant 5V.
Figure 10: Mode Start-Up Time Flow in Boost Mode
MP2626 Rev. 1.0
2/28/2015
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24
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
OPERATION
INTRODUCTION
Auto-Recharge
The MP2626 is a highly-integrated, flexible,
switch-mode battery charger with bi-directional
operation for a boost function that can step-up
the battery voltage to power the USB peripheral.
Depending on the status of MODE and VIN, it
operates in three different modes: charge mode,
boost mode and sleep mode.
Once the battery charge cycle is completed, the
charger remains off. During this time, the system
load may consume battery power, or the battery
may self discharge. To ensure the battery will not
go into depletion, a new charge cycle
automatically begins when the battery voltage
falls below the auto-recharge threshold and the
input power is present. The timer is reset when
the auto-recharge cycle begins.
In charge mode, the MP2626 can work with a
single cell Li-ion or Li-polymer battery. In boost
mode, MP2626 boosts the battery voltage to VIN
to power higher-voltage systems. In sleep mode,
both charging and boosting operations are
disabled and the device enters a power saving
mode to help reduce the overall power
consumption. The MP2626 monitors MODE and
VIN to allow smooth transition between different
modes of operation.
CHARGE MODE OPERATION
Charge Cycle (TC ChargeÆCC ChargeÆCV
Charge)
In charge mode, the MP2626 has five control
loops to regulate the input current, input voltage,
charge current, charge voltage, and device
junction temperature. The MP2626 charges the
battery in three phases: trickle current (TC),
constant current (CC), and constant voltage (CV).
While charging operation is enabled, all five
loops are active but only one determines the IC
behavior. A typical battery charge profile is
depicted in Figure 11(a). The charger stays in TC
charge mode until the battery voltage reaches a
TC-to-CC threshold. Otherwise the charger
enters CC charge mode. When the battery
voltage rises to the CV-mode threshold, the
charger operates in constant voltage mode.
Figure 11 (b) shows a typical charge profile when
the input-current-limit loop dominates during the
CC charge mode. And in this case the charger
maximizes the charging current due to the
switching-mode charger solution, resulting in
faster charging than a traditional linear solution.
MP2626 Rev. 1.0
2/28/2015
During the off state after the battery is fully
charged, if the input power re-starts or the EN
signal refreshes, the charge cycle will start and
the timer will reset no matter what the battery
voltage is.
CC>>>CV
Threshold
ICHG
Constant
Charge
Current
VBAT
TC>>>CC
Threshold
Trickle
Charge
Current
Trickle charge
CC charge
CV charge
Charge Full
(a) Without input current limit
Constant
Charge
Current
CC>>>CV
Threshold
ICHG
Input
Current
Limit
VBAT
TC>>>CC
Threshold
Trickle
Charge
Current
Trickle charge
CC charge
CV charge
Charge Full
(b) With input current limit
Figure 11: Typical Battery Charging Profile
Battery Over-Voltage Protection
The MP2626 has battery over-voltage protection.
If the battery voltage exceeds the battery overvoltage threshold (103.3% of the battery-full
voltage), charging is disabled. Under this
condition, an internal current source draws a
current from the BATT pin to decrease the
battery voltage and protect the battery.
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25
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
Timer Operation in Charge Mode
The MP2626 uses an internal timer to terminate
the charging. The timer remains active during the
charging process. An external capacitor between
TMR and GND programs the charge cycle
duration.
If charging remains in TC mode beyond the
trickle-charge time τTOTAL_TMR, charging will
terminate. The following equation determines the
length of the trickle-charge period:
4.5 × 10 4 × 1.6( V ) × C TMR (μF)
(１)
0.52 × ITC ( A ) × RS1(mΩ) + 2(μA )
The maximum total charge time is:
τ TRICKLE_ TMR =
Input Voltage Regulation in Charge Mode
In charge mode, if the input power source is not
sufficient to support both the charge current and
system load current, the input voltage will
decrease. As the input voltage approaches the
programmed input voltage regulation value,
charge current is reduced to allow priority of
system power and maintain proper regulation of
the input voltage.
The input voltage can be regulated by a resistor
divider from IN pin to REG pin to AGND
according to the following equation:
VREG = VIN_ R ×
R6
R6 + R5
(4)
3.4 × 106 × 1.6( V ) × CTMR (μF)
(2)
0.52 × ITC ( A ) × RS1(mΩ) + 2(μA )
where the VREG is the internal voltage reference,
1.2V, and the VIN_R is the desired regulation
voltage.
Negative Temperature Coefficient (NTC) Input
for Battery Temperature Monitoring
Input Over-Current Protection and Over
Voltage Protection for Pass-through Path
The MP2626 has a built-in NTC resistance
window comparator, which allows the MP2626 to
monitor the battery temperature via the batteryintegrated thermistor. Connect an appropriate
resistor from VPMID to the NTC pin and connect
the thermistor from the NTC pin to GND. The
resistor divider determines the NTC voltage
depending on the battery temperature. If the NTC
voltage falls out of the NTC window, the MP2626
stops charging. The charger will then restart if the
temperature goes back into NTC window range.
Please refer to Application Information section for
the appropriate resistance selection.
The MP2626 has an integrated IN to PMID passthrough path to allow direct connection of the
input voltage to the system even if charging is
disabled. Based on the above, the MP2626
continuously monitors both input current and
voltage. In the event of an OCP or OVP, charge
current will be reduced to ensure priority of the
system power requirements.
Input-Current Limiting in Charge Mode
When the total input current exceeds 3A, Q2 (Fig
12) is controlled linearly to regulate the current. If
the current continuous to exceed 3A after a
120µs blanking time, Q2 will be turned off. In the
event of input current exceeding 7A, Q2 will be
turned off almost instantaneously and without
any blanking time, this to protect both Q1 and Q2.
τTRICKLE_ TMR =
The MP2626 has a dedicated pin used to
program the input current limit. The current at
ILIM is a fraction of the input current; the voltage
at ILIM indicates the average input current of the
switching regulator as determined by the resistor
value between ILIM and GND. As the input
current approaches the programmed input
current limit, charge current is reduced to allow
priority to system power.
In addition, the MP2626 also features input over
current and voltage protection for the IN to PMID
pass-through path.
Input over-current protection (OCP)
Use the following equation to determine the input
current limit threshold,
IILIM =
MP2626 Rev. 1.0
2/28/2015
40.5(kΩ)
(A)
RILIM (kΩ)
(3)
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26
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
Input over-voltage protection (OVP)
The MP2626 uses the PWIN pin to sense the
status of input voltage. When the voltage at the
PWIN pin is lower than 0.8V or higher than 1.15V,
an invalid input power source is detected by the
MP2626. At this time the IN to PMID passthrough path will be turned off. An OVP threshold
can be programmed via PWIN pin to prevent an
over voltage event happening at PMID side when
plugging in a wrong adapter.
voltage drops below the TC threshold. Moreover,
the switching frequency also decreases when the
BATT voltage drops to 40% of the charge-full
voltage.
Thermal Foldback Function
The MP2626 implements thermal protection to
prevent thermal damage to the IC and the
surrounding components. An internal thermal
sense and feedback loop automatically
decreases the programmed charge current when
the die temperature reaches 120°C. This function
is called the charge-current-thermal foldback. Not
only does this function protect against thermal
damage, it can also set the charge current based
on requirements rather than worst-case
conditions while ensuring safe operation.
Furthermore, the part includes thermal shutdown
protection where the ceases charging if the
junction temperature rises to 150°C.
Non-sync Operation Mode
Figure12: Integrated Pass-through Path
Charge Current Setting
The external sense resistors, RS1 and RISET,
program the battery charge current, ICHG. Select
RISET based on RS1:
2800
(5)
ICHG ( A ) =
RISET (kΩ) × RS1(mΩ)
Battery Short Protection
The MP2626 has two current limit thresholds. CC
and CV modes have a peak current limit
threshold of 4.5A, while TC mode has a current
limit threshold of 1.5A. Therefore, the current limit
threshold decreases to 1.5A when the battery
During charging mode, the MP2626 continuously
monitors the total input current flowing from IN
pin to PMID pin. When the input current is lower
than 170mA, the low side switch operates as a
non-synchronous MOSFET.
Fully Operation Indication
The MP2626 integrates indicators for the
following conditions as shown in Table 2.
When timer or NTC fault happens, charging will
terminate or be suspended and indication of
-----------CHG blinks in a frequency fBLK:
fBLK =
2(μA )
1.46( V ) × CTMR (μF)
(6)
Table 2: Indicator for Each Operation Mode
----------------
Operation
ACOK
Charging
Charge Mode
End of Charge, charging disabled
------------
CHG
-------------------
BOOST
Low
Low
High
High
Blinking
NTC Fault, Timer Out
Boost Mode
High
High
Low
Sleep Mode, VCC absent
High
High
High
MP2626 Rev. 1.0
2/28/2015
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27
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
BOOST MODE OPERATION
Low-Voltage Start-Up
The minimum battery voltage required to start up
the circuit in boost mode is 2.9V. Initially, when
VPMID < VBATT, the MP2626 works in down mode.
In this mode, the synchronous P-MOSFET stops
switching and its gate connects to VBATT statically.
The P_MOSFET keeps off as long as the voltage
across the parasitic CDS (VSW) is lower than VBATT.
When the voltage across CDS exceeds VBATT, the
synchronous P-MOSFET enters a linear mode
allowing the inductor current to decrease and
flowing into the PMID pin. Once VPMID exceeds
VBATT, the P-MOSFET gate is released and
normal closed-loop PWM operation is initiated. In
boost mode, the battery voltage can drop to as
low as 2.5V without affecting circuit operation.
Output Disconnect and Inrush Limiting
The MP2626 allows for true output disconnect by
eliminating body diode conduction of the internal
P-MOSFET rectifier. VIN can go to 0V during
shutdown, drawing no current from the input
source. It also allows for inrush current limiting at
start-up, minimizing surge currents from the input
supply. To optimize the benefits of output
disconnect, avoid connecting an external
Schottky diode between the SW and PMID pins.
Board layout is extremely critical to minimize
voltage overshoot at the SW pin due to stray
inductance. Keep the output filter capacitor as
close as possible to the PMID pin and use very
low ESR/ESL ceramic capacitors tied to a good
ground plane.
Boost Output Voltage Setting
In boost mode, the MP2626 programs the output
voltage via the external resistor divider at FB pin,
and provides built-in output over-voltage
protection (OVP) to protect the device and other
components against damage when VIN goes
beyond 6V. Once the output over-voltage occurs,
the MP2626 turns off the boost converter. When
the voltage on VIN drops to a normal level, the
boost converter restarts again as long as the
MODE pin remains active.
MP2626 Rev. 1.0
2/28/2015
Boost Output-Current Limiting
The MP2626 integrates a programmable output
current limit function in boost mode. If the boost
output current exceeds this programmable limit,
the output current will be limited at this level and
the VIN voltage will start to drop down. The OLIM
pin programs the current limit threshold up to
1.5A as per the following equation:
2800
(7)
IOLIM ( A ) =
× 1.6
ROLIM(kΩ) × RS1((mΩ)
Boost Output Over-Current Protection
The MP2626 integrates three-phase output overcurrent protection.
Phase one (boost mode output current limit):
when the output current exceeds the
programmed output current limit, the output
constant current loop controls the output current,
the output current remains at its limit of IOLIM, and
VIN decreases.
Phase two (down mode): when VIN drops below
VBATT+100mV and the output current loop
remains in control, the boost converter enters
down mode and shutdown after a 120μs blanking
time.
Phase three (short circuit mode): when VIN
drops below 2V, the boost converter shuts down
immediately once the inductor current hits the
fold-back peak current limit of the low side NMOSFET. The boost converter can also recover
automatically after a 1ms deglitch period.
Thermal Shutdown Protection
Thermal shutdown protection is also active in
boost mode. Once the junction temperature rises
higher than 150°C, the MP2626 enters thermal
shutdown. It will not resume normal operation
until the junction temperature drops below 120°C.
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28
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
APPLICATION INFORMATION
COMPONENT SELECTION
Setting the Charge Current in Charge Mode
In charge mode, both the external sense resistor,
RS1, and the resistor RISET connect to the ISET
pin to set the charge current (ICHG) of the MP2626.
(see the Typical Application Circuit)
Given ICHG and RS1, RISET can be calculated as:
RISET (kΩ) =
2800
ICHG ( A ) × RS1((mΩ)
VIN − VPWIN
× R4
(12)
VPWIN
For a typical application, start with R4=5.1kΩ, R3
is 21.5kΩ.
R3 =
(8)
For example, for ICHG=2A, and RS1=50mΩ, thus:
RISET=28kΩ.
Setting the Input Voltage Regulation in
Charge Mode
In Charge mode, connect a resistor divider from
the VIN to GND with tapped to REG pin to
program the input voltage regulation.
VIN _ R = VREG ×
RILIM (kΩ ) =
40.5(kΩ ) × 1(A)
IIN _ LIM (A)
(9)
Where, RILIM must exceed 15kΩ so that IIN_LIM is
in the range of 0A to 2.7A.
For
most
applications,
use
RILIM=45kΩ
(IUSB_LIM=900mA) for USB3.0 mode, and use
RILIM=81kΩ (IUSB_LIM=500mA) for USB2.0 mode.
Setting the Input Voltage Range for Different
Operation Modes
A resistive voltage divider from the input to PWIN
pin determines the operation mode of MP2626.
VPWIN = VIN ×
R4
R4 + R3
(10)
When MP2626 works in the charge mode (see
Table1), the voltage on PWIN should be between
0.8V and 1.15V. For a wide operating range, use
a maximum input voltage of 6V as the upper
threshold for a voltage ratio of:
VPWIN 1.15
R4
=
=
VIN
6
R4 + R3
(11)
(13)
× R6(V)
(14)
With the given R6, R5 is:
Setting the input Current Limiting in Charge
Mode
In charge mode, connect a resistor from the ILIM
pin to AGND to program the input current limit.
The relationship between the input current limit
and setting resistor is as following:
R6 + R5
(V)
R6
R5 =
VIN _ R − VREG
VREG
For a preset input voltage regulation value, say
4.75V, start with R6=5.1kΩ, R5 is 15kΩ.
NTC Function in Charge Mode
Figure 13 shows that an internal resistor divider
sets the low temperature threshold (VTL) and high
temperature threshold (VTH) at 66.3%·VPMID and
35%·VPMID respectively. For a given NTC
thermistor, select an appropriate RT1 and RT2 to
set the NTC window.
R T 2 // R NTC _ Cold
VTL
=
= TL = 66.3% (15)
VSYS R T1 + R T 2 // R NTC _ Cold
R T 2 // RNTC _ Hot
VTH
=
= TH = 35% (16)
VSYS R T1 + R T 2 // RNTC _ Hot
Where RNTC_Hot is the value of the NTC resistor at
the upper bound of its operating temperature
range, and RNTC_Cold is its lower bound.
The two resistors, RT1 and RT2, independently
determine the upper and lower temperature limits.
This flexibility allows the MP2626 to operate with
most NTC resistors for different temperature
range requirements. Calculate RT1 and RT2 as
follows:
R T1 =
RNTC _ hot × RNTC _ Cold × (TL − TH)
TH × TL × (RNTC _ Cold − RNTC _ Hot )
(17)
With the given R4 and R3,
MP2626 Rev. 1.0
2/28/2015
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MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
RT2 =
RNTC_hot × RNTC _Cold × (TL − TH)
(1− TL) × TH× RNTC_ Cold − (1− TH) × TH× RNTC_Hot )
(18)
For example, the NCP18XH103 thermistor has
the following electrical characteristic:
At 0oC, RNTC_Cold=27.445kΩ;
At 50oC, RNTC_Hot=4.1601kΩ;
In the boost mode, connect a resistor form the
OLIM pin to AGND to program the output current
limit. The relationship between the output current
limit and setting resistor is as follows:
R OLIM (kΩ ) =
Base on equation (17) and equation (18),
RT1=6.65kΩ and RT2=24.9kΩ are suitable for an
NTC window between 0oC and 50oC
If no external NTC is available, connect RT1 and
RT2 to keep the voltage on the NTC pin within the
valid NTC window: e.g., RT1=RT2=10kΩ.
2800
× 1. 6
IOLIM ( A ) × RS1(m Ω )
(21)
The output current limit of the boost can be
programmed up to 1.5A (min). Considering 15%
output current limit accuracy, typical 1.79A output
current limit is required. According to the above
equation, given 50mΩ sense resistor, 49.9kΩ
ROLIM will get 1.79A output current limit.
Selecting the Inductor
Inductor selection trades off between cost, size,
and efficiency. A lower inductance value
corresponds with smaller size, but results in
higher ripple currents, higher magnetic hysteretic
losses, and higher output capacitances. However,
a higher inductance value benefits from lower
ripple current and smaller output filter capacitors,
but results in higher inductor DC resistance (DCR)
loss.
Figure 13: NTC Function Block
Choose an inductor that does not saturate under
the worst-case load condition.
For Convenience, an NTC thermistor design
spreadsheet is also provided, please inquire if
necessary.
1. In Charge Mode
When MP2626 works in charge mode (as a Buck
Converter), estimate the required inductance as:
Setting the Output Voltage in Boost Mode
In the boost mode, the output voltage on the VIN
pin can be regulated to the value customer
required between 4.2V and 6V by the resistor
divider at FB pin as R1 and R2 in the typical
application circuit.
VIN = 1.2V ×
R1 + R2
R2
(19)
Where, 1.2V is the voltage reference of boost
output voltage. With a typical value for R2, 10kΩ,
R1 can be determined by:
R1 =
VIN − 1.2V
× R2
1.2V
(20)
L=
VIN − VBATT VBATT
×
VIN × fS
ΔIL _ MAX
(22)
Where VIN, VBATT, and fSW are the typical input
voltage, the CC charge threshold, and the
switching frequency, respectively. ΔIL_MAX is the
maximum inductor ripple current, which is usually
designed at 30% of the CC charge current.
With a typical 5V input voltage, 30% inductor
current ripple at the corner point between trickle
charge and CC charge (VBATT=3V), the
inductance is 2.2μH (for a 1.2MHz switching
frequency) and 4.4μH (for a 600kHz switching
frequency).
For example, for a 5V output voltage, R2 is 10kΩ,
and R1 is 31.6kΩ.
Setting the Output Current Limit in Boost
Mode
MP2626 Rev. 1.0
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MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
2 In Boost Mode
When the MP2626 is in boost mode (as a Boost
Converter), the required inductance value is
calculated as:
V − VBATT
VIN
×
L = IN
ΔIL _ MAX
VBATT × fS
ΔIL _ MAX = (30% − 40%) × IBATT(MAX)
IBATT(MAX) =
VIN × IIN _ MAX
VBATT × η
(23)
(24)
(25)
Where VBATT is the minimum battery voltage, fSW
is the switching frequency, and ΔIL_MAX is the
peak-to-peak inductor ripple current, which is
approximately 30% of the maximum battery
current IBATT(MAX), IIN_MAX is the maximum output
current and η is the efficiency.
In the worst case where the battery voltage is 3V,
a 30% inductor current ripple, and a typical boost
output voltage (VIN=5V), the inductance is 2.0μH
(for a 1.2MHz switching frequency) and 4.0μH
(for a 600 kHz switching frequency) when the
efficiency is about 90% and IIN_MAX1.5A.
For Best results, use an inductor with an
inductance of 2.2μH (for a 1.2MHz switching
frequency) and 4.4μH (for a 600kHz switching
frequency) with a DC current rating that is at least
30% higher maximum charge current for
applications. For higher efficiency, minimize the
inductor’s DC resistance. For higher efficiency,
minimize the inductor’s DC resistance.
Selecting the Input Capacitor CIN
The input capacitor CIN reduces both the surge
current drawn from the input and the switching
noise from the device. The input capacitor
impedance at the switching frequency should be
less than the input source impedance to prevent
high frequency switching current from passing to
in the input. For best cases, use ceramic
capacitors with X7R dielectrics because of their
low ESR and small temperature coefficients. For
most applications, a 22μF capacitor will suffice.
The capacitor CPMID acts as the input capacitor of
the buck converter in the charge mode. The input
effective ripple current:
VTC × (VINMAX − VTC )
IRMS _ MAX = ICC _ MAX ×
VINMAX
(26)
2. Boost Mode
The capacitor, CPMID, is the output capacitor of
the boost converter. CPMID keeps the output
voltage ripple small and ensures feedback loop
stability. The output effective ripple current is
given by:
IRMS _ MAX = ICC _ MAX ×
VTC × (VINMAX − VTC )
VINMAX
(27)
Since the input voltage is passes to PMID directly,
VIN_MAX=VPMID_MAX, both charge mode and boost
mode have the same current ripple.
For ICC_MAX=1.5A, VTC=3V, VIN_MAX=6V, the
maximum effective ripple current is 0.75A, Select
the PMID capacitors base on the ripple-current
temperature rise not exceeding 10oC. For best
results, use ceramic capacitors with X7R
dielectrics with low ESR and small temperature
coefficients. For most applications, use one 22μF
capacitor.
Selecting the Battery Capacitor CBATT
CBATT is in parallel with the battery to absorb the
high-frequency switching ripple current.
1. Charge Mode
The capacitor CBATT is the output capacitor of the
buck converter. The output voltage ripple is then:
ΔrBATT =
ΔVBATT
1 − VBATT / VIN
=
VBATT
8 × CBATT × fS2 × L
(28)
2. Boost Mode
The capacitor CBATT is the input capacitor of the
boost converter. The input voltage ripple is the
Selecting the PMID Capacitor CPMID
Select CPMID based on the demand of the current
ripple.
1. Charge Mode
MP2626 Rev. 1.0
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MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
same as the output voltage ripple from equation
(28).
Both charge mode and boost mode have the
same battery voltage ripple. The capacitor CBATT
can be calculated as:
CBATT =
1 − VTC / VIN _ MAX
8 × ΔrBATT _ MAX × fS2 × L
(29)
To guarantee the ±0.5% BATT voltage accuracy,
the maximum BATT voltage ripple must not
exceed 0.5% (e.g. 0.2%). The worst case occurs
at the minimum battery voltage of the CC charge
with the maximum input voltage.
3) The PCB should have a ground plane
connected directly to the return of all components
through vias (e.g. two vias per capacitor for
power stage capacitors, one via per capacitor for
small-signal components). If possible, add vias
inside the exposed pads for the IC. A star ground
design approach is typically used to keep the
circuit block currents isolated (power-signal /
control-signal), which reduces noise-coupling and
ground-bounce issues. A single ground plane for
this design gives good results.
4) Place ISET, OLIM and ILIM resistors very
close to their respective IC pins.
EN
SW
PMID
PMID
PGND
MODE
For VINMAX=6V, VCC_MIN=VTC=3V, L=4.4μH,
fSW=600kHz or 1.2MHz, ΔrBATT_MAX=0.1%, CBATT is
8.9μF (for a 600kHz switching frequency) or
5.6μF (for a 1.2MHz switching frequency).
FREQ
VIN
CSP
BATT
VB
AGND
ISET
N TC
FB
R EG
OLIM
ACO K
A 22μF ceramic with X7R dielectrics capacitor
will suffice.
CHG
BOOST
VC C
ILIM
PWIN
TMR
PCB LAYOUT GUIDE
PCB layout is very important to meet specified
noise, efficiency and stability requirements. The
following design considerations can improve
circuit performance:
1) Route the power stage adjacent to their
grounds. Aim to minimize the high-side switching
node (SW, inductor) trace lengths in the highcurrent paths
Keep the switching node short and away from all
small control signals, especially the feedback
network.
Place the input capacitor as close as possible to
the VIN and PGND pins. The local power input
capacitors, connected from the PMID to GND,
must be placed as close as possible to the IC.
Place the output inductor close to the IC and
connect the output capacitor between the
inductor and PGND of the IC.
Figure 14: PCB Layout Guide
DESIGN EXAMPLE
Below is a design example following the
application guides for the specifications:
Table 3 Design Example
VIN
VOUT
fSW
5V
3.7V
1200KHz
Figure 15 shows the detailed application
schematic.
The
Typical
Performance
Characteristics section shows the typical
performance and circuit waveforms. For more
possible applications of this chip, please refer to
the related Evaluation Board datasheets.
2) For high-current applications, the power pads
for IN, SW, BATT and PGND should be
connected to as many copper planes on the
board as possible. The exposed pad should
connect to as many GND copper planes on the
board as possible, too. This improves thermal
performance because the board conducts heat
away from the IC.
MP2626 Rev. 1.0
2/28/2015
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32
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
TYPICAL APPLICATION CIRCUITS
SYS
R_Single
1
5
2
NTC
PWIN
JP2
JP3
3
VCC
1
24
23
4
ACOK
FREQ
EN
BOOST
MODE
ISET
ILIM
TMR
1
22uF
C6
NC
15
NTC
SYS
1
14
JP4
10K
13
3
RT1 10K
1
10K
18
1
8
LED1
1
VCC
R5
2
2
LED2
1
17
2
SYS
2
LED3
11
2K
R9
2K
R10
2K R11
LED
2
2JP5
6
CTMR
RISET
28K
VBATT
100nF
19
AGND
13
1
RILIM
15K 1%
CHG
VCC
AGND
JP1
VB
22uF
10
RT2
MP2626
CBATT
1
R8
10K
BATT
C3
3
2
R7
10K
CSP
REG
16
2
7
1
C4
100nF
R6
10K
2
15K
VCC
VCC
BATT
20
2
5.1K
SW
31
PGND
VIN
VBATT
50m
1
2
RS1
2
R5
2
L1
4.7uH
2
R6
SW 1
1
21.5K
U1
2
5.1K
PGND
49.9K
12
R3
FB
OLIM
1
2
R4
21,22
1
2
C1
1uF
CIN
22uF
2
C5
NC
PMID
1uF
1
VIN
CSYS
22uF
ROLM
NC
VIN
SYS
C7
22uF
1
C2
10K
2
PGND
31.6K
C8
1
9
NC
FB
R2
2
R1
FB
PMID
SYS
0
R_Dual
PMID
VIN
Figure 15: Detailed Application Circuit
MP2626 Rev. 1.0
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33
MP2626 – SINGLE CELL LI-ION SWITCHING CHARGER WITH USB OTG
PACKAGE INFORMATION
QFN-24 (4mmx4mm)
3.90
4.10
2.50
2.80
19
PIN 1 ID
MARKING
18
3.90
4.10
PIN 1 ID
INDEX AREA
PIN 1 ID
SEE DETAIL A
24
1
0.50
BSC
2.50
2.80
0.18
0.30
6
13
0.35
0.45
TOP VIEW
12
7
BOTTOM VIEW
PIN 1 ID OPTION A
0.30x45º TYP.
PIN 1 ID OPTION B
R0.25 TYP.
0.80
1.00
0.20 REF
0.00
0.05
DETAIL A
SIDE VIEW
3.90
2.70
0.70
0.25
NOTE:
1) ALL DIMENSIONS ARE IN MILLIMETERS.
2) EXPOSED PADDLE SIZE DOES NOT INCLUDE MOLD FLASH.
3) LEAD COPLANARITY SHALL BE0.10 MILLIMETER MAX.
4) DRAWING CONFIRMS TO JEDEC MO-220, VARIATION VGGD.
5) DRAWING IS NOT TO SCALE.
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.
MP2626 Rev. 1.0
2/28/2015
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34