MP2615BGQ [MPS]
2A, 1 Cell Li-ion Battery Charger In 3mm x 3mm Package;
| 型号： | MP2615BGQ |
| 厂家： | 
MONOLITHIC POWER SYSTEMS |
| 描述： | 2A, 1 Cell Li-ion Battery Charger In 3mm x 3mm Package 电池 |
| 文件： | 总20页 (文件大小：881K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MP2615B
2A, 1 Cell Li-ion Battery Charger
In 3mm x 3mm Package
The Future of Analog IC Technology
DESCRIPTION
FEATURES
The MP2615B is a monolithic switching charger
for a 1 cell lithium-Ion or lithium-Polymer battery
packed with built-in power MOSFETs. It’s able
to achieve up to 2A charge current which can
be programmed via an accurate sense resistor
over the whole input range.
•
•
•
•
•
4.5V to 18V Operating Input Voltage
Up to 99% Duty Cycle Operation
Up to 2A Programmable Charging Current
±0.75% Full Battery Voltage Accuracy
4.03V and 3.99V Selection for Full Battery
Voltage
•
•
•
Full Integrated Power Switches
Internal Loop Compensation
No External Reverse Blocking Diode
Required
MP2615B regulates the charge current and full
battery voltage using two control loops to
realize high accuracy constant current (CC)
charge and constant voltage (CV) charge.
•
•
•
•
•
•
Preconditioning for Fully Depleted Battery
Charging Operation Indicator
Programmable Safety Timer
Thermal Shutdown Protection
Cycle-by-Cycle Over Current Protection
Battery Temperature Monitor and Protection
Thanks to the constant-off-time (COT) mode
control, 99% duty cycle can be achieved when
battery voltage is close to the input voltage to
keep the charge current always at a relative
high level.
Battery temperature and charging status are
always monitored for each condition. Two
status monitor output pins are provided to
indicate the battery charging status and input
power status. The MP2615B also features
internal reverse blocking protection.
APPLICATIONS
•
•
•
Smart Phones
Portable Hand-held Solutions
Portable Media Players
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.
The MP2615B is available in QFN-16
(3mmx3mm) package.
“MPS” and “The Future of Analog IC Technology” are registered trademarks of
Monolithic Power Systems, Inc.
ADAM (Analog Digital Adaptive Modulation) and AAM (Advanced Asynchronous
Mode) are trademarks of Monolithic Power Systems, Inc.
TYPICAL APPLICATION
L
RS1
5V/ 9V Input
90
SW
VIN
R2
R1
C7
BST
CHGOK
85
ACOK MP2615B CSP
Battery
C2
VREF
BATT
TMR
SEL
80
RNTC
R3
NTC
EN
75
ON
OFF
CTMR
AGND
CELL
PGND
70
0
0.5
1
1.5
2
2.5
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
1
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
ORDERING INFORMATION
Part Number*
MP2615BGQ
Package
QFN-16 (3mmx3mm)
Top Marking
AJC
* For Tape & Reel, add suffix –Z (e.g. MP2615BGQ–Z);
PACKAGE REFERENCE
TOP VIEW
16
15
14
13
12
SW
VIN
1
2
3
11
CHGOK
CSP
10
9
VCC
BATT
4
5
6
7
8
ABSOLUTE MAXIMUM RATINGS (1)
VSW.................................................–0.3V to 23V
VIN, VACOK, VCHGOK............................................–0.3V to 23V
Thermal Resistance (4)
QFN-16 (3mmx3mm)..............50...... 12... °C/W
θJA
θJC
Notes:
V
V
BATT, VCSP............................................................–0.3V to 12V
BST ......................................................VSW + 6V
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-to-
ambient 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.
All Other Pins...................................–0.3V to 6V
Junction Temperature...............................150°C
Lead Temperature ....................................260°C
(2)
Continuous Power Dissipation (TA = +25°C)
............................................................. 2.5W
Operating Temperature............. –40°C to +85°C
3) The device is not guaranteed to function outside of its
operating conditions.
4) Measured on JESD51-7, 4-layer PCB.
Recommended Operating Conditions (3)
VIN ....................................................4.5V to 18V
VBATT.................................................2V to 4.03V
Operating Junction Temp. (TJ).–40°C to +125°C
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
2
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
ELECTRICAL CHARACTERISTICS
VIN = 12V, VCELL = 0V, VSEL = 0V, C1 = 22µF, C2=22µF, TA = 25°C, unless otherwise noted.
Parameter
Symbol Condition
Min
Typ
Max
Units
Input Voltage and Curren
Input Voltage
VIN
Cell Float
4.5
12
18
V
V
Under
Threshold Rising
Under Voltage
Voltage
Lockout
Lockout
VUVLO
3.55
3.75
3.95
225
mV
mA
Threshold Hysteresis
ISHDN
IQ
0.27
1.1
= 4V, Shutdown Current
EN
EN
Supply Current
= 0V, Quiescent Current
Power MOS
High-side
Resistance
Switch
Switch
On
On
RH_DS(ON) Measured from VIN to SW
RL_DS(ON)
110
mΩ
Low-side
Resistance
110
0
mΩ
μA
Switch Leakage
Frequency and Time Parameter
1
= 4V, VSW = 0V
EN
Switching Frequency
Fold-back Frequency
Minimum Off Time (5)
Charging Parameter
FSW
VBATT = 3.8V,
VBATT = 0V,
760
160
200
kHz
kHz
ns
TOFF
VBATT = 4.5V,
VSEL = 0V
4.01
3.91
4.06
3.96
4.03
3.93
4.19
4.09
3.9
4.05
3.95
4.32
4.22
Terminal Battery Voltage
VBATT_FULL
VSEL = 4V
VSEL = 0V
VSEL = 4V
VSEL = 0V
Battery
Over
Voltage
VBOVP
V
Threshold
Recharge Threshold at VBATT VRECH
Recharge Hysteresis
VSEL = 4V
3.8
50
mV
V
VSEL = 0V
SEL = 4V
2.97
2.9
Trickle
Threshold
Charge
Voltage
VTC
V
Trickle Charge Hysteresis
Peak Current Limit
220
4.2
mV
A
CC(5)
3.2
Trickle
2.2
CC Current
ICC
ITC
RS1 = 50mΩ
1.8
5%
2
2.2
A
Trickle Charge Current
10%
15%
ICC
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
3
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
ELECTRICAL CHARACTERISTICS (continued)
VIN = 12V, VCELL = 0V, VSEL = 0V, C1 = 22µF, C2=22µF, TA = 25°C, unless otherwise noted.
Parameter
Symbol Condition
Min
Typ
Max
Units
Termination
Threshold
Current
IBF
5%
10%
15%
ICC
VIN minimum Head-room
(reverse blocking)
VIN − VBATT
300
100
mV
mV
Maximum Current Sense
Voltage
(CSP to BATT)
VSENSE
90
110
0.5
CSP, BATT Current
ICSP, IBATT Charging disabled
VDRAIN = 0.3V
µA
ACOK/CHGOK Open-drain
Sink Current
5
mA
VCC Regulator Output
VCC Output Voltage
VCC Load Regulation
EN Control
VCC
4.25
4.5
4.75
10
V
∆VCC
ILOAD=0 to 10mA
mV
0.4
V
V
EN Input Low Voltage
EN Input High Voltage
1.9
4
= 4V
= 0V
EN
EN
IEN
μA
EN Input Current
0.2
Timer Protection
Trickle Charge Time
CC/CV Charge Time
NTC Protection
tTrickle_tmr CTMR = 0.47uF
tTotal_tmr CTMR = 0.47uF
30
Mins
165
NTC Low Temp Rising
Threshold
RNTC=NCP18X103, 0°C(6)
70.5
28
73.3
2
74.6
30.6
TA= –20°C to +85°C(5)
NTC Low Temp Rising
Threshold Hysteresis
%VCC
NTC High Temp Falling
Threshold
RNTC=NCP18X103,50°C(6)
TA= –20°C to +85°C(5)
29.3
2
NTC Low Temp Falling
Threshold Hysteresis
Thermal Protection
Thermal Shutdown(5)
TSHDN
150
20
°C
°C
Thermal
Shutdown
Hysteresis(5)
Reverse Leakage Blocking
Battery Reverse Leakage
Current
ILEAKAGE
0.5
µA
Notes:
5) Guaranteed by design.
6) The operation temperature limit when using the specified NTC resistor.
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
4
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
TYPICAL PERFORMANCE CHARACTERISTICS
VIN=12V, C1=C2=22μF, SEL=VCC, CELL=Float, L=6.2μH, RS1=50mΩ, Battery Simulator, TA=25°C,
unless otherwise noted.
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
5
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN=12V, C1=C2=22μF, SEL=VCC, CELL=Float, L=6.2μH, RS1=50mΩ, Battery Simulator, TA=25°C,
unless otherwise noted.
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
6
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN=12V, C1=C2=22μF, SEL=VCC, CELL=Float, L=6.2μH, RS1=50mΩ, Battery Simulator, TA=25°C,
unless otherwise noted.
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
7
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN=12V, C1=C2=22μF, SEL=VCC, CELL=Float, L=6.2μH, RS1=50mΩ, Battery Simulator, TA=25°C,
unless otherwise noted.
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
8
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN=12V, C1=C2=22μF, SEL=VCC, CELL=Float, L=6.2μH, RS1=50mΩ, Battery Simulator, TA=25°C,
unless otherwise noted.
.
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
9
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
PIN FUNCTIONS
Package
Pin #
Name Description
1
2
SW
VIN
Switch Output
Power Supply Voltage.
Coarse Regulator Output. Internally generated 4.5V. Bypass with a 1µF capacitor to AGND.
Used to be low-side switch driver and pull-up bias voltage NTC resistive divider. Do not
connect any external load at this pin.
3
4
5
VCC
CELL Keep the pin float or connect to GND.
Input Pin for Setting Terminal Battery Voltage:
SEL = Low-level or Float: VBATT = 4.03V
SEL = High-level: VBATT =3.99V
SEL
6
7
On/ Off Control Input. This pin is pulled down to GND with a 1Meg internal resistor.
EN
N/C
NO CONNECT. Please leave this pin floating.
8
AGND Analog Ground.
9
BATT Positive Battery Terminal.
10
CSP
Battery Current Sense Positive Input. Connect a resistor RS1 between CSP and BATT.
Charging Completion Indicator. A logic Low indicates charging operation. The pin will
become an open drain once the charge is completed or suspended.
11
12
13
14
CHGOK
Valid Input Supply Indicator. A logic Low on this pin indicates the presence of a valid input
power supply.
ACOK
NTC
Thermistor Input. Connect a resistor from this pin to the pin VCC and the thermistor from
this pin to ground.
Internal Safety Timer Control. Connect a capacitor from this node to AGND to set the timer.
And the timer can be disabled by connecting this pin to AGND directly.
TMR
Bootstrap. This capacitor is needed to drive the power switch’s gate above the supply
voltage. It is connected between SW and BST pins to form a floating supply across the
power switch driver.
15
16
BST
PGND Power Ground.
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
10
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
FUNCTIONAL BLOCK DIAGRAM
VIN
Current Sense
IHS
A1
BST
PRE _ REGS
VREF
OSC
EN
Regulator
CTRL
Drive
M1
5 bit trim
Current Limit
Comparator
S
Q
R
R
M2
M3
SW
LDO
COMP
VCC
NTC
PWM
Comparator
L
BATT
Charge
Current Sense
CSP
FB
COMPV
A2
0.123 V
or 1.23 V
RS 1
GMI
GMV
BATT
cells
OVP
COMPI
1.23V
battery
CTRL
ICHG
TMR
SEL
Timer
CELLS
TC /CC
Charge
OVP
Comparator
Comparator
FB
OVP
1.23V
0. 879 V
Charge Control
Logic
Recharge
Comparator
ACOK
Comparator
FB
VIN
1.171 V
BF
VBATT +0.2V
Comparator
ICHG
ACOK
CHGOK
0.123 V
AGND
PGND
Figure 1: Functional Block Diagram
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
11
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
OPERATION
The MP2615B is a peak current mode controlled
switching charger for a 1 cell lithium-ion and
lithium-polymer batteries. It integrates both the
high-side and low-side switches of the
synchronous BUCK converter, which provides
high efficiency and saves the PCB space.
charge mode till the trickle-charge timer is
triggered, the charging will be terminated.
The MP2615B will enter constant-current charge
mode once the battery voltage rises higher than
VTC, and in this mode the current loop continues
dominating the control and the charge current will
increase from ITC to ICC to fast charge the battery
Charge Cycle (Mode change: TCÆ CCÆ CV)
The MP2615B regulates the charge current (ICHG
and battery voltage (VBATT) using two control
loops to realize highly-accurate constant current
(CC) charge and constant voltage (CV) charge.
)
When the battery voltage rises over full battery
voltage VBATT_FULL, the charger enters into
constant-voltage mode. In constant voltage mode,
the battery voltage is regulated at VBATT_FULL
precisely and the charge current will fall naturally
due to the existing equivalent internal resistance
of the battery. For the operation flow chart,
please also refer to Figure 4.
As shown in Figure 2, when the VBATT < VTC, the
MP2615B stays in trickle-charge mode and the
output of charge current loop COMPI dominants
the control. The battery is charged by a trickle
charge current ITC until the battery voltage
reaches VTC. If the charger stays in the trickle-
CVCharge
Threshold
Auto-recharge
Threshold
CC Charge
Current
ICHG
VBATT
CC Charge
Threshold
IBF
TC Charge
Current
CC
Charge
CV
Charge
Charge
Full
Auto-
recharge
Trickle
Charge
Figure 2: Li-ion Battery Charge Profile
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
12
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
Charge Full Termination and Auto-Recharge
and GND is used to set the internal oscillator
period,
When the charge current drops below the
termination threshold (IBF) during the CV charge
phase, the charger will stop charging and the
TP(seconds) = 0.46×CTMR(uF)
(1)
This timer limits the max trickle charge time to
8192 internal oscillating period. If the charger
stays in trickle charge mode for longer than the
max oscillating periods, it will be terminated and
CHGOK pin becomes open drain. The timer will
also be reset and turned off. Once the battery
voltage decrease below the recharge threshold
VRECH, recharging will automatically kick in and
the CHGOK becomes open drain to indicate the
timer-out fault. If the charge successfully goes
through trickle charge within the allowed time
limit, it enters into the CC charge mode and the
timer continues to count the oscillating periods.
When the battery is charged full, the timer turns
off and clears the counter, waiting for the auto-
recharge to restart.
the timer restarts a new charge cycle.
COT Charge Mode
MP2615B uses the floating ground method to
drive the high-side MOSFET of the buck
converter. During the off-time of the high-side
MOSFET, the BST capacitor is recharged and
the voltage across it is used as the HS-MOS gate
drive. Thus a minimum off-time 200ns is required
to maintain sufficient voltage at BST capacitor.
When the 200ns minimum off-time is achieved
due to a large duty cycle, the MP2615B enters
into the COT (constant off-time) charge mode. In
this mode of operation, Switching frequency is
decreased in order to achieve up to 99% duty
cycle.
If the charge time during CC/CV mode exceeds
49152 oscillating periods and the battery full has
not been qualified, the charger will be terminated
and a timer-out fault is also indicated by floating
the CHGOK . The charger can exit the timer-out
fault state and the on-chip safety timer restarts
counting when one of the following conditions
occurs:
Charge Status Indication
MP2615B has two open-drain status outputs,
•
The battery voltage falls below the auto-
recharge threshold VRECH
.
CHGOK pin and ACOK pin. The ACOK pin
goes low when the input voltage is 300mV larger
than battery voltage and over the under voltage
•
•
A power-on-reset (POR) event occurs;
EN pin is toggled.
lockout threshold. Pin CHGOK is used to indicate
the status of the charge cycle. Table 1
The timer can be disabled by pulling TMR-pin to
AGND.
summarized the operation of both CHGOK and
Thus, the trickle mode charge time is:
ACOK according to the status of charge.
tTrickle_tmr (minutes) = 62.8×CTMR(uF)
(2)
Table 1: Charging Status Indication
Charger Status
ACOK
Low
CHGOK
Low
If connect a CTMR of 0.47uF, the trickle charge
time is about 30 minutes.
In charging
End of charge;
NTC fault;
The CC/CV mode charge time is:
High
impedance
Timer out;
Low
tTotal_tmr (hours) = 6.28×CTMR(uF)
(3)
EN disable;
Thermal shutdown;
VIN absent;
VIN − VBATT < 0.3V
If connect a CTMR of 0.47uF, the CC/CV charge
time is 2.95 hours.
High
High
impedance impedance
Safety Timer Operation
The MP2615B has an internal safety timer to
terminate charging if the timer times out. The
capacitor CTMR connected between the TMR pin
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
13
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
Negative
Thermal
Coefficient
(NTC)
Thermistor
The NTC pin allows MP2615B to sense the
battery temperature using the Negative Thermal
Coefficient (NTC) resistor available in the battery
pack to ensure safe operating environment of the
battery. A resistor with appropriate value should
be connected from VCC to NTC pin and the
thermistor is connected from NTC pin to AGND.
The voltage on NTC-pin is determined by the
resistor divider whose divide-ratio depends on
the battery temperature. When the voltage at
NTC pin falls out of the NTC window range, the
charging will pause until battery temperature
goes back into the normal operation conditions
As a result the MP2615B will stop charging and
report this condition to the status pins, the timer
will also be suspended but will continue counting
from where they left off when charging resumes.
Short Circuit Protection
The MP2615B has an internal comparator to
check for battery short circuit. Once VBATT falls
below 2V, the device detects a battery-short
status and the cycle-by-cycle peak current limit
falls to about 2.2A to limit the current spike during
the battery-short transition. Furthermore, the
switching frequency also folds back to minimize
the power loss.
Thermal Shutdown Protection
To prevent the chip from overheating during
charging, the MP2615B monitors the junction
temperature, TJ, of the die. Once TJ reaches the
thermal shutdown threshold (TSHTDWN) of 150°C,
the charger converter turns off. Once the TJ falls
below 130°C the charging will restart.
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
14
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
INPUT POWER UP START UP TIMING FLOW
3. 75V
VBATT + 300 mV
2V
VIN
Band Gap
VCC
UVLO
ACOK
CHGOK
AC Ready
1.23V
Soft Start
Charge Ready
Force- charge
1.5ms
200 mA
250 mA
Charge Current
IBF Comparator
Auto- recharge
Initial State
Higher than3 V
assummed)
(
Auto- recharge
threshold
Battery Voltage
Figure 3: Input Power Start-up Timing Diagram
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
15
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
OPERATION FLOW CHART
POR
No
VIN>VUVLO
&
VIN>VBATT+0.3V ?
Yes
ACOK is low
No
Charging
Set up?
Yes
Normal Operation
Fault Protection
Charge On
CHGOK is low
No
No
Charge
V
<
Charge Mode?
VBATT
REG
Yes
Timer Out?
Termination,
Or Enable restart ?
CHGOK is high
Yes
VBATT=VBATT_ FULL
VTC =VBATT<VBATT_ FULL
VBATT<VTC
T.C.C
No
No
C.V.C
C.C.C
Return to
Normal
Operation
Cease Charging,
CHGOK is high
NTC Fault?
Yes
NTC OK?
Yes
No
No
No
ICHG<IBF
Yes
?
VBATT=VBATT_FULL
Yes
VBATT>VTC
Yes
No
No
Battery Ful,l
Cease Charging,
CHGOK is high
Thermal Shutdown,
CHGOK is high
o
o
Tj>=150 C?
Yes
Tj=130 C?
Yes
Yes
No
VBATT <VRECHG
Auto- recharge?
Figure 4: Operation Flow Chart
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
16
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
APPLICATION INFORMATION
COMPONENT SELECTION
Charge Current Setting
To optimize efficiency, chose an inductor with a
DC resistance less than 50mꢀ.
NTC Resistor Divider Selection
The constant charge current (ICC) of MP2615B
can be set by the sense resistor RS1 (see
Typical Application). The equation to determine
the programmable CC-charge current is
expressed as following,
Figure 5 shows that an internal resistor divider
sets the low temperature threshold and high
temperature threshold at 73.3%·VCC and
29.3%·VCC, respectively. For a given NTC
100mV
VCC
(4)
ICC
=
(A)
RS1(mΩ)
To get 2A ICC, a RS1 of 50mꢀ should be selected.
Low Temp Threshold
VTH_Low
RT1
Accordingly, the trickle charge current (ITC) can
be obtained by the following equation,
10mV
NTC
(5)
ITC = 10%ICC
=
(A)
RNTC
RT2
RS1(mΩ)
Inductor Selection
High Temp Threshold
VTH_High
For inductor selection, a trade off should be
made between cost, size, and efficiency. An
inductor of lower inductance value corresponds
with smaller size, but results in higher ripple
currents, higher magnetic hysteretic losses, and
higher output capacitances. Conversely, higher
inductance value is beneficial to getting a lower
ripple current and smaller output filter capacitors,
but resulting in higher inductor DC resistance
(DCR) loss. According to the practical experience,
the inductor ripple current should not exceed
15% of the maximum charge current under worst
cases. For a MP2615B with a typical 12V input
voltage to charge a 1-cell battery, the maximum
inductor current ripple occurs at the corner point
Figure 5: NTC Function Block
thermistor, select appropriate RT1 and RT2 to set
the NTC window.
The thermistor (NCP18XH103) noted above has
the following electrical characteristic:
•
•
At 0°C, RNTC_Cold = 27.445kꢀ;
At 50°C, RNTC_Hot = 4.1601kꢀ.
The following equations are derived assuming
that the NTC window is between 0°C and 50°C:
RT2//RNTC_Cold
V
TH_Low
(8)
(9)
=
=73.3%
RT1 +RT2//RNTC_Cold VREF33
between trickle charge and CC charge (VBATT
3V). Estimate the required inductance as:
=
RT2//RNTC_Hot
VTH_High
=
= 29.3%
V - VBATT VBATT
RT1 +RT2//RNTC_Hot VREF33
IN
(6)
L =
ΔIL_MAX V ⋅ fS
IN
According to Equation (8) (9), and the required
battery temperature range to calculate RT1 and
RT2.
where VIN, VBATT, and fS are the typical input
voltage, the CC charge threshold, and the
switching frequency, respectively. And ΔIL_MAX is
the maximum inductor ripple current, which is
usually 30% of the CC charge current.
ΔIL_MAX = 30%ICC
(7)
For the condition that ICC = 2A, VIN = 12V, VBATT
=
3V and fs = 760kHz the calculated inductance is
4.93µH. The inductor saturant current must
exceed 2.6A at least and have some tolerance.
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
17
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
For VIN_MAX = 18V, VCC_MIN = VTC =3V, L = 4.7µH,
fS = 760kHz, ∆RO_MAX = 0.2%, the output
capacitor can be calculated as,
Input Capacitor Selection
The input capacitors C1 from the typical
application circuit absorbs the maximum ripple
current from the buck converter, which is given
by:
VTC
1-
V
IN _ MAX
C0 =
=19.2(μF)
(12)
8fs2LΔr0 _ MAX
VTC (V
VTC )
IN_MAX
IRMS_MAX =ICC
(10)
V
IN_MAX
We can then choose a 22µF ceramic capacitor.
For a given ICC = 2A, VTC = 3V, VIN_MAX = 18V, the
maximum ripple current is 1A. Select the input
capacitors so that the temperature rise due to the
ripple current does not exceed 10°C. Use
ceramic capacitors with X5R or X7R dielectrics
because of their low ESR and small temperature
coefficients. For most applications, use a 22µF
capacitor.
PCB Layout Guide
PCB layout is 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 high-current paths and the
current-sense resistor trace. Keep the
switching node short and away from the
feedback network.
Output Capacitor Selection
The output capacitor C2 (see the typical
application circuit) is in parallel with the battery.
C2 absorbs the high-frequency switching ripple
current and smoothes the output voltage. Its
impedance must be much less than that of the
battery to ensure it absorbs the ripple current.
Use a ceramic capacitor because it has lower
ESR and smaller size that allows us to ignore the
ESR of the output capacitor. Thus, the output
voltage ripple is given by,
2) Connect the charge current sense resistor
to CSP (pin 10), BATT (pin 9). Minimize
the length and area of this circuit loop.
3) Place the input capacitor as close as
possible to the VIN and PGND pins. Place
the output inductor close to the IC as and
connect the output capacitor between the
inductor and PGND of the IC. This
minimizes the current path loop area from
the SW pin through the LC filter and back
to the PGND pin.
VO
1-
ΔVO
VO
V
IN
(11)
ΔrO =
=
2
8COfS L
In order to guarantee the ± 0.5% full battery
voltage accuracy, the maximum output voltage
ripple must not exceed 0.5% (e.g.0.1%). The
maximum output voltage ripple occurs at the
minimum battery voltage of the CC charge and
the maximum input voltage.
4) Connect AGND and PGND at a single
point.
5) Figure 6 is a PCB layout reference design.
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
18
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
Figure 6: MP2615B PCB Guild Design
TYPICAL APPLICATION CIRCUITS
Figure 7: Typical Application Circuit with 12VIN.
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
19
MP2615B – 2A, 1- CELL LI-ION BATTERY CHARGER
PACKAGE INFORMATION
QFN-16 (3mmx3mm)
PIN 1 ID
MARKING
PIN 1 ID
0.10x45° TYP.
PIN 1 ID
INDEX AREA
TOP VIEW
BOTTOM VIEW
SIDE VIEW
NOTE:
0.10x45°
1) ALL DIMENSIONS ARE IN MILLIMETERS.
2) EXPOSED PADDLE SIZE DOES NOT INCLUDE
MOLD FLASH.
3) LEAD COPLANARITY SHALL BE0.10
MILLIMETERS MAX.
4) JEDEC REFERENCE IS MO-220.
5) DRAWING IS NOT TO SCALE.
RECOMMENDED LAND PATTERN
NOTICE: The information in this document is subject to change without notice. Please contact MPS for current specifications.
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.
MP2615B Rev. 1.0
3/17/2016
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
20
相关型号：
MP2617H
Wide input Voltage, 3A, Switching Charger With NVDC Power Path Management For Single Cell Li Battery
MPS
MP2617HGL
Wide input Voltage, 3A, Switching Charger With NVDC Power Path Management For Single Cell Li Battery
MPS
MP2618EV-LF
Power Supply Support Circuit, Adjustable, 1 Channel, 4 X 5 MM, ROHS COMPLIANT, MO-220VHGD-3, QFN-28
MPS
MP2618EV-LF-Z
Power Supply Support Circuit, Adjustable, 1 Channel, 4 X 5 MM, ROHS COMPLIANT, MO-220VHGD-3, QFN-28
MPS
©2020 ICPDF网 联系我们和版权申明