MP2617A, MP2617B

– SINGLE CELL SWITCHING CHARGER WITH POWER PATH

MP2617A, MP2617B Rev. 1.23

www.MonolithicPower.com

18

1/15/2018

MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.

© 2018 MPS. All Rights Reserved.

When both M0 and M1 pins are float, they are

pulled to the logic high, under this condition, the

input current is limited to a default value of 2A.

Table 2

―Input Current Limit Setting

M0

M1

Mode

Low

Low

USB2.0 Mode

Low

High

USB3.0 Mode

High

Low

Programmable Mode

High/Float

High/Float

Default Mode

Input Voltage Limit Setting

The input voltage can be limited at a value set by

a resistor divider from IN pin to VLIM pin to

AGND according to the following expression

(Typical Application Circuit):

IN_LIM

R1+R2

V

=1.52

(V)

R2



When the voltage on VLIM pin drops and hits the

reference voltage 1.52V, the input voltage will be

clamped to the setting value.

Battery Charger

The MP2617A and MP2617B completes charge

operation consist of trickle charge, automatic

charge termination, charge status indication,

timer control, NTC indication, automatic recharge,

and thermal limiting.

When the PWM converter is out of soft start, the

battery charge cycle begins, the MP2617A and

MP2617B first determines if the battery is deeply

discharged. If the battery voltage is lower than

the trick charge threshold (typical 3.0V), the

battery charger starts in

“trickle charge mode”.

The trickle charge current is limited to 10% of the

programmed charge current until the battery

voltage reaches 3.0V. If the charge stays in the

“trickle charging mode” for longer than ”trickle

charge timer period”, the “timer out” condition is

triggered, the charge is terminated and CHGOK

_____________

will start blinking to indicate that the battery is

unresponsive. When the battery voltage is above

3.0

V, the charger is operating at “constant

current mode.” The current delivered to the

battery will try to reach the value programmed by

the ISET pin. Depending on the available input

power and system load conditions, the battery

charger may or may not be able to charge at the

full programmed rate. The system load is always

satisfied first over the battery charge current. If

the system load requirement is low, the battery

can be charged at full constant current.

When the battery voltage reaches the battery full

threshold, the charger

enters the “constant

voltage mode

” operation.

End of Charge (EOC) and Indication

In constant voltage charge mode, the battery

voltage is regulated at 4.2V (MP2617B) and

4.35V (MP2617A) (when SYSFB is float or SYS

is programmed higher than battery full threshold)

and the charge current decreases naturally.

Once the charge current hits the battery full

the battery is fully charged and charge cycle is

terminated.

any limit condition, the MP2617A and MP2617B

will come out of CV mode, and the charge full

detection is invalid.

A safe timer starts at the beginning of each new

charge cycle and it monitors if the whole charge

period is within the programmed time limit. After

each charge cycle, when the battery is indicated

as full, the timer counter will be reset. If the time

is expired while the charging is still on going, the

timer will force the MP2617A and MP2617B to

terminate charging CHGOK

_____________

is blinking to indicate

the fault condition.

If system voltage is programmed lower than 4.2V

(MP2617B) and 4.35V (MP2617A) by the resistor

divider at the SYSFB pin, the battery will be

Automatic Recharge

Once the battery charge cycle is completed, the

MP2617A and MP2617B turns off indicating the

battery full status. During this process, the

battery power may be consumed by the system

load or self discharge. If the input power is

always on, to ensure the battery not to be

exhausted,

the

new

charge

cycle

will

automatically begin when the battery voltage falls

the SYSFB is float, and 50mV lower if the SYSFB

is connected to a resistor divider. The timer will

re-start when the auto-recharge cycle begins.