MP2617H

– SINGLE-CELL SWITCHING CHARGER WITH NVDC POWER PATH

MP2617H Rev. 1.03

www.MonolithicPower.com

20

1/15/2018

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© 2018 MPS. All Rights Reserved.

MP2617H stops charging and reports this on

the

indication

pins.

Charging

resumes

automatically after the temperature falls back

into the safe range.

Thermal Protection

The MP2617H implements thermal protection to

prevent

thermal

damage

to

the

IC

or

surrounding components. An internal thermal

sense and feedback loop decrease the charge

current automatically when the die temperature

rises to about 120°C. This function is referred to

as the charge current thermal fold-back. This

feature protects the MP2617H from excessive

temperature due to high-power operation or

high

ambient

thermal

conditions.

Another

benefit of this feature is that the charge current

can be set according to the requirement rather

than the worst-case condition for a given

application with the assurance of safe operation.

The MP2617H stops charging if the junction

temperature rises above 150°C as the IC enters

thermal shutdown protection.

Ideal Diode Mode

If the system current requirement increases

such that the pre-set input current limit of the

PWM converter is reached and the charge

current has reduced to zero, the additional

current will be drawn from the battery via the

BATT-to-SYS switch. To avoid very large

currents from being drawn from the battery

which might affect the reliability of the device,

the MP2617H controls the battery MOSFET to

MOSFET exits ideal diode mode, and the

charge cycle restarts softly.

Enable Ideal Diode Mode

Disable Ideal Diode Mode

Figure 4: Ideal Diode Mode Enable/Disable

Battery Discharge Protection

When the input power is removed or invalid, the

system load draws power from the battery via

the battery switch. Under this condition, the

battery switch is fully on to minimize power loss.

The MP2617H integrates battery discharge

protection. If the battery discharge current is

larger than the discharge current limit threshold

set limited value. If the current increases further,

condition is detected. Under this condition, the

discharge current is limited at 230mA. In the

event of a short from the system to GND, the

discharge current from the battery to the system

is also limited to 230mA.

The battery voltage UVLO is always monitored.

If the battery voltage is lower than the battery

UVLO threshold, the battery switch is turned off

immediately. This feature prevents the battery

from being over-discharged.

Dynamic Power Path Management (DPPM)

In the presence of a valid input source, the

PWM converter supplies current to both the

system and the battery charger.

constant 3.6V to ensure that the system can still

be powered up, even with a drained battery

connected.

When the input source is overloaded, either the

current exceeds the input current limit or the

voltage falls below the input voltage limit. The

MP2617H then reduces the charge current until

the input current falls below the input current

limit and the input voltage rises above the input

voltage limit. If the system current increases

beyond the power allowed by the input source,

additional power is drawn from the battery via

an on-

chip 40mΩ MOSFET working as an ideal

diode. If the system current increased further,

when the discharge current times the Ron is

BATT to SYS MOSFET just turned fully on, the

battery powers the system together with the

converter from VIN as the supplement mode.