SARA-R4/N4 series - System Integration Manual
UBX-16029218 - R11 Design-in Page 67 of 157
The MP2617H IC normally provides a supply voltage to the module regulated from the external main
primary source allowing immediate system operation even under missing or deeply discharged battery: the
integrated switching step-down regulator is capable to provide up to 3 A output current with low output
ripple and fixed 1.6 MHz switching frequency in PWM mode operation. The module load is satisfied in
priority, then the integrated switching charger will take the remaining current to charge the battery.
Additionally, the power path control allows an internal connection from battery to the module with a low
series internal ON resistance (40 m typical), in order to supplement additional power to the module when
the current demand increases over the external main primary source or when this external source is
removed.
Battery charging is managed in three phases:
Pre-charge constant current (active when the battery is deeply discharged): the battery is charged with
a low current, set to 10% of the fast-charge current
Fast-charge constant current: the battery is charged with the maximum current, configured by the
value of an external resistor to a value suitable for the application
Constant voltage: when the battery voltage reaches the regulated output voltage (4.2 V), the current is
progressively reduced until the charge termination is done. The charging process ends when the
charging current reaches the 10% of the fast-charge current or when the charging timer reaches the
value configured by an external capacitor
Using a battery pack with an internal NTC resistor, the MP2617H can monitor the battery temperature to
protect the battery from operating under unsafe thermal conditions.
Several parameters as the charging current, the charging timings, the input current limit, the input voltage
limit, the system output voltage can be easily set according to the specific application requirements, as the
actual electrical characteristics of the battery and the external supply / charging source: suitable resistors
or capacitors must be accordingly connected to the related pins of the IC.
To Next Page
Loading...
Need help?
General
