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CV adjustment

Battery termination voltage default set to 12.6V. If other CV voltage wanted, the follow equations

change the CV voltage.

If increase CV voltage, connect a resistor from FBADJ to GND. the increased voltage determined by:

If decrease CV voltage, connect a resistor from battery to FBADJ, the decreased voltage determined

by

Rdivup=156K

Rdivdown=156K/5 for 3cell

Shutdown

The

HM5083 can be shut down by pulling the NTC pin to VIN. When the NTC pin is released, the internal

timer is reset and a new charge cycle starts.

Inductor Selection

A operating frequency was chosen for the buck switcher in order to minimize the size of the inductor.

However, take care to use inductors with low core loss at this frequency. To calculate the inductor

ripple current:

Charge Status Indicator (STAT)

The charge status output has two different states: strong pull-down (~5mA) and high impedance. The

strong pull-down state indicates that the

HM5083 is in a charge cycle. Once the charge cycle has

terminated, the pin state is determined by under voltage lockout conditions. High impedance indicates

that the charge cycle complete.

Layout Considerations

Switch rise and fall times are kept under 5ns for maximum efficiency. To minimize radiation, the SW pin

and input bypass capacitor leads (between VIN and GND) should be kept as short as possible. A

ground plane should be used under the switching circuitry to prevent inter plane coupling. The

Exposed Pad must be connected to the ground plane for proper power dissipation. The other paths

contain only DC and/or 500KHz tri-wave ripple current and are less critical. With the exception of the

input and output filter capacitors (which should be connected to GND) all other components that return

to ground.

2.1

=

divup

trim

VR

R



2.1

divdown

trim

V

VR

R





3A Synchronous Buck 3 Cells Li-ion Charger

HM5083