SGM4056 Datasheet, PDF (13/19 Pages) SG Micro Corp – High Input Voltage Charger

SGM4056
APPLICATION INFORMATION
Input Capacitor Selection
The input capacitor is required to suppress the power
supply transient response during transitions. Mainly this
capacitor is selected to avoid oscillation during the start
up when the input supply is passing the POR threshold
and the VIN-BAT comparator offset voltage. When the
battery voltage is above the POR threshold, the V_IN - V_BAT
offset voltage dominates the hysteresis value. Typically,
a 1µF X5R ceramic capacitor should be sufficient to
suppress the power supply noise.
Output Capacitor Selection
The criterion for selecting the output capacitor is to
maintain the stability of the charger as well as to bypass
any transient load current. The minimum capacitance is a
1µF X5R ceramic capacitor. The actual capacitance
connected to the output is dependent on the actual
application requirement.
High Input Voltage Charger
Layout Guidance
The SGM4056 uses thermally-enhanced TDFN and
SOIC packages that have an exposed thermal pad at the
bottom side of the packages. The layout should connect
as much as possible to copper on the exposed pad.
Typically the component layer is more effective in
dissipating heat. The thermal impedance can be further
reduced by using other layers of copper connecting to the
exposed pad through a thermal via array. Each thermal
via is recommended to have 0.3mm diameter and 1mm
distance from other thermal vias.
Input Power Sources
The input power source is typically a well-regulated wall
cube with 1-meter length wire or a USB port. The
SGM4056 can withstand up to 26.5V on the input without
damaging the IC. If the input voltage is higher than
typically 6.8V (SGM4056-6.8) or 10.5V (SGM4056-10.5),
the charger stops charging.
SG Micro Corp
13
www.sg-micro.com