ME4057

V01

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Board Layout Considerations

●R

PROG at PROG pin should be as close to ME4057 as possible, also the parasitic capacitance at PROG pin should

be kept as small as possible.

●The capacitance at V

CC pin and BAT pin should be as close to ME4057 as possible.

● During charging, ME4057’s temperature may be high, the NTC thermistor should be placed far enough to ME4057

so that the thermistor can reflect the battery’s temperature correctly.

● It is very important to use a good thermal PC board layout to maximize charging current. The thermal path for the

heat generated by the IC is from the die to the copper lead frame through the package lead (especially the ground

lead) to the PC board copper, the PC board copper is the heat sink. The footprint copper pads should be as wide

as possible and expand out to larger copper areas to spread and dissipate the heat to the surrounding ambient.

Feed through vias to inner or backside copper layers are also useful in improving the overall thermal performance

of the charger. Other heat sources on the board, not related to the charger, must also be considered when

designing a PC board layout because they will affect overall temperature rise and the maximum charge current.

●The ability to deliver maximum charge current under all conditions require that the exposed metal pad on the back

side of the ME4057 package be soldered to the PC board ground. Failure to make the thermal contact between the

exposed pad on the backside of the package and the copper board will result in larger thermal resistance.