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2 layout considerations – Garmin MC34676B User Manual

Page 8

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Using the Dual 28V Input Voltage Charger with Linear Regulator,

Rev. 1.0

8

Freescale Semiconductor

Layout Design

6.2

Layout considerations

• Place decoupling capacitors C1, C3 and C4 as close as possible to the AC pin, USB pin and BAT pin respectively.
• Place the charge current setting resistor as close as possible to the current setting pin to minimize the parasitic

capacitance between the current setting pin and ground.

• Use wide traces to connect input power source to the AC pin and USB pin, and BAT pin to the battery.
• To get better thermal performance, put the EPAD pin of the MC34676B on a large ground plane on the component

side, and use a via array to connect the EPAD pin to the ground layer, or the large ground plane on the other layer.