LTC4091

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4091fa

For more information www.linear.com/LTC4091

Many types of capacitors can be used for input bypassing;

whilerecommended,cautionmustbeexercisedwhenusing

multilayer ceramic capacitors. Because of the self-reso-

nant and high Q characteristics of some types of ceramic

capacitors,highvoltagetransientscanbegeneratedunder

some start-up conditions, such as from connecting the

chargerinputtoahotpowersource.Formoreinformation,

refer to Application Note 88.

Battery Charger Stability Considerations

The constant-voltage mode feedback loop is stable with-

out any compensation when a battery is connected with

low impedance leads. Excessive lead length, however,

may add enough series inductance to require a bypass

capacitor of at least 1µF from BAT to GND. Furthermore,

a 100µF capacitor with a 50mΩ series resistor to GND is

recommended at the BAT pin to keep ripple voltage low

when the battery is disconnected.

APPLICATIONS INFORMATION

Figure 10. Ground Currents Follow Their Incident Path at High Speed. Slices in the Ground Plane Cause High

Voltage and Increased Emissions.

4091 F11