Maximum Load Under Start-Up

Due to the LM3354’s unique start-up sequence, it is not able

to start up under all load conditions. Starting with 60 mA or

less will allow the part to start correctly under any tempera-

ture or input voltage conditions. After the output is in regu-

lation, any load up to the maximum as specified in the

Electrical Characteristics may be applied. Using a Power On

Reset circuit, such as the LP3470, is recommended if

greater start up loads are expected. Under certain conditions

the LM3354 can start up with greater load currents without

the use of a Power On Reset Circuit.

Thermal Protection

During output short circuit conditions, the LM3354 will draw

high currents causing a rise in the junction temperature.

On-chip thermal protection circuitry disables the charge

pump action once the junction temperature exceeds the

thermal trip point, and re-enables the charge pump when the

junction temperature falls back to a safe operating point.

Typical Application Circuits

20057333

FIGURE 2. Basic Buck/Boost Regulator

20057315

FIGURE 3. Low Output Noise and Ripple Buck/Boost Regulator

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