LTC3203/LTC3203-1

LTC3203B/LTC3203B-1

9

32031fa

When the output voltage drops enough to overcome the

burst comparator hysteresis, the part wakes up and com-

mences normal fixed frequency operation. The output

capacitor recharges and causes the part to re-enter the

Sleep state if the output load still remains less than the

Burst Mode threshold. This Burst Mode threshold varies

Short-Circuit/Thermal Protection

The LTC3203/LTC3203-1/LTC3203B/LTC3203B-1 have

built-in short-circuit current limit as well as over-tempera-

ture protection. During a short-circuit condition, the chip

will automatically limit the output current to approximately

1A. At higher temperatures, or if the input voltage is high

enough to cause excessive self-heating of the part, the

thermal shutdown circuitry will shut down the charge

pump once the junction temperature exceeds approxi-

mately 150

°C. It will enable the charge pump once the

junction temperature drops back to approximately 135

°C.

The LTC3203/LTC3203-1/LTC3203B/LTC3203B-1 will

cycle in and out of thermal shutdown indefinitely without

latch-up or damage until the short circuit condition on

Soft-Start

the LTC3203/LTC3203-1/LTC3203B/LTC3203B-1 have

built-in soft-start circuitry. Soft-start is achieved by in-

creasing the amount of current available to the output

charge storage capacitor linearly over a period of approxi-

mately 250

µs.

OPERATIO