DS12866 Rev 1

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HVLED007

Application information

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Vcc supply voltage is high enough to define its state) to reset the COMP voltage.

Figure 11 shows the functional schematic of the OVP circuit.

formula:

Equation 18

value is defined by other application parameters (see "Section 4.8: Zero current detection

and triggering block (pin ZCD); starter").

Figure 11. Functional schematic of the OVP function

4.11

Soft-restart function

This function provides a smooth converter restart limiting the initial primary peak current

(pin COMP)") or after an overvoltage detection (see "Section 4.10: Overvoltage protection

(OVP function)").

This goal is met by turning on a MOSFET switch connected between pin CT and ground that

Firstly, the discharge switch is kept in the ON-state as long as the IC is in UVLO (provided its

Vcc supply voltage is high enough to define its state) to reset the CT voltage at start-up.

Secondly, the discharge switch is turned on as long as the IC is stopped and is turned off

shows the block diagram of the circuit implementing the above-mentioned functionality.

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