XC6408 datasheet(13/34 Pages) TOREX

13 / 34 page

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XC6408

Series

■ OPERATIONAL EXPLANATION

The voltage divided by resistors R11 & R12 is compared with the internal reference voltage by the error amplifier. The

P-channel MOSFET which is connected to the VROUT pin is then driven by the subsequent output signal. The output voltage

at the VROUT pin is controlled and stabilized by a system of negative feedback. The current limit circuit, short protect circuit

and thermal protection circuit operate in relation to the level of output current and heat generation. For the XC6408E,

regulator operation returns active state when VSEN pin voltage rises higher than the release voltage (*when VSEN pin voltage

is higher than detect voltage + hysteresis voltage).

The XC6408 series includes a current fold-back circuit as a short circuit protection. When the load current reaches the

current limit, the current fold-back circuit starts to operate. As a result, the output voltage drops further and output current

decreases. When the VROUT pin is short-circuited, a flow current minimizes to around 30mA.

When the junction temperature of the built-in driver transistor reaches the temperature limit level (150℃ TYP.), the thermal

shutdown circuit operates and the driver transistor will be set to OFF. The IC resumes its operation when the thermal

shutdown function is released and the IC’s operation is automatically restored because the junction temperature drops to the

level of the thermal shutdown release voltage.

For the stable operation of the IC, over 2.0V of input voltage is necessary. The output voltage may not be generated

normally if the input voltage is less than 2.0V.

XC6408 D Type

XC6408 E Type

XC6408 Datasheet(PDF) 13 Page - Torex Semiconductor