L6699D datasheet(31/38 Pages) STMICROELECTRONICS

Part #	L6699D

Description	Enhanced high voltage resonant controller

PDF	38 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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31 / 38 page

L6699

Line sensing function

Doc ID 022835 Rev 2

31/38

Figure 22.

Line sensing function: internal block diagram and timing diagram

While the line undervoltage is active there is no switching activity, therefore the VCC voltage

(if not supplied by another source) continuously oscillates between the startup and the

UVLO thresholds, as shown in the timing diagram of

Figure 22.

The LINE pin, while the device is operating, is a high impedance input connected to high

value resistors, so it is prone to pick-up noise,. This might alter VinOFF or give rise to

undesired switch-off of the IC during ESD tests. It is possible to bypass the pin to ground

with a small film capacitor (e.g. 1-10 nF) to prevent any malfunctioning of this kind.

If the function is not used the pin can be pulled high by connecting it to VCC through a

resistor in the hundred k

Ω.

L6699D Datasheet(PDF) 31 Page - STMicroelectronics