NCL30083_15 datasheet(21/35 Pages) ONSEMI

Part #	NCL30083

Description	Dimmable Quasi-Resonant Primary Side Current-Mode Controller for LED Lighting with Thermal Fold-back

PDF	35 Pages

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Manufacturer	ONSEMI [ON Semiconductor]

Direct Link	http://www.onsemi.com

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NCL30083

www.onsemi.com

At startup, when VCC reaches VCC(on), the controller is

not allowed to start pulsing for at least 180

ms in order to

allow the SD pin voltage to reach its nominal value if a

filtering capacitor is connected to the SD pin. This is to avoid

flickering of the LED light in case of over temperature.

VCCreset

VCC

Vdd

OTP_Timer end

noise delay

Rclamp

Vclamp

Latch

NTC

OTP

OVP

(OTP latched for version A)

4−s Timer

OFF

0.5 V if OTP low

0.7 V if OTP high

Figure 58. Thermal Fold−back and OVP/OTP Circuitry

VOVP

IOTP(REF)

VTF

VOTP

In case of over voltage, the Zener diode starts to conduct

and inject current inside the internal clamp resistor Rclamp

thus causing the pin SD voltage to increase. When this

voltage reaches the OVP threshold (2.5 V typ.), the

controller shuts−down and waits for at least 4 seconds before

restarting switching.

NCL30083 Datasheet(PDF) 21 Page - ON Semiconductor