FLS3217 FAIRCHILD [Fairchild Semiconductor], FLS3217 Datasheet - Page 11

• Manufacturer Part Number: FLS3217
• Description: Single-Stage PFC Primary-Side-Regulation Offline LED Driver with Integrated Power MOSFET
• Manufacturer: FAIRCHILD [Fairchild Semiconductor]

© 2012 Fairchild Semiconductor Corporation
FLS3217 / FLS3247 • Rev. 1.0.0
Under-Voltage Lockout (UVLO)
The turn-on and turn-off thresholds are fixed internally at
16V and 7.5V, respectively. During startup, the VDD
capacitor must be charged to 16V through the startup
resistor, so that the FLS32x7 is enabled. The VDD
capacitor supplies VDD until power can be delivered
from the auxiliary winding of the main transformer. VDD
must not drop below 7.5V during startup. The UVLO
hysteresis window ensures that the VDD capacitor is
adequate to supply VDD during startup.
Figure 22. Waveforms at Open-LED Condition
Over-Temperature Protection (OTP)
The built-in temperature-sensing circuit shuts down
PWM output once the junction temperature exceeds
150°C. While PWM output is off, VDD gradually drops to
the UVLO voltage. Some of the internal circuits are shut
down and VDD gradually increases again. When VDD
reaches 16V, all the internal circuits start operating. If
the junction temperature is still higher than 140°C, the
PWM controller shuts down immediately.
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