STEVAL-ILL027V1 STMicroelectronics, STEVAL-ILL027V1 Datasheet - Page 11

• Manufacturer Part Number: STEVAL-ILL027V1
• Description: BOARD EVAL LED DRIVER FOR L6562A
• Manufacturer: STMicroelectronics

Specifications of STEVAL-ILL027V1

• Design Resources: STEVAL-ILL027V1 Schematics STEVAL-ILL027V1 BOM STEVAL-ILL027V1 Gerber Files
• Current - Output / Channel: 260mA
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 70V
• Features: Short-Circuit Protection
• Voltage - Input: 120VAC
• Utilized Ic / Part: L6562A
• Product: Display Modules
• Lead Free Status / RoHS Status: Lead free by exemption / RoHS compliant by exemption
• Other names: 497-10170

AN3111
Figure 7.
Figure 8.
LED voltage and LED current
Figure 8
than the output voltage, zero voltage turn-on is achieved. When the input voltage is higher
than the output voltage, the MOSFET is turned on at reduced voltage.
Fault conditions:
1.
If the LED string is disconnected from the circuit, the output capacitor can be charged to
a very high voltage if there is no overvoltage protection. The protection threshold voltage
Vovp is set as 75 V. R7 and R10 sense the reflected voltage through the coupled inductor
with a 4 to 1 turn ratio (N). The error amplifier of the L6562A is used to shut down the chip if
overvoltage is detected.
Switching waveform of MOSFET
Q1: conclusions when Vout > Vin
Open load
and
9
show the MOSFET switching waveforms. When the input line voltage is lower
Doc ID 16815 Rev 2
Figure 9.
Switching waveform of MOSFET
Q1: conclusions when Vout < Vin
Circuit design
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