STEVAL-ILL027V1 STMicroelectronics, STEVAL-ILL027V1 Datasheet - Page 8

• 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

Circuit design
8/23
The frequency is:
Equation 5
The switching frequency varies during the line cycle, which is good for EMI.
The max. frequency occurs at peak input voltage:
Equation 6
The input power is:
Equation 7
Equation 8
The integration term of
only. There is no simple solution form for the integration term. The average value of the input
voltage and duty cycle can be used to perform the estimation. After Ipk is calculated, the
inductance can be determined according to the desired switching frequency range.
The average input voltage over half-cycle at 120 VAC line is:
Equation 9
The average duty cycle is:
Equation 10
Therefore:
Equation 11
After the current is determined, it is necessary to choose the right inductance value. The
inductance affects the running frequency. The maximum switching frequency below 200 kHz
has been chosen.
Equation 8
fsw
Doc ID 16815 Rev 2
fsw
P
(
P
θ
Vave
=
Ipk
)
max
=
Dave
is a constant value, so the power is determined by Ipk
=
2
1
∫
0
T
1
π
=
*
1
2
=
Ipk
=
=
2
1
=
*
∫
L
0
L
L
*
π
*
Vave
Vpk
*
Vave
*
*
1
∫
1
Ipk
Ipk
Ipk
0
π
( D
Pin
Vout
*
(
2
θ
(
+
sin(
Vpk
*
Vout
Vin
* )
Vout
*
Vout
Dave
fsw
Vin
θ
(
θ
+
d )
*
(
)
*
(
Vout
θ
+
θ
Vpk
θ
=
Vin
)
=
dt
d )
Vout
=
0.333
1.2 A
θ
108 V
(
θ
)
)
)
AN3111