EVL6562A-LED STMicroelectronics, EVL6562A-LED Datasheet - Page 10

• Manufacturer Part Number: EVL6562A-LED
• Description: EVALUATION MODULE L6562A
• Manufacturer: STMicroelectronics
• Type: Power Factor Correctionr

Specifications of EVL6562A-LED

• Current - Output / Channel: 350mA
• Outputs And Type: 1, Non-Isolated
• Features: Dimmable
• Voltage - Input: 48V
• Utilized Ic / Part: L6562A
• Input Voltage: 48 V
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: L6562A
• Other names: 497-10420

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Circuit description
This causes the gate driver to go high again and then the power MOSFET to conduct.
The time delay toff is simply governed by the equation of the discharge of the capacitor C8
through the resistor R18 with the boundary conditions V (t0) = 5.7 V, V (t1) = 0.7 V.
Equation 7
Equation 8
Equation 9
With our values this gives:
Equation 10
Refer to AN2782
waveforms with the LEDs’ current (I_LED), capacitor (C8) voltage (V_C8) and gate drive
output voltage (V_GD).
Figure 9.
It is worth noting that the real toff time is 1.57 µS and that the low threshold is 0.44 V. This is
due to the components’ tolerance and to the propagation delay from the comparator input to
the gate driver output.
b. See
Chapter 5: References on page
toff delay (actual)
(b)
for a detailed description of the FOT controller.
toff
=
R (
18
Doc ID 15679 Rev 1
*
C
toff
30.
ln
8
( V
* )
⎡
⎢
⎣
) t
=
V
1
( V
ln
t (
R (
=
⎡
⎢
⎣
) t
1
0
5
0
18
)
V
7 .
7 .
⎤
⎥
⎦
t (
*
=
⎤
⎥
⎦
0
C
* )
=
−
8
⎡
⎢
⎣
* )
. 2
e
R
−
* 1
18
ln
⎡
⎢
⎣
toff
R
⎡
⎢
⎣
R (
18
*
(toff)
V
( V
C
*C
t (
18
8
) t
8
0
1
⎤
⎥
⎦
*
⎤
⎥
⎦
)
⎤
⎥
⎦
C
8
)
=
. 1
17
Figure 9
μ
S
shows the key
AN2983