L6563S STMicroelectronics, L6563S Datasheet - Page 29

• Manufacturer Part Number: L6563S
• Description: IC PFC CTRLR TRANSITION 14SOIC
• Manufacturer: STMicroelectronics

Specifications of L6563S

• Mode: Discontinuous (Transition)
• Current - Startup: 90µA
• Voltage - Supply: 10.3 V ~ 22.5 V
• Operating Temperature: -40°C ~ 150°C
• Mounting Type: Surface Mount
• Package / Case: 14-SOIC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

L6563S
V(TBO)/RT, that is internally 1:1 mirrored and sunk from pin INV (#1) input of the L6563S's
error amplifier. In this way, when the mains voltage increases the voltage at TBO pin will
increase as well and so will do the current flowing through the resistor connected between
TBO and GND. Then a larger current will be sunk by INV pin and the output voltage of the
PFC pre-regulator will be forced to get higher. Obviously, the output voltage will move in the
opposite direction if the input voltage decreases.
To avoid undesired output voltage rise should the mains voltage exceed the maximum
specified value, the voltage at the TBO pin is clamped at 3V. By properly selecting the
multiplier bias it is possible to set the maximum input voltage above which input-to-output
tracking ends and the output voltage becomes constant. If this function is not used, leave
the pin open: the device will regulate a fixed output voltage.
Starting from the following data:
●
●
●
●
●
to set the output voltage at the desired values use the following design procedure:
1.
2.
3.
4.
5.
Figure 40
Vin
Vin
Vo
Vo
Vox = absolute maximum limit for the regulated output voltage;
Determine the input RMS voltage Vinclamp that produces Vo = Vox:
and choose a value Vin
of the output voltage range below Vox (it will equal Vox if one chooses Vin
Determine the divider ratio of the MULT pin (#3) bias:
and check that at minimum mains voltage Vin1 the peak voltage on pin 3 is greater than
0.65 V.
Determine R1, the upper resistor of the output divider, for instance 3 MΩ.
Calculate the lower resistor R2 of the output divider and the adjustment resistor RT:
Check that the maximum current sourced by the TBO pin (#6) does not exceed the
maximum specified (0.2 mA):
1
2
1
2
= regulated output voltage @ Vin = Vin
= regulated output voltage @ Vin = Vin
= minimum specified input RMS voltage;
= maximum specified input RMS voltage;
shows the internal block diagram of the tracking boost function.
⎧
⎪ ⎪
⎨
⎪
⎪
⎩
R
R
Vin
2
T
=
=
clamp
2
x
5 .
2
such that Vin
Doc ID 16116 Rev 4
⋅
⋅
=
R
k
1
⋅
I
Vox
Vo
TBO
R
⋅
(
1
Vo
2
⋅
max
Vin
−
−
Vo
1
k
Vo
Vo
−
=
2
2
=
2
2
1
1
−
−
5 .
R
≤
3
⋅
2
Vin
Vo
T
)
Vin
Vinx < Vinclamp. This will result in a limitation
⋅
⋅
3
Vin
≤
Vin
Vin
1
1
2
1
2
;
;
0
2 .
−
2
x
2
−
Vox
−
Vo
⋅
10
(
Vin
Vo
2
−
−
3
−
1
2
Vo
Vo
−
2
2
1
5 .
⋅
)
Vin
⋅
Vin
Application information
1
1
x
= Vin
clamp
29/43
)