Application information
L6563 - L6563A
5. Check that the maximum current sourced by the TBO pin (pin 6) does not exceed the
maximum specified (0.25mA):
Equation 10
ITBOmax
=
---3---
RT
≤0.25
⋅
10–3
In the following Mathcad® sheet, as an example, the calculation is shown for the circuit
illustrated in Figure 39 shows the internal block diagram of the tracking boost function.
Design data
Vin1 := 88V
Vin2 := 264V
Vox ;= 400V
∆Vo ;= 40V
Vo1:= 200V
Vo2:= 385V
Step 1
Vinclamp:
=
-V----o----x----–-----V----o---1--
Vo2 – Vo1
⋅
Vin2
–
-V----o----x----–-----V----o---2-
Vo2 – Vo1
⋅
Vin1
Vinclamp = 278.27V
choose: Vinx: = 270V
Step 2
k: = ------------3--------------
2 ⋅ Vinx
k = 7.857 x 10-3
Step 3
R1:
=
∆----V-----o-
20
⋅
106
R1 = 2 x 106 Ω
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