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Theory of operation, An349, Comp vcc gnd – Cirrus Logic AN349 User Manual

Page 4: Zcd inv, Mult

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AN349

4

AN349REV1

Figure 5. Ballast Startup with CS1601

4. Theory of Operation

Figure 4 and Figure 5 are the internal block diagrams of the L6562 and the CS1601, respectively.

Figure 6. L6562 Block Diagram

4

CS

7

GD

2

COMP

VCC

GND

V

CC

8

V

Ref2

Starter

Stop

R1

+

-

+

-

Voltage

Regulator

Overvoltage

Detection

R2

40k

Multiplier & THD

Optimizer

Disable

Driver

25V

+

-

R

S

Q

+

-

5

ZCD

INV

1

UVLO

6

Starter

2.1V
1.6V

Zero Current

Detector

15V

5pF

MULT

3

Internal

Supply 7V

2.5V