Cirrus Logic reserves the right to modify this product without notice.

Copyright

 Cirrus Logic, Inc. 2011

(All Rights Reserved)

Cirrus Logic, Inc.

http://www.cirrus.com

CS1601

CS1601H

Digital PFC Controller for Electronic Ballasts

Inductor Size

Design

• Undervoltage Lockout (UVLO)

• Output Overvoltage Protection

• Cycle-by-cycle Current Limiting

• Input Voltage Brownout Protection

• Open/Short Loop Protection for IAC & IFB Pins

• Thermal Shutdown

Controllers

Overview

The CS1601 and CS1601H are digital power factor correction

(PFC) controllers designed to deliver the lowest PFC system

cost in electronic ballast applications. The controller operates

in a variable frequency discontinuous conduction mode (VF-

DCM) with zero-current switching (ZCS) optimized to deliver

best-in-class THD and minimize the size and cost of magnetic

components. The CS1601 operates at switching frequencies

up to 70 kHz while the CS1601H operates at frequencies

extending to 100kHz.

The VF-DCM control algorithm varies both duty cycle and

frequency. This spreads the EMI frequency spectrum, thus

reducing conducted EMI filtering requirements. In addition, the

maximum switching frequency is reached at the peak of the AC

input, which allows for use of a smaller, more cost-effective

boost inductor.

The feedback loop is closed through an integrated

compensation network within the controller, eliminating the

need for additional external components. Protection features

such as overvoltage, overcurrent, open and short-circuit

protection, overtemperature, and brownout protect the system

during abnormal transient conditions.

Ordering Information

See page 15.

R1

R2

R3

R4

R7

R5

R6

8

1

D1

C1

C2

Regulated

DC Output

Q1

AC

Mains

BR 1

BR1

BR 1

BR1

CS1601

CS1601H

GD

ZCD

IFB

GND

CS

IAC

VDD

6

3

57

4

STBY

2

JUN ’11

DS931PP6