CS1500 Digital PFC Controller
ULTRA HIGH EFFICIENCY POWER FACTOR CORRECTION IC
LEARN MORE AT
www.cirrus.com
POWER MANAGEMENT
CIRRUS LOGIC, INC.
2901 Via Fortuna
Austin, Texas 78746
United States
T +1-512-851-4000
Toll-Free +1-800-888-5016
SALES SUPPORT
North America +1 800-625-4084
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Europe/UK +44 (90) 1628-891-300
NOTEBOOK ADAPTERS
DIGITAL TELEVISIONS
PC POWER SUPPLIES
AC Mains
Regulated
DC Output
CS1500
NC NC
IAC
VDD STBY
GND GD
FB
OVERVIEW
The CS1500 is a high-performance Variable Frequency
Discontinuous Mode, active digital power factor
correction (PFC) controller. It features Cirrus Logic’s
EXL Core™ technology that brings digital energy
control innovation which elevates performance and
solves system design challenges in power supplies
used in notebook adapters, digital TVs and PCs.
The unique digital architecture of the CS1500
enables reduced-size EMI filters and eliminates the
need for numerous passive components, delivering
the lowest PFC system costs available.
Variable on-time / variable frequency algorithm is
used to achieve close to unity power factor and shaping
the EMI noise spectrum, thus reducing the conducted
EMI filtering size and cost. The feedback loop is closed
through an integrated compensation network within the
IC, eliminating the need for additional external
components. Protection features (such as overvoltage,
overpower, open and short circuit protection, over-
temperature, and brownout) help protect the device
during abnormal transient conditions.
FEATURES
Ultra High Efficiency •
Digital EMI Noise Shaping •
Digital Over-Current Protection •
Variable Frequency DCM for Light Load Efficiency •
Comprehensive On-Chip Protection •
EXL CORE TECHNOLOGY
The EXL Core is a digital
technology platform at the heart of
Cirrus Logic’s commitment to
develop innovative solutions that
help our customers cost effectively
create smarter, greener energy products
CS1500 8-PIN SOIC
(actual size: 5 mm x 5 mm)
POWER MANAGEMENT | CS1500 DIGITAL POWER FACTOR CORRECTION
©2010 Cirrus Logic, Inc. All rights reserved. Product information is subject to change without notice. Cirrus Logic, Cirrus, the Cirrus Logic logo designs, EXL Core, and the EXL Core
logo design are trademarks of Cirrus Logic, Inc. Other brand and product names may be trademarks or service marks of their respective owners. Product Bulletin 823106-0610-PB
CS1500 uses a proprietary digital control algorithm
to shape conducted EMI emissions, resulting in
significantly reduced EMI filter requirements.
Digital EMI Noise Shaping consists of three major
components:
Variable switching frequency •
The average switching frequency is varied
°
with respect to the line voltage spreading
energy over a wide frequency band.
The switching frequency is highest at the peak of
°
the input voltage which minimizes peak currents
Digital Spread Spectrum •
Shapes colored noise eliminating EMI noise spikes
°
Peak current amplitude spreading •
Provides additional spreading and further
°
reduces EMI peaks.
KEY VALUES
Digital noise shaping dramatically decreases •
the size and cost of the EMI filter
Variable frequency DCM enables superior •
efficiency under all load conditions
Low external component count •
Comprehensive on-chip protection •
Under Voltage Lockout
°
Over Voltage
°
Over Power
°
Brownout
°
Open Loop
°
EVALUATION MODULES AND REFERENCE DESIGNS
CDB-CS1500- 100W PFC Only •
CRD-CS1500-FB 75 W Notebook Adapter •
Reference Design
CRD-CS1500-LLC 90 W Notebook Adapter •
Reference Design
CRD-CS1500-LLC 250 W TV/PC Power •
Reference Design
REFERENCE DESIGN 90W CS1500 + FLYBACK
CS1500 Digital PFC + Flyback second stage
demonstrates the expected performance of Cirrus
Logic new digital energy controller. The combined
solution allows a simple one layer board and world
class efficiencies under all load conditions.
CS1500’s Digital EMI Noise Shaping enables
the simplification and reduction of EMI filter
components allowing for smaller more efficient
designs at any power level.
REFERENCE DESIGN 90W CS1500 + LLC
Demonstrating ultra high efficiency, the
CS1500+LLC reference design provides the best
efficiency and smallest EMI filter for power levels
up to 300 W. The Digital EMI Noise Shaping is
utilized to shape both PFC and 2nd differential
and common mode EMI noise. Efficiencies for this
design are ~90% with unmatched performance
under all load conditions with considerable power
dissipation advantages under light load and no
load conditions. This solution can be referenced
for the development of high end laptop adaptors,
PC Power, and low profile DTV Power.
REFERENCE DESIGN 230W CS1500 + LLC
This reference design demonstrates CS1500’s
unique ability to mitigate EMI noise, even at higher
rated power level. Typical power supply designs
for power levels > 200 W previously required more
expensive Continuous Conduction Mode (CCM)
technology, but with Cirrus Logic’s Digital EMI
Noise Shaping technology, cost effective
Discontinuous Conduction Mode (DCM) topologies
can scale up to 300 W. Cirrus Logic EXL Core
technology enables the optimization of switching
frequency and duty cycle, for all power levels, line
voltages, and load conditions, thus providing users
with the optimal energy controller for any PFC
enabled product.
For the full datasheet, visit
www.cirrus.com/support.
90
75
60
45
30
100 300 500
Conducted EMI Comparison
Frequency (kHz)
dBuV
CS1500 Digital PFC
Leading Analog PFC
EMI Limit
Part Number
Control Method
Max fSW [kHz]
Frequency
Spereading
Peak Current
Spreading
IC Supply
Current [mA]
VDD Range [V]
TJ Op. Range [°C]
Gate Driver
(Source/Sink) [Ω]
Internal Feedback
Compensation
Package
CS1500
VF-DCM 70 √ √ 1.9 7.9 – 17.0 -40 to +125 9 / 6 √SOIC-8
