Cirrus Logic CS160x User Manual

MUR160

F1 4A

t NTC1 30

NO POP - SHORT WITH 28 AWG WIRE

C1 2200pF

2200pF

0.22uF

BR1

GBU4J-BP

600V

NO POP

0.33uF

MUR460G

600V

NTC2

NO POP, SHORT WITH AWG28 WIRE

R8 20K

CON2

TERM BLK

CON1

TERM BLK

R3 1M

R20

48.7K

R2 1M

R13 1M

R18

1.78K

V300LA20AP 300V

IND-5MH-TSD-2796

5mH

NO POP, SHORT PIN 1-2 & PIN 3-4 wi th 28 AWG wire

IND-5MH-TSD-2796

5mH

CON3

TERM BLK

1PAD-H78P108A21PAD-H78P108

R19 100

100uF

ELEC

R12

R11

C10

4.7uF

VBIAS2

STBY

IRECT

ILINK5GND

VDD

VBIAS1

CS1500-FSZ

NO POP

HS1

12.5W

C12

100pF

SDG

Q1 STP12NM50FP

NO POP, SHORT WITH AWG28 WIRE

380uH

RLCS-1007

R17 NO POP

NO POP

R21

NO POP

R22 NO POP

NO POP

R10

NO POP

LL4148

IFB

IAC

CS5ZCD

GND

VDD

CS1501-FSZ

C11

33pF

R14 1M

4.7 OHM

TP8

TP2

TP3

TP4

TP5

TP6

TP7

NO POP

R16 0

R23

R15 1M

JP1

0.800" WIRE JUMPER

C14

1000pF

X7R

NO POP

C13

1000pF

X7R

C15

1000pF

X7R

NO POP

R1 1M

0.1 1W

AN346

Application Note

CS150x & CS160x PCB LAYOUT GUIDELINES

1. INTRODUCTION

The CS150x & CS160x are high-performance variable frequency discontinuous conduction mode (VFDCM), active digital power factor correction (PFC) controllers. The CS1500/CS1501 are intended for use in power supplies, and the CS1600/CS1601 are targeted for lighting applications.

This document describes best layout practices for these devices, using the CS1500/CS1600 & CS1501/CS1601 90W PFC demonstration board, CDB150x as an example. This board has dual footprints to allow either the CS1500/CS1600 or CS1501/CS1601 to be fitted. The layout guidelines presented in this application note are also applicable to lighting designs. In th is docu ment, all refere nces will be to the CS1500 and CS1501.

Note: The CS1501 uses two additional pins. Pin 4 (CS) is used for current sense. Pin 5 (ZCD) is used for zero current detection (valley switching detection). These pins are not present on the CS1500 and are not connected. Although these functions are not present on the CS1500, the gen eral layout principles are the same. For a full description of these functions, please refer to the CS1501 & CS1601 data sheets

Figure 1. Schematic of a 90W PFC System with CS1500/CS1501

In the schematic above U1 refers to CS1501 and U2 refers to CS1500. Assembly instructions are provided for using either the CS1500 or CS1501.

http://www.cirrus.com

APR ‘11

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Contacting Cirrus Logic Support

For all product questions and inquiries contact a Cirrus Logic Sales Representative. To fi nd the one nearest to you go to www.cirrus.com

IMPORTANT NOTICE

Cirrus Logic, Inc. and its subsidiaries ("Cirrus") b eli eve that the information contained in this d oc um e nt i s accu ra te and reliable. However, the information is subject to change without notice and is provided "AS IS" without warranty of any kind (express or implied). Customers are advised to obtain the latest version of relevant information to verify, before placing or ders, that inform ation be ing r elied on is curren t and com plete. A ll pro ducts are sold su bject to the term s and con dition s of sale supplied at the time of order ackno wledgment, includin g those pertaining to w arranty, indemnificatio n, and limitation of li ability. No responsibility is assumed by Cirrus for the use of this information, including use of this information as the basis for manufacture or sale of any items, or for infringement of patents or other rights of third parties. This document is the property of Cirrus and by furnishing this information, Cirrus grants no license, express or implied under any patents, mask work rights, copyrights, trade marks, tra de secrets or other int ellectual property r ights. Cirr us owns the co pyrights a ssociated wit h the inf ormation co ntained her ein and gi ves consent for copies to be made of the informa tion only for use within yo ur or gani zation w ith resp ect to Cirru s inte grated cir cuits or other p rodu cts of C irrus. This co nsent does not extend to other copying such as copying for general distribution, advertising or promotional purposes, or for creating any work for resale.

CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (" CRITICAL APPLICATI ONS"). CIRRUS PRODUCT S ARE NOT DESIGNED, AUTHORIZED OR WARRANTED FOR USE IN PRODUCTS SURGICALLY IMPLANTED INTO THE BODY, AUTOMOTIVE SAFETY OR SECURITY DEVICES, LIFE SUPPORT PRODUCTS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF CIRRUS PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER'S RISK AND CIRRUS DISCLAIMS AND MAKES NO WARRANTY, EXPRESS, STATUTORY OR IMPLIED, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR PARTICULAR PURPOSE, WITH REGARD TO ANY CIRRUS PRODUCT THAT IS USED IN SUCH A MANNER. IF THE CUSTOMER OR CUSTOMER'S CUSTOMER USES OR PERMITS THE USE OF CIRRUS PRODUCTS IN CRITICAL APPLICATIONS, CUSTOMER AGREES, BY SUCH USE, TO FULLY INDEMNIFY CIRRUS , ITS OFFI CERS, DI RECTORS, EMPLOY EES, DISTRI BUTORS AND OTHER AGENTS F ROM ANY AND ALL LIA BILITY, IN CLUDING ATTORNEYS' FEES AND COSTS, THAT MAY RESULT FROM OR ARISE IN CONNECTION WITH THESE USES.

Cirrus Logic, Cirrus, and the Cirrus Logic logo designs are trademarks of Cirrus Logic, Inc. All other brand and product names in this document may be trademarks or service marks of their respective owners.

IMPORTANT SAFETY INSTRUCTIONS

Read and follow all safety instructions prior to using this demonstration board.

This Engineering Evaluation Unit or Demonstration Board must only be used for assessing IC performance in a laboratory setting. This product is not intended for any other use or incorporation into products for sale.

This product must only be used by qualified technicians or professionals who are trained in the safety procedures associated with the use of demonstration boards.

Risk of Electric Shock

• The direct connection to the AC power line and the open and unprotected boards present a serious risk of electric shock and can cause serious injury or death. Extreme caution needs to be exercised while handling this board.

• Avoid contact with the exposed conductor or terminals of components on the board. High voltage is present on exposed conductor and it may be present on terminals of any components directly or indirectly connected to the AC line.

• Dangerous voltages and/or currents may be internally generated and accessible at various points across the board.

• Charged capacitors store high voltage, even after the circuit has been disconnected from the AC line.

• Make sure that the power source is off before wiring any connection. Make sure that all connectors are well

connected before the power source is on.

• Follow all laboratory safety procedures established by your employer and relevant safety regulations and guidelines, such as the ones listed under, OSHA General Industry Regulations - Subpart S and NFPA 70E.

Suitable eye protection must be worn when working with or around demonstration boards. Always

comply with your employer’s policies regarding the use of personal protective equipment.

All components, heat sinks or metallic parts may be extremely hot to touch when electrically active.

Heatsinking is required for Q1. The end product should use tar pitch or an equivalent compound for this

purpose. For lab evaluation purposes, a fan is recommended to provide adequate cooling.

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EMI Filter Boost PFC Sect ion

Low Voltage IC Section

2. PCB LAYOUT

Figure 1 and Figure 2 show a schematic and layout for a 90W PFC stage. The board is a single-layer PCB with through-hole components on the top side, surface-mou nt components & signal routing on the bottom.

Figure 2. Single-layer PCB Layout for a 120W PFC-only Application Using the CS1500

The following sections demonstrate the best layout practices when designing a system using the CS1500/CS1501.

2.1 Power Layout Recommendations

The following are good layout guidelines for a PFC stage or fluorescent ballast.

– Keep the main power components such as inductor, FET, diode, and outpu t bulk capacitor as close

together as possible. Minimize trace impedance by keeping connections as short & wide as

possible. Fast power switching currents generate noise in proportion to the trace impedance. – The power-stage ground and the signal ground must be separated. – Input decoupling capacitors should be placed close to the inductor. – EMI filter should be placed as close to AC inlet as possible. – The MOSFET gate drive loop length should be minimized, as shown in Figure 3. This applies to

both the positive (drive) path & return (GND). – Current sense resistor return (GND) should be close to the output bulk capacitor negative (GND)

to reduce interference with the IC.

Figure 3. Gate-to-Ground Current Paths Between CS1501 and MOSFET

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