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AN42

APPLICATION NOTE

 

2/98 0.0m

Stock#AN30000042

 1998 Fairchild Semiconductor Corporation

LIFE SUPPORT POLICY 
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES 
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR 
CORPORATION.  As used herein:

1. Life support devices or systems are devices or systems 

which, (a) are intended for surgical implant into the body, 
or (b) support or sustain life, and (c) whose failure to 
perform when properly used in accordance with 
instructions for use provided in the labeling, can be 
reasonable expected to result in a significant injury of the 
user.

2. A critical component in any component of a life support 

device or system whose failure to perform can be 
reasonably expected to cause the failure of the life support 
device or system, or to affect its safety or effectiveness.

www.fairchildsemi.com

Fairchild Semiconductor 
Corporation 

Americas 

Customer Response Center

Tel:1-888-522-5372

Fairchild Semiconductor

Europe

Fax:

+49 (0) 1 80-530 85 86

Email:

[email protected]

Deutsch Tel:

+49 (0) 8 141-35-0

English

Tel:

+44 (0) 1 793-85-68-56

Italy

Tel:

+39 (0) 2 57 5631

Fairchild Semiconductor

Hong Kong Ltd.

13th Floor, Straight Block,

Ocean Center, 5 Canto Rd.

Tsimshatsui, Kowloon

Hong Kong

Tel:+852 2737-7200

Fax:+852 2314-0061

National Semiconductor

Japan Ltd.

Tel:81-3-5620-6175

Fax:81-3-5620-6179

Appendix A: Directory of Component Suppliers 

Dale Electronics, Inc.
E. Hwy. 50, PO Box 180
Yankton, SD 57078-0180
PH: (605) 665-9301

Fuji Electric
Collmer Semiconductor Inc.
14368 Proton Rd.
Dallas, Texas 75244
PH: (214)233-1589

General Instrument
Power Semiconductor Division
10 Melville Park Road
Melville, NY 11747
PH: (516) 847-3000

Hoskins Manufacturing Co.
(Copel Resistor Wire)
10776 Hall Road
Hamburg, MI 48139-0218
PH: (313) 231-1900

Intel Corp. 
5200 NE Elam Young Pkwy.
Hillsboro, OR. 97123
PH: (800) 843-4481 Tech. Support
for Power Validator

International Rectifier
233 Kansas St.
El Segundo, CA 90245
PH: (310) 322-3331

IRC Inc.
PO Box 1860
Boone, NC 28607
PH: (704) 264-8861

Motorola Semiconductors
PO Box 20912
Phoenix, Arizona 85036
PH:(602) 897-5056

National Semiconductor
2900 Semiconductor Drive
Santa Clara, CA 95052-8090
PH: (800) 272-9959

Nihon Inter Electronics Corp.
Quantum Marketing Int’l, Inc.
12900 Rolling Oaks Rd.
Caliente, CA 93518
PH: (805) 867-2555

Panasonic Industrial Co.
6550 Katella Avenue
Cypress, CA 90630
PH: (714) 373-7366

Pulse Engineering
12220 World Trade Drive
San Diego, CA 92128
PH: (619) 674-8100

Sanyo Energy USA
2001 Sanyo Avenue
San Diego, CA 92173
PH: (619) 661-6620

Siliconix
Temic Semiconductors
2201 Laurelwood Road
Santa Clara, CA 95056-1595
PH: (800) 554-5565

Sumida Electric USA
5999 New Wilke Road Suite #110
Rolling Meadows, IL 60008
PH: (708) 956-0702

Xicon Capacitors
PO Box 170537
Arlington, Texas 76003
PH:(800) 628-0544

Содержание SEMICONDUCTOR RC5040

Страница 1: ...In a high volume production envi ronment such as with personal computers however a CPU voltage change requires a CPU board re design to accommo date the new voltage requirement The integrated 4 bit D...

Страница 2: ...r must be greater than 80 at high current draw and greater than 40 at low current draw Processor Voltage Identification The Pentium Pro package has four voltage identification pins VID3 VID0 that can...

Страница 3: ...cally thus opti mizing efficiency under all loads The key differences between the RC5040 and RC5042 are listed in Table 4 Table 4 RC5040 and RC5042 Differences Refer to the RC5040 Block Diagram illust...

Страница 4: ...0mV increments To guarantee stable operation under all loads a 10K pull up resistor and 0 1 F of decoupling capacitance should be connected to the VREF pin No load should be imposed on this pin Power...

Страница 5: ...ripple current flowing through the output inductor allowing the use of a larger inductor value Operation at lower fre quencies increases the amount of energy storage that the bulk output capacitors mu...

Страница 6: ...65 AP42 04 R7 10K C1 1000 F C2 C3 1000 F 1000 F C5 0 1 F DS2 1N5817 C12 1 F L1 1 3 H M1 2SK1388 M2 2SK1388 C8 C9 0 1 F 0 1 F RSENSE 8m 1500 F C13 L2 2 6 H M3 2SK1388 VREF C15 C14 1500 F 1500 F C4 0 1...

Страница 7: ...5 TO 220 JA 62 5 NDP606AL TJ 125 C 33 40 JC 1 5 Motorola VGS 5V ID 37 5A TJ 25 C 6 9 TO 263 JA 62 5 MTB75N03HDL TJ 125 C 9 3 14 D2 PAK JC 1 0 Int Rectifier VGS 5V ID 31A TJ 25 C 28 TO 220 JA 62 5 IRLZ...

Страница 8: ...re 7 illustrates how an external 12V source can be used to bias VCCQP A 47 resistor is used to limit the transient current into the VCCQP pin and a 1 F capacitor filter is used to filter the VCCQP sup...

Страница 9: ...gate charge and f is the switching frequency Efficiency POUT pIN IOUT VOUT IOUT VOUT PLOSS PLOSS PDMOSFET PDINDUCTOR PDRSENSE PDGATE PDDIODE PDTRAN PDCAP PDIC 1 PDMOSFET IOUT 2 RDS ON DutyCycle DutyCy...

Страница 10: ...rs This methodology limits the power delivered to the load during an overcurrent condition The voltage drop cre ated by the output current flowing across a sense resistor is presented to one terminal...

Страница 11: ...037 0 5 1 650 10 3 1 048A RSENSE Vth min ISC 1 TF Vth min 1 0 ILoad max 1 TF Table 7 Comparison of Sense Resistors Refer to Appendix A for Directory of component suppliers Description Motherboard Tra...

Страница 12: ...ue where R20 is the resistance at 20 C 20 0 00393 C T is the operating temperature andR is the desired value For temperature T 50 C the R change 12 Table 9 is a summary of tolerances for the Embedded...

Страница 13: ...he output voltage as the load regulation col lapses into the short circuit control mode The output voltage does not return to its nominal value until the output short cir cuit current is reduced to wi...

Страница 14: ...the Schottky diode is not being over stressed during a short circuit condition Schottky Diode Selection The application circuits of Figures 3 4 and 5 show two Schottky diodes DS1 and DS2 In synchronou...

Страница 15: ...ity output voltage ripple and load transient response The calcu lation is as follows where V is the maximum voltage deviation due to load transients T is the reaction time of the power source and IO i...

Страница 16: ...for the MOSFETs In general noisy switching lines should be kept away from the quiet analog section of the RC5040 That is traces that connect to pins 12 and 13 HIDRV and VCCQP should be kept far away...

Страница 17: ...le and Silk Screen are presented below The actual PCAD Gerber File can be obtained from Raytheon Electronics Semicon ductor Division s Marketing Department at 415 966 7819 Figure 16 Example of Proper...

Страница 18: ...AN42 APPLICATION NOTE 18...

Страница 19: ...d at 1A increments an active load HP6060B or equivalent is suggested 6 In case of poor regulation refer to the procedures in the Troubleshooting section Troubleshooting 1 If no voltage is registered a...

Страница 20: ...overshoots then the noise may cause the converter to function improperly 9 Next look at the HIDRV pin This pin directly drives the gate of the FET It should provide a gate drive Vgs of about 5V when t...

Страница 21: ...th the supply However with the input filter design the Input Rush Current will be well within specification VID Iload A Vout V 1010 0 5 2 505 1 0 2 504 2 0 2 501 3 0 2 496 4 0 2 493 5 0 2 493 6 0 2 49...

Страница 22: ...evice Description Case Temperature C Iload 9 9A Case Temperature C Iload 12 4A Case Temperature C Iload 13 9A Q3A MOSFET K1388 57 63 56 3 Q3B MOSFET K1388 58 64 66 6 L1 Inductor Unknown 53 56 61 2 Q2...

Страница 23: ...design considerationsn and component selec tions layout guidelines and considerations guidelines for debugging and performance evaluations RC5040 RC5042 Evaluation Board Raytheon Electronics provides...

Страница 24: ...00 Fax 852 2314 0061 National Semiconductor Japan Ltd Tel 81 3 5620 6175 Fax 81 3 5620 6179 Appendix A Directory of Component Suppliers Dale Electronics Inc E Hwy 50 PO Box 180 Yankton SD 57078 0180 P...

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