cm8501aseval d emo b oard l ayout g uide 2002/08/05 preliminary rev. 1 champion microelectronic corporation page 1 cm8501aseval 1.5a bus terminator demo board layout guide psop 8 rev: b
cm8501aseval d emo b oard l ayout g uide 2002/08/05 preliminary rev. 1 champion microelectronic corporation page 2 application circuit c2 105 jp3 1 2 3 l1 3.3uh note: u1 cm8501 2 1 3 4 5 6 7 8 vccq vcc agnd sd fb pgnd vl vdd j1 pwr/in 1 2 r1 100k 2 1 jp3---->useing internal reference source(pin 1, 2 short) vdd r5 0 2 1 c6 220uf/6.3v tp1 bnc 1 2 3 4 5 u2 cm-431 1 3 2 j2 vtt 1 2 1.5a ddr bus terminator demo board circuit d1 sk12 c5 104 r3 100k 2 1 vcc c8 10uf/6.3v jp3---->useing external reference source(pin 2,3 short) r2 1k 2 1 r4 1k 2 1 c3 470 r6 5r1 2 1 vdd vcc c4 105 jp1 jumper c7 104 jp4 on/off sw jp2 jumper d2 sk12 j3 vref-out 1 2 c1 100uf/6.3v (schematic of cm8501aseval)
cm8501aseval d emo b oard l ayout g uide 2002/08/05 preliminary rev. 1 champion microelectronic corporation page 3 cm8501aseval part list item q?ty description package size designator material manufacturer resistors 1 1 0 , 1/8w 5% 0805 2*1.2 r5 carbon film resistor 2 1 5.1 , 1/8w 5% 0805 2*1.2 r6 carbon film resistor 3 2 1k , 1/8w 5% 0805 2*1.2 r4 (option) , r2 carbon film resistor 4 2 100k , 1 /8w 5% 0805 2*1.2 r1, r3 carbon film resistor capacitors 5 2 104pf/ 16v +80 ~ -20% 0805 2*1.2 c5, c7 y5v dielectric capacitor 6 2 105pf/ 16v +80 ~ -20% 1206 3.2*1.6 c2, c4 y5v dielectric capacitor 7 1 10uf/ 6.3v 10% smt-b 137*110 c8 (option) tantalum capacitor 8 1 220uf/ 6.3v 10% smt-d 287*169 c6 tantalum capacitor 9 1 100uf/ 6.3v 10% smt-d 287*169 c1 tantalum capacitor 10. 1 470pf/16v 10% 0805 2*1.2 c3 x7r dielectric capacitor magnetics 11 1 3.3uh 2a inductor smd 5*4 l1 nickel-zinc konnect electronic corp. ic?s 12 1 cm8501 sop8 sop 8 u1 champion microelectronic corp. 13 1 cm431 to-92 u2 (option) champion microelectronic corp. connectors 14 1 2-pin molex 2.54 j1 15 3 2-pin jumper pin header 2.54 jp1, jp2,jp4,j2,j3 16 1 3-pin jumper pin header 2.54 jp3 17 1 bnc tp1 diode 18 2 sk12 sma d1, d2 konnect electronic corp. tel : (02)2698-8277 fax : (02)2698-8278
cm8501aseval d emo b oard l ayout g uide 2002/08/05 preliminary rev. 1 champion microelectronic corporation page 4 cm8501aseval pcb layout cm8501aseval pcb layout
cm8501aseval d emo b oard l ayout g uide 2002/08/05 preliminary rev. 1 champion microelectronic corporation page 5 psop-08 thermal gnd pad layout multi-layer psop-08 bottom gnd pad package layout gnd pad package solder mask gnd pad package 2.34 x 2.92 mm 3.01 x 4.06 mm 2.4 x 3.0 mm via x 4 , 0.51 mm dia via x 5 , 0.33 mm dia psop-08 package bottom view land pattern comp side solder mask comp side
cm8501aseval d emo b oard l ayout g uide 2002/08/05 preliminary rev. 1 champion microelectronic corporation page 6 suggested psop-08 thermal gnd pad layout multi-layer to guarantee 2a sink or source current psop-08 bottom gnd pad package layout gnd pad package solder mask gnd pad package 2.34 x 2.92 mm 2.4 x 3.0 mm psop-08 package bottom view land pattern comp side solder mask comp side
cm8501aseval d emo b oard l ayout g uide 2002/08/05 preliminary rev. 1 champion microelectronic corporation page 7 important notice 1. did you run the websim(www.champion-micro.com) to find out ac, transient, and efficiency performance of cm8501. 2. did you separate the noise ground from the quiet ground. for example, the microprocessor?s power supply ground should be sep arated from the chip set ground because the microprocessor require 10 to 20 times of the chip set current. 3. separate vcc and vdd with 5~100 ohm . 4. add one or more high frequency capacitor for vcca and pvdd and each termination node which is far from vtt. 5. the bypass capacitor should be right next to the pin of the cm8501. c4 c2 6. do not put any capacitor between ground and vfb. 7. for cm8501 feedback compensation, it could be 50% less than cm8500 because the switching frequency of cm8501 is 1.2mhz and cm8500 is 600khz,
cm8501aseval d emo b oard l ayout g uide 2002/08/05 preliminary rev. 1 champion microelectronic corporation page 8 8. put the compensation network close to cm8501 because the vfb is a high impedance node which will be sensitive to the noise i f vfb is crossing some high frequency node and it would pick up the high frequency noise. 9. reduce the length of the main current loop which is from vl to inductor to vtt capacitor. 10. remember sd is the cmos input. 11. remember vccq behaves like a positive sense of a power supply. 12. remember agndsense is like a negative sense of a power supply. 13. therefore, vccq ? agndsense will represent the power supply for the memory chip set. 14. choose cm8501 for smaller size application. 15. vccq should be always greater than 2v. 16. vcc and vdd should always have the same power supply but they are separated with 100 ohm. the power supply should be greate r than 2.0 v and less than 4.0v. 17. always let application engineers of champion microelectronic corp. check your layout and review your design
cm8501aseval d emo b oard l ayout g uide 2002/08/05 preliminary rev. 1 champion microelectronic corporation page 9 package dimension 8-pin psop (ps08)
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