1 copyright ? cirrus logic, inc. 2002 (all rights reserved) cirrus logic, inc. p.o. box 17847, austin, texas 78760 (512) 445 7222 fax: (512) 445 7581 http://www.cirrus.com AN214 application note cs4201/cs4202 six channel audio design 1. introduction this application note describes how to create a six channel ac '97 audio sub-system on a pc motherboard that can accommodate either the cs4201 or the cs4202 audio codec. 2. cs4201/cs4202 dual design figure 1 illustrates a circuit that accommodates both cs4201 and cs4202 codecs, and table 1 summarizes the population options. the only changes necessary are to pins 32, 33, 34, and 48. on the cs4201, pins 32-34 form the external connections to the analog 3d filter. pin 32 is tied to a0.01 f capacitor, and a 1000 pf capacitor is connected between pins 33 and 34. the cs4202 implements 3d spatialization in software, therefore filter capacitors c9 and c10 should not be populated. for cs4202 applications not using headphone sense, pin 32 should be tied to ground through a pull-down resistor for software compatibility. see the application note an215 for information on implementing the cs4202 with headphone sense. the audio driver will read the state of pin 33 on the cs4202 to detect two channel vs. six channel implementation. for six channel operation, pin 33 is tied to digital ground through a pull-down resistor. for information on two channel dual cs4201/cs4202 designs, see the application note an213. pin 48 of the cs4201 is used for s/pdif, or as the second serial data output. on the cs4202, pin 48 is a dedicated s/pdif output and the second serial data output is located on pin 34. 2.1 software audio drivers the cs4202 requires a pw6000 (or newer) windows wdm audio driver. this driver is compatible with the cs4201 and supports windows 98se, me, 2000, and xp. 3. typical application figures 2, 3, and 4 in the following schematics show a typical cs4201/cs4202 six channel audio motherboard application. codec populate don?t populate cs4201 r1, c9, c10 r4, r5, r6 cs4202 r4, r5, r6 r1, c9, c10 r1 0 populate 4201 only u2 (filt3d) gpio2 32 hpcfg 31 (flti) gpio3 33 (flto) gpio4/sdo2 34 (sdo/sdo2) spdif_out 48 (cs4201)cs4202 r5 10k populate 4202 only r4 0 populate 4202 only r6 10k populate 4202 only c9 1000pf npo populate 4201 only c10 0.01uf x7r populate 4201 only agnd dgnd dgnd spdif_out sdata2 sdata2 for 4202 six channel configuration gpio3 (pin 33) is tied to dgnd. figure 1. cs4201/cs4202 dual design jun ?02 AN214rev1
AN214 2 c30 1uf y5v r33 6.8k j5 1 2 r31 6.8k j7 4 3 5 2 1 r29 100k j6 1 2 3 4 c34 1uf y5v r27 100k j8 1 2 r26 1.5k r32 6.8k r23 6.8k c31 2700pf x7r c33 1uf y5v r24 4.7k r22 47k r30 100k c35 1uf y5v j9 4 3 5 2 1 r34 6.8k c37 1uf y5v r28 2.2k c38 1uf y5v c36 10uf elec + r25 6.8k c32 1uf y5v c29 0.1uf x7r agnd agnd agnd agnd dgnd agnd agnd +5va dgnd agnd agnd mic1 phone pc_beep cd_r cd_c cd_l line_in_r line_in_l beep in cd in mic in line in phone in figure 2. audio inputs
AN214 3 r1 0 populate 4201 only c10 0.01uf x7r populate 4201 only r5 10k populate 4202 only c5 0.1uf x7r c17 22pf npo c15 1000pf npo c16 22pf npo c11 1uf y5v u2 cs4202 (cs4201) line_out_r 36 mono_out 37 avdd2 38 hp_out_l 39 gpio1/sdout 44 hp_out_r 41 avss2 42 gpio0/lrclk 43 hp_out_c 40 (filto) gpio4/sdo2 34 (filti) gpio3 33 (filt 3d) gpio2 32 hpcfg 31 dvdd1 1 xtl_in 2 xtl_out 3 dvss1 4 sdat a_out 5 bit_clk 6 dvss2 7 sdat a_in 8 sync 10 dvdd2 9 reset# 11 pc_beep 12 phone 13 aux_l 14 aux_r 15 video_l 16 video_r 17 cd_l 18 cd_c 19 cd_r 20 mic1 21 mic2 22 line_in_l 23 line_in_r 24 avdd1 25 avss1 26 refflt 27 vrefout 28 aflt 1 29 aflt 2 30 (spdo/sdo2) spdif_out 48 eapd/sclk 47 id1# 46 id0# 45 line_out_l 35 c1 10uf elec + r4 0 populate 4202 only c12 1uf y5v c7 0.1uf x7r r3 47 c9 1000pf npo populate 4201 only c13 0.1uf x7r r6 10k populate 4202 only gnd_tie 0.050 inch c14 1000pf npo c2 0.1uf x7r c6 0.1uf x7r c3 0.1uf x7r c4 10uf elec + y1 24.576 mhz u1 mc78m05acdt out 3 gnd 2 in 1 r2 47 c8 0.1uf x7r bitclk sdat ain0 reset# sync sdat aout agnd agnd agnd dgnd +3.3vd dgnd agnd +5va dgnd dgnd +12v dgnd agnd dgnd dgnd dgnd pc_beep cd_r cd_c cd_l line_in_r line_in_l phone mic1 spdif_out hp_out_r hp_out_l hp_out_c sdat a2 lrclk sclk sdat a1 sdat a2 pci audio controller or ich controller tie at one point only under the codec ac link for 4202 six channel configuration gpio3 (pin 33) is tied to dgnd. codec pop no pop cs4201 r1,c9,c10 r4,r5,r6 cs4202 r4,r5,r6 r1,c9,c10 figure 3. cs4201 / cs4202
AN214 4 r13 560 r16 560 c25 0.1uf z5u r12 47k r11 270k r18 47k c21 1uf elec + u3 cs4334 sdata 1 dem#/sclk 2 lrck 3 mclk 4 aoutr 5 agnd 6 va+ 7 aoutl 8 c28 1uf elec + r8 10k u4 cs4334 sdata 1 dem#/sclk 2 lrck 3 mclk 4 aoutr 5 agnd 6 va+ 7 aoutl 8 j2 4 3 5 2 1 c22 1uf elec + c27 1uf elec + c18 220uf elec + r14 270k c24 10uf elec + r21 47k r15 47k c19 220uf elec + c20 0.1uf x7r r9 10k r19 560 c26 0.1uf z5u j4 4 3 5 2 1 r10 560 j1 totx-173 1 2 3 4 5 6 r17 270k j3 4 3 5 2 1 r20 270k r7 6.8k c23 1uf elec dgnd +5va agnd agnd agnd dgnd +5vd agnd agnd agnd agnd agnd agnd sdata2 sdata1 bitclk lrclk sclk spdif_out hp_out_c hp_out_l hp_out_r s/pdif out line out / headphone out surround jack cnt/lfe jack figure 4. analog and digital audio outputs
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