Sharp GX20 Service Manual - Page 126

GX20 CONFIDENTIAL 4321 567 8 C993 0.01 A KEY PWB-B(2/2) RECEPTION SIGNAL TRANSMISSION SIGNAL BS0 G BS BS0 BS1 BS2 GSM TX RX LOW LOW LOW LOW HIGH LOW TX HIGH LOW HIGH DCS RX HIGH LOW LOW PCS TX HIGH HIGH HIGH RX HIGH HIGH LOW B 5-29 (1-D) BS1 G BS2 G 5-23 (11-G) BATT G 5-28 (6-A) G VTXVCO C889 2.2 VTXVCO C 5-28 (6-A) VRF G VRF +B 4321 567 8 17 , 20, 29 IC992 TC7W00FK LOGIC +B 15 , 18 , 27 16 , 19 , 28 +B +B IC993 NL27WZ08 LOGIC R886 10K +B RAMPDAC 5-29 (8-E) G D R887 100K 87 R871 47 C871 100P(CH) C860 22P(C R872 33 ITXN G ITXP QTXN QTXP G G G 5-27 (8-G) E QRXN G QRXP IRXP G G IRXN G 5-26 (6-G) G VTCXO G 28 27 26 25 24 23 22 21 20 19 18 17 16 15 C921 0.01 R901 10 10 9 L861 FERRITE BEADS C873 0.001 C861 C872 0.012 R941 C941 +B 10 0.1 R942 10 C924 220P(CH) C923 220P(CH) C922 0.01 VCO8 +B GSM DCS PCS L90 8.2n 1 2 3 4 5 6 7 8 9 10 11 12 13 14 42 41 40 39 38 37 36 35 34 33 32 31 30 29 VSYNTH F SYNTHEN 5-29 (11-E) G C943 0.01 C942 0.1 R944 13 14 12 11 4.7K L972 C901 0.01 L902 8.2n G TCXOOUT 5-29 (8-D) G 5-29 (11-E) G SYNTHCLK AFCDAC 5-29 (8-E) G C954 R953 0.1 10 +B L951 FERRITE BEADS FERRITE BEADS C944 C945 6 L973 FERRITE BEADS 0.0018 270P C952 (CH) 4 L974 100P OUTPUT 4 Vcc 3 1 Vcont 2 TCX951 GND FERRITE BEADS (CH) C946 0.01 5 44 43 26MHz TCXO C975 150P R973 45 46 47 48 49 50 51 IC901 HD155148TF RF 52 53 54 55 56 C905 0.01 L903 2.7n L904 2.7n L905 2.2n (CH) 3.3K C982 0.01 R905 10 C977 0.01 C947 22P(CH) L971 FERRITE BEADS C955 0.1 R972 C980 C981 R974 1.5K 0.0022 0.0022 L90 SYNTHDATA 5-29 (11-E) G C971 4.7K C974 C973 C976 0.001 0.0082 0.01 2.2n +B NC C978 3P(CH) VCO971 0.1 +B Pin3 321 654 GSM Rx(~50CH) LOW Tx,Rx(51CH~) HIGH 4 VCO971 RF VCO 8 FL971 BALUM DCS PCS LOW HIGH 5 67 123 C979 H 3P(CH) NOTES ON SCHEMATIC DIAGRAM can be found on page 5-1. 1 2 3 4 5 6 Figure 25 SCHEMATIC DIAGRAM (23/24) 5 - 30 C902 C911