对讲机方案3

6670E simplified baseband circuit R32 MICC 470 AGND R33 1M TXAF 2M 0.1U D4 R35 2.2K MICC C26 0.1U AGND COMN AGND C54 0.01U SPKP J1 1 SPKN C30 Ext SPK(3.5m) C34 0.1U 1 R48 10K 8 7 SCL 6 5 SDA DVDD 0.1U DGND JP3 1 2 VIB_Motor 1 2 3 4 DGND U2 A0 VCC WP A1 A2 SCL VSS SDA 24LC04 K7 K6 K5 K4 K3 K2 K1 1.5K 20P K0 1 2 U21 GND VDD /RESET TPS3809L30 K0 S0 DGND 3 DVDD X 4 K7 K6 K5 K4 K3 K2 K1 S7 S6 S5 S4 S3 S2 S1 U13 VB Int SPKP AUDI 0.1U C23 R29 5.6K TXOUT R28 10K Int Mic J5 EXTMIC C28 DIODE AUX R34 AGND 0.1U C46 COMP

TXII R22 160K

Pre-emp

X1 AGND

C25 0.1U 4.7K R31 C27 AGND MIC

TXIO MODI R23 1K MODO DEMI

C22 R21 20K 0.1U

C10 MODORF 22U De-emp R30 20K DEMO

SCL SDA SVDD DGND R36 560K Ext Mic(2.5m) 0.1U R37 AGND 1M

U20 S15 S15 20 S14 S14 19 S13 S13 18 S12 S12 17 16 S11 15 S11 S10 14 S10 S9 13 S9 S8 12 S8 S7 11 S7 S6 10 S6 S5 S