Specifications

AN93
184 Rev. 0.9
Figure 48. Verify Prototype Si3008 Failure
Figure 49. Si3008 Typical Voltages
Figure 50. Si3008 In-Circuit Resistance to IGND (Si3008 Pin 9)
To
Phone
Line
Host
Controller
Host
UART
Si24xx Si3008 Discretes
RS232
Transceiver
Si24xx Si3008 Discretes
EVB
 Connect the prototype ground to the EVB ground
 Lift prototype and EVB C1 and C2 to decouple the line side from the DSP side. Repeat this on the evaluation board.
 Connect prototype system C1 and C2 to the Si3008 pad of EVB C1 and C2
 Connect the phone line to the RJ11 jack on the EVB
 Run the prototype system software to attempt a modem connection
C2
C1
C2
C1
Prototype System
On-Hook
0.54 V
1.0 V
2.3 V
0.88 V
C1B
CID
VREG
C2B
0.04 V
0.52 V
0.06 V
0.05 V
DCT2
VREG2
QE2
DCT3
Voltages measured with respect to IGND (Si3008 pin 9)
Off-Hook
N/A
1.0 V
2.3 V
N/A
C1B
CID
VREG
C2B
1.1 V
1.7 V
2.3 V
3.0 V
Rx
QE
QB
DCT
Resistance measured with power and phone line removed
2.7 MΩ
1.6 MΩ
480 kΩ
C1B
CID
VREG
C2B
180 k
Ω
Rx
QE
QB
DCT
2.7 MΩ
2.6 MΩ
1.4 MΩ
1.4 MΩ