Shanghai SIMCom Wireless Solutions Limited 8PSA301 User Manual
Smart Machine Smart Decision
29
External components should be located near the USB connector.
Should be routed away from sensitive circuits and signals.
If there are test points, place them on the trace to keep branches as short as possible
If USB connector is used as the charger input, USB_VBUS node must be routed to the module using
Should be routed away from sensitive circuits and signals.
If there are test points, place them on the trace to keep branches as short as possible
If USB connector is used as the charger input, USB_VBUS node must be routed to the module using
extremely wide traces or sub planes.
Refer to the following table for the length of USB traces inside the module.
Table 17: Length of USB traces inside the module
Pin#
Net Name
Length(mm)
13
USB_DM
30.58
14
USB_DP
30.22
SDC Signal
Protect other sensitive signals/circuits from SDC corruption.
Protect SDC signals from noisy signals (clocks, SMPS, etc.).
Up to 200 MHz clock rate
50
Protect SDC signals from noisy signals (clocks, SMPS, etc.).
Up to 200 MHz clock rate
50
Ω nominal, ±10% trace impedance
CLK to DATA/CMD length matching < 1 mm
30–
30–
35 Ω termination resistor on clock lines near the module
Total routing length < 50 mm recommended
Spacing to all other signals = 2x line width
Bus capacitance < 15 pF
Refer to the following table for the length of SD traces inside the module.
Spacing to all other signals = 2x line width
Bus capacitance < 15 pF
Refer to the following table for the length of SD traces inside the module.
Table 18: Length of SD traces inside the module
Pin#
Net Name
Length(mm)
39
SD_CLK
14.24
40
SD_CMD
15.19
41
SD_DATA0
14.87
42
SD_DATA1
13.63
43
SD_DATA2
12.90
44
SD_DATA3
13.05
Audio
Analog input
4 to 5 mil trace widths; 4 to 5 mil spacing between traces
Differential route for MIC1P with GND_MIC and MIC2P with GND_MIC;
Isolate from noise sources, such as antenna, RF signals, SMPS, clocks, and other digital signals with fast
4 to 5 mil trace widths; 4 to 5 mil spacing between traces
Differential route for MIC1P with GND_MIC and MIC2P with GND_MIC;
Isolate from noise sources, such as antenna, RF signals, SMPS, clocks, and other digital signals with fast