Design Considerations - Quectel SC20 Series Hardware Design

Figure 25: Reference Circuit Design for Front Camera Interface

3.20.3. Design Considerations

Special attention should be paid to the definition of video device interfaces in schematic design.

Different video devices will have varied definitions for their corresponding connectors. Ensure the
device and the connectors are correctly connected.
MIPI are high speed signal lines, supporting maximum data rate of up to 1.5 Gbps. The differential

impedance should be controlled to 100 Ω. Additionally, it is recommended to route the traces on the
inner layer of PCB, and do not cross them with other traces. For the same video device, keep all the
MIPI traces of the same length. In order to avoid crosstalk, 1.5 times of the trace width is
recommended to be maintained among MIPI signal lines. During impedance matching, do not
connect GND on different planes to ensure impedance consistency.
It is recommended to select a low-capacitance TVS for ESD protection and the recommended

parasitic capacitance is below 1 pF.
Route MIPI traces according to the following rules:

a) The total trace length should not exceed 305 mm;
b) Control the differential impedance as 100 Ω ±10 %;
c) Control intra-lane length difference within 0.67 mm;
d) Control inter-lane length difference within 1.3 mm.
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