Specifications

L506 Hardware Design

body to produce attenuation; But also to reduce the radiation and the structure of the realization of the

need to take into account. So, At the beginning of the design need to structure, ID, circuit, antenna

engineers together to evaluate the layout.

 Antenna matching circuit

If the module's radio frequency port and the antenna interface need to be transferred, the main board

circuit design, The design of microstrip line or strip line between the module RF test base and the

antenna interface between the microstrip line or the strip line by characteristic impedance 50 ohm, at

the same time, reserved double L type matching circuit; If the antenna's RF connector can be directly

stuck in the module's RF test base, can save the module of the RF port and the antenna interface

between the transfer.

5.4 EMC and ESD design advice

Users should take full account of the EMC problem caused by signal integrity and power integrity in

the design of the whole machine, In the module of the peripheral circuit layout, for power and signal

lines, etc., to maintain the spacing of 2 times line width. Can effectively reduce the coupling between

the signal, so that the signal has a clean, the return path. When the peripheral power supply circuit is

designed, the decoupling capacitor should be placed close to the module power supply pin, High

frequency high speed circuit and sensitive circuit should be far from the edge of PCB, and the layout

of the layout as far as possible to reduce the interference between each other, and the sensitive signal is

protected. The circuit or device that may interfere with the operation of the system board is designed.

This product is embedded in the system board side, design, need to pay attention to the ESD protection,

the key input and output signal interface, such as (U) SIM card interface need to be placed close to the

protection of ESD devices. In addition to the motherboard side, the user is required to design the

structure and PCB layout, ensure that the metal shield is fully grounded, and set up an unobstructed

discharge passage for the electrostatic discharge.

5.5 PCB Recommended land pattern

We recommend that users in the design of main board PCB DEF，In the middle of the 12 geothermal

solder design according to size in below figure. Recommended at 87 of peripheral signal pads to the

module with a length of 1.0 mm.Recommended PCB pads as shown in below.