Specifications

L506 Hardware Design

5 Design guideline

This chapter provides a general design of the products instruction, the user can refer to design

guidance for design, make products to achieve better performance.

5.1 General design rules and requirements

Users in the design of this product is peripheral circuit, the first to ensure the external power supply

circuit can provide enough power supply capacity, And the requirements for high speed signal lines

USB control 90 ohm + / - 10% difference impedance. For general signal interface, require the user to

us in strict accordance with the requirements of design, in line with the interface signal level matching,

in case the level of damage to the module. This product its own radio frequency index is good,

customers need to design in accordance with the requirements the mainboard side antenna circuit and

corresponding impedance control, otherwise it will affect the whole RF index.

5.2 Reference circuit

Request system board VPH_PWR side power supply ability of power supply to achieve more than 2 A,

meet the demand of modules, peak current, and the system side the power of the average current will

reach more than 0.9 A. System board side power supply cord shall ensure enough line width, and

wants to form a good return with the ground plane, moreover should increase in the power supply

circuit design the method of micro level energy storage capacitor, guarantee the instantaneous power

supply capacity, and the power supply ripple control within the 100 mv, the specific function of each

functional module can be found in the corresponding description, overall reference circuit design

please refer《L506 reference design》.

5.3 RF part design guideline

5.3.1 Early antenna design considerations

 Pre-project evaluation

The selection of the antenna position must first ensure that the antenna and the base station are kept in

the horizontal direction, this produces the highest efficiency; Secondly, try to avoid placing the switch

in the power supply or data line, chip and other devices or chips that produce electromagnetic

interference. At the same time, the position of the hand can be avoided, so as to prevent the human