ST25R3920B datasheet(40/158 Pages) STMICROELECTRONICS

tên linh kiện	ST25R3920B

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Application information

ST25R3920B

40/158

DS13890 Rev 4

The AM regulator, together with the am_filt bits, and circuitry behind, creates the reference

for the filter curve. A larger value of am_filt results in a larger time constant of the VDD_AM

regulator, and a slower signal transition. All timer names in AWS register that end with “1”

(for instance, tmodsw1) represent the timer starts at falling edge. Similarly, all timer names

that end with ‘2’ (for instance, tmodsw2) mean that the timer starts at rising edge (end of

modulation).

The typical preset values for slow, medium and fast transients in OOK and ASK can be

applied by setting as showed in the below table:

Note:

The settings must be adjusted individually with the final antenna.

Table 5. Typical preset values for slow, medium and fast transients in OOK and ASK

Slow transient

Medium transient

Fast transient

AWS Config 2 = 0xXCh

AWS Config 2 = 0xX8h

AWS Config 2 = 0xX4h

AWS time 1 = 0x01h

AWS time 3 = 0x9Ch

AWS time 3 = 0x79h

AWS time 3 = 0x57h

AWS time 4 = 0x0Ah

AWS time 4 = 0x07h

AWS time 4 = 0x06h

ST25R3920B bảng dữ liệu(PDF) 40 Page - STMicroelectronics