AS3933 datasheet(39/64 Pages) AMSCO

Il numero della parte	AS3933

Spiegazioni elettronici	3D Low Frequency Wake-Up Receiver

PDF	64 Pages

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Produttore elettronici	AMSCO [ams AG]

Homepage	http://www.ams.com

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Page 38

ams Datasheet

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[v1-08] 2015-Sep-02

AS3933 − Detailed Description

Figure 44:

Bit Setup of the Fast Envelope for Different Symbol Rates

On one hand the fast envelope's time constant ( R3<2:0>) needs

to be adjusted to the desired symbol rate as shown in Figure 44.

However, decreasing the fast envelope's time constant also

means that more noise will be injected due to the wider band.

On the other hand, the slow envelop signal acts as an average

of the incoming data. Therefore, the bigger its time constant is,

the better will be the noise rejection. Yet, a bigger time constant

of the slow envelop (R3<5:3>) requires a longer preamble in

order to settle to the correct value. The minimum preamble

length as a function of the slow envelope's settings is given in

Figure 45.

R3<2>

R3<1>

R3<0>

Symbol Rate

[Manchester

Symbols/s]

4096

2184

1490

1130

910

762

655

512

AS3933 Scheda tecnica(PDF) 39 Page - ams AG