Rf02, Oscillator control logic – Rainbow Electronics RF02 User Manual

Page 13

RF02

Oscillator control logic

3. Frequency Setting Command

bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 POR

1 0 1 0 f11

f10

A7D0h

The 12-bit parameter of the Frequency Setting Command has the value F. The value F should

be in the range of 96 and 3903. When F is out of range, the previous value is kept. The synthesizer

center frequency f

can be calculated as:

= 10 MHz * C1 * (C2 + F/4000)

The constants C1 and C2 are determined by the selected band as:

Band [MHz]

433

868

915

Note:

• For correct operation of the frequency synthesizer, the frequency and band of operation need to be

programmed before the synthesizer is started. Directly after activation of the synthesizer, the RF VCO is

calibrated to ensure proper operation in the programmed frequency band.

4. Data Rate Command

bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 POR

1 1 0 0 1 0 0 0 r7

C800h

The transmitted bit rate is determined by the 8-bit value R (bits <r7 : r0>) as:

BR = 10 MHz / 29 / (R+1)

Apart from setting custom values, the standard bit rates from 2.4 to 115.2 kbps can be approximated with

minimal error.

Note:

• PLL bandwidth should be set according the data rate. Please see the PLL Setting Command.

Tel: +86-755-86096587 Fax: +86-755-86096602 E-mail: [email protected] http://www.hoperf.com