EVB71120-315-C(2015) View Datasheet(PDF) - Melexis Microelectronic Systems

Part Name

Description

Manufacturer

EVB71120-315-C
(Rev.:2015)

300 to 930MHz Receiver Evaluation Board Description

Melexis Microelectronic Systems  

EVB71120

300 to 930MHz Receiver

Evaluation Board Description

2.1 Calculation of Frequency Settings

The receiver has two predefined receive frequency plans which can be selected by the RFSEL control pin.

Depending on the logic level of RFSEL pin the sideband selection of the second mixer and the counter

settings for N1 and N2 are changed accordingly. (see in 1.5)

RFSEL

Injection

fRFmin [MHz]

fRFmax [MHz]

N1

N2

0

high-low

300

470

4

6

1

low-high

610

930

2

12

The following table shows the relationships of several internal receiver frequencies for the two input

frequency ranges.

fRF [MHz]

300 to 470

fIF1

f RF  N1f IF2

N1 1

fLO1

N1 (f RF  f IF2 )

N1 1

fLO2

f RF  f IF2

N1 1

fRO

f RF  f IF2

N2 (N1 1)

610 to 930

f RF  N1f IF2

N1 1

N1 (f RF  f IF2 )

N1 1

f RF  f IF2

N1 1

f RF  f IF2

N2 (N1  1)

Given IF2 is selectable at either 455kHz or 10.7MHz and the corresponding N1, N2 counter settings, above

equations can be transferred into the following table.

IF2=455kHz

fRF [MHz]

300 to 470

610 to 930

fIF1

fRF  1.82M Hz

3

fRF  0.91M Hz

3

fLO1

4(fRF  0.455MHz)

3

2(fRF  0.455MHz)

3

fLO2

fRF  0.455M Hz

3

fRO

fRF  0.455M Hz

18

fRF  0.455M Hz

36

IF2=10.7MHz

fRF [MHz]

300 to 470

610 to 930

fIF1

fRF  42.8M Hz

3

fRF  21.4M Hz

3

fLO1

4(fRF 10.7MHz)

3

2(fRF  10.7MHz)

3

fLO2

fRF  10.7M Hz

3

fRO

fRF  10.7M Hz

18

fRF  10.7M Hz

36

39012 71120 01

Rev. 006

Page 7 of 18

EVB Description

Nov/15

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