EVB71121 Melexis Company, EVB71121 Datasheet - Page 7

• Manufacturer Part Number: EVB71121
• Description: Evaluation Board For Mlx71121
• Manufacturer: Melexis Company

2.1
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 N
The following table shows the relationships of several internal receiver frequencies for the two input
frequency ranges.
Given IF2 = 1.8MHz and the corresponding N
the following table.
39012 71121 01
Rev. 003
300 to 470
610 to 930
300 to 470
610 to 930
f
f
RF
RF
RFSEL
Calculation of Frequency Settings
[MHz]
[MHz]
0
1
1
and N
2
f
f
are changed accordingly. (see in 1.5)
Injection
RF
RF
f
f
high-low
low-high
RF
RF
+
−
N
N
+
−
3.6MHz
7.2MHz
f
f
1
1
3
IF1
IF1
3
N
N
+
−
1
1
1
1
f
f
IF2
IF2
f
Rfmin
4(f
2(f
300
610
N
N
[MHz]
1
RF
RF
, N
1
1
(f
(f
N
N
+
+
2
RF
RF
Page 7 of 18
f
f
1
1
LO1
counter settings, above equations can be transferred into
LO1
1.8MHz
1.8MHz
3
3
−
+
+
+
1
1
f
f
IF2
IF2
f
)
)
Rfmax
)
)
470
930
[MHz]
Evaluation Board Description
f
RF
f
f
RF
RF
+
N
N
f
f
300 to 930MHz Receiver
1.8MHz
1
1
LO2
LO2
+
+
3
−
+
f
f
1
1
IF2
IF2
N
4
2
1
EVB71121
f
f
RF
RF
N
N
EVB Description
f
f
RF
2
RF
2
+
+
(N
(N
1.8MHz
1.8MHz
f
f
18
36
+
+
RO
RO
1
1
N
12
f
f
6
−
+
IF2
IF2
2
1)
1)
Jan/08