CMX994 Datasheet, PDF (47/61 Pages) CML Microcircuits – Local Oscillator

Direct Conversion Receivers
CMX994/CMX994A/CMX994E
8.3 Transmitter LO Output
The transmitter LO output is taken from the CMX994 LO source and is independently buffered or divided to
the TXLO pin. The division ratio is selected with the TXDIV0 and TXDIV1 bits in the VCO Control register ($25,
b5-b6; see section 7.11.1). The output level variation with frequency of the TXLO output is shown in Figure 27
and typical variation with temperature is shown in Figure 28 and Figure 29.
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
0
No Divider
With Divider
200
400
600
800
1000
Frequency / MHz
0
-1
-2
-3
-4
-5
-6
-7
-40
Figure 27 Tx Output Level vs. Frequency
150 MHz
450 MHz
940 MHz
-20
0
20
40
60
80
Temperature / deg C
Figure 28 Typical Tx Output Level (With Divider) vs. Temperature
 2015 CML Microsystems Plc
Page 47 of 70
D/994_A_E/1