CMX994 Datasheet, PDF (56/61 Pages) CML Microcircuits – Local Oscillator

Direct Conversion Receivers
CMX994/CMX994A/CMX994E
Notes:
20. This is the maximum swing to guarantee meeting the third order distortion characteristics under the
specified conditions and is not the maximum limiting value. For clarity, this means that the device
has the capability to produce +/-1V on each of the differential outputs. The outputs are capable of
driving a load resistance across the differential outputs of 1kΩ. This voltage output capability
provides easy interfacing to other CML devices, like the CMX981, which has a maximum input signal
amplitude of 2.4Vp-p.
20a V_offset minimised using V_corr at minimum attenuation then with maximum baseband attenuation set
V_offset is measured, mixer RF input terminated in 50 Ohms; see also section 8.1.2.
21. Test method based on EN 300 166; including operation of selectable dividers.
22. Register $12, b2 = ‘0’.
23. This is the maximum bandwidth of the I and Q output signals with no external capacitors fitted and
with the filter calibration circuit disabled. The bandwidth of the I/Q output can be adjusted to suit
the application by use of the I/Q filters. This bandwidth can be set by using external capacitors (see
sections 6.2.2 and 6.2.3). Note that a 25kHz bandwidth on the I/Q filters supports a modulation
signal bandwidth of 50kHz.
24. Measured at 450MHz.
24a Measured with baseband attenuations settings of 30dB and above, with less attenuation
measurement is limited by the output compression point.
25. Average value of IIP2 measurements at 1MHz, 5MHz and 10MHz offsets using differential signals
on I and Q channels, measurements every 100MHz over the range 100MHz to 600MHz.
25a Average value of IIP2 measurements at 1MHz, 5MHz and 10MHz offsets using differential signals
on I and Q channels, measurements at 600MHz and every 50MHz over the range 700MHz to 950MHz
(1000 MHz for CMX994A/CMX994E).
Rx Direct Conversion Mixers
Gain
Notes
Min.
Typ.
Max.
Units
450MHz
26
–
15
–
dB(V/V)
940MHz
–
15
–
dB(V/V)
Noise Figure
450MHz
27
–
13.5
–
dB
Third Order Intercept Point (Input)
450MHz
27, 24
–
11
–
dBm
Input Frequency Range (CMX994)
15
100
–
940
MHz
Input Frequency Range (CMX994A/CMX994E)
15
100
–
1000
MHz
LO Frequency Range (before internal division)
15
200
–
2000
MHz
Input Impedance
29
–
–
–
Ω
Zero-IF Signal Bandwidth
at mixer output with CMX994 baseband
1
–
MHz
at mixer output with external baseband
29a
–
10
MHz
LO Leakage at Input
28
–
-80
–
dBm
Notes:
26. Measured from matched input source.
27. This is an indicative specification only as the parameter cannot be independently measured other
than as part of the complete Rx Path.
28. Measured at input to mixers with 100 Ohm termination.
29. For further details see section 5.2
29a. A 10MHz zero-IF signal bandwidth on the mixer I/Q output (pins IFLT1N, IFLT1P and QFLT1N,
QFLT1P) supports a modulation signal bandwidth of 20MHz. See section 8.1.7.
 2015 CML Microsystems Plc
Page 56 of 70
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