mc13853 Freescale Semiconductor, Inc, mc13853 Datasheet - Page 9

• Manufacturer Part Number: mc13853
• Description: Tri-band Low Noise Amplifiers With Bypass Switches
• Manufacturer: Freescale Semiconductor, Inc

Application Information
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Application Information
The MC13853 SiGe:C LNA is designed for applications in the 800 MHz to 2.1 GHz range. It has three
different modes: High Gain, Low Gain (Bypass) and Disabled. The IC mode is programmable through the
Gain and Enable bits. The current setting is also SPI programmable. The logic truth table is given in
Table
5.
In these application examples a balance is made between the competing RF performance characteristics of
I
, NF, gain, IP3 and return losses with unconditional stability. Conjugate matching is not used for the
CC
input or output. Instead, matching which achieves a trade-off in RF performance qualities is utilized. For
a particular application or spec requirement, the matching can be changed to achieve enhanced
performance of one parameter at the expense of other parameters.
Application information for 880, 950, 1800, 1960, and 2140 MHz are shown. Measurements are made at
a bias of V
= 2.775 V. Freq. spacing for IP3 measurements is 800 kHz for 2G and 10 MHz for 3GPP.
CC
The board loss corrections for these boards are: Input 0.16 dB, Output 0.2 dB. NF results incorporate these
corrections in order to better reflect the actual performance of the device.
Two MC13853 devices can also be used with common SPI control lines for a quad-band application, as
shown in Figure 3. In this application, LB and HB1 are used on LNA1 and HB2 is used on LNA2. In
active mode, both LNAs are active, but only one is connected in the circuit. Depending on which band is
selected in the connected LNA, the corresponding un-connected LNA which would also become active
when the SPI command is sent to the connected LNA will draw <1 mA for LB, <1.2 mA for HB1 and
<1mA for HB2 in active mode over temperature.
MC13853 Technical Data, Rev. 1.8
Freescale Semiconductor
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