DEMO-ALM-2712 Datasheet, PDF (5/19 Pages) Broadcom Corporation. – GPS Filter-LNA-Filter Front-End Module

Vdd=+2.7V
R1*
Vsd
C3*
R2*
C1 0.1uF
L1*
C2
47pF
Vdd
RFin
RFout
Figure 2. Application Circuit
* optional, see notes below
Notes:
 The ALM-2712 can be operated with supply voltage (Vdd) from 1.5V to 2.85V. Vsd can operate from 1V to Vdd.
 The module is fully matched at the input and output RF pins. The RFinput pin is connected directly to a shunt inductor to ground. As such a DC
blocking capacitor is required if DC voltages are present. The RFoutput pin is already DC-blocked by the internal filter inside the module.
 Best noise performance is obtained using high-Q wirewound inductors. This circuit demonstrates that low noise figures are obtainable with
standard 0402 chip inductors.
 C1 and C2 are bypass capacitors for RF and low frequency stability and linearity .
 L1 and R1 isolates the demoboard from external disturbances during measurement. It is not needed in actual application. Likewise, C3 mitigate the
effect of external noise pickup on the Vsd line. This component are not required in actual operation. Minimal component operation is as shown in
the schematic on page 1.
 Bias control is achieved by either varying the Vsd voltage with/ without R2, or fixing the Vsd voltage to Vdd and adjusting R2 for the desired current.
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