ALM-2412-BLKG Avago Technologies US Inc., ALM-2412-BLKG Datasheet - Page 6

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ALM-2412-BLKG

Manufacturer Part Number
ALM-2412-BLKG
Description
GPS LNA With Filter
Manufacturer
Avago Technologies US Inc.
Datasheet

Specifications of ALM-2412-BLKG

Current - Supply
20mA
Frequency
1.575GHz
Gain
13.5dB
Noise Figure
0.85dB
P1db
2.2dBm
Package / Case
12-MCOB
Rf Type
GPS
Test Frequency
1.575GHz
Voltage - Supply
3.6V
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Figure 7. Demoboard and application schematic diagram
Notes:
x The demoboard of Figure 6 is Rogers® RO4350 with typical Dk = 3.48 (@10GHz).
x L3 and the module’s internal input pre-match form the input matching network. The module has built-in DC-blocking capacitors at the input and
x This circuit demonstrates that very low noise figure is obtainable with standard 0402 chip inductors instead of high-Q wirewound inductors.
x C2 and L2 form a matching network at the output of the LNA stage, which can be tuned to optimize gain and return loss. For example, higher gain
x L1 is a choke which isolates the demoboard from external disturbances during measurement. It is not needed in actual application. Likewise, C1
x R1 is a stability-enhancing resistor.
x C9 is a DC-blocking capacitor. It is also not required in actual operation.
x Bias control is achieved by either varying the SD voltage with/ without R2, or fixing the SD voltage to Vdd and adjusting R2 for the desired current.
x For low-voltage operation such as Vdd = 1.5V or 1.0V, R2 may be omitted and SD (Vsd) connected directly to Vdd.
x The grounding regime for the ALM-2412 is critical to achieving the PCS- and Cell-Band Rejections shown in Figure 9. Please refer to the PCB Land
6
output.
can be obtained by increasing the value of C2 but at the expense of stability. Changing the value of L2 can improve the PCS rejection, but impacts
output return loss.
and C3 mitigate the effect of external noise pickup on the Vdd and SD lines respectively. These components are not required in actual operation.
Typical value for R2 is 10k Ohms for 9mA total current at Vdd = 2.85V and Vsd = +2.60V. For applications where it is more appropriate to have SD
(Vsd) connected to Vdd, an 18k Ohms resistor value for R2 is suggested (where Vdd = 2.85V).
Patterns section of this document for the exact locations of the grounding vias.
50-Ohms TL
2,4,5,6,7,9,10,11
1,4
L3
1
2
3
SD
match
Input
Vdd
C2
R2
R1
L2
3
C3
12
L1
Filter
C1
Module outline
8
C9
Z1
50-Ohms TL

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