RF2460
Preliminary
Current Measurement
To measure only the current of the different circuitry in the evaluation board, use the following procedure.
First, replace the bias choke inductor at the output of the mixer (L3 for US-PCS) with a 1Ω resistor. The voltage across
the resistor will represent the mixer current. Terminate all SMA connections at 50Ω.
Second, follow the table below.
ICC Total
LNA Off
Mixer Preamp Off
VCC2 Off
Mixer Current
Current (mA)
25.82
18.77
14.28
10.05
7.72
VCC1
1
1
1
1
1
CONDITION
VCC2
EN
1
1
1
1
1
1
0
1
0
1
LNA Gain
1
0
0
0
0
Mix Gain
1
1
0
0
0
Therefore,
LNA (Bypass) = (Computer Simulation) =
0 mA
LNA (High Gain) =
25.82 - 18.77
=
7.05 mA
Mixer (Preamp) =
18.77 - 14.28
=
4.49 mA
Mixer =
(Measured)
=
7.70 mA
Bias =
10.05 - 7.7
=
2.35 mA
8
LO Circuitry (VCC2) =
14.28 - 10.05
=
4.23 mA
25.82 mA
8-42
Rev A7 010912