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RF3806
Rev A3 DS070509
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.com.
Evaluation Board Schematic - UMTS2100
This eval board for low power linear operation: 21dBm<POUT<27dBm, 5 V<VCC<8V. Bias R seen above for 8V and 60mA IREF.
See biasing table for setting resistance at other supply voltages.
RF3806 Biasing Table
The resistor values shown below are for varied VCC/ICQ conditions. Biasing for higher quiescent current will give increased lin-
earity. “R_Bias”=equivalent R in line with VREF (see values on evaluation board schematic: R4, R5, R7, R8).
Max allowable IREF=60mA.
VCC
VREF
VBIAS
RBIAS (at VREF)IREF
Typical ICQ
Volt
Volt
Volt
Ohm
mA
mA
8
8
8
62
60
730
7
7
7
45
60
726
666
28.5
60
718
555
11.5
60
707
8
8
8
80.5
50
676
7
7
7
60
50
670
6
6
6
40
50
663
5
5
5
20
50
649
888
10541
623
777
80.5
41
614
666
56
41
601
555
31.5
41
584
In IREF=60mA case, calculated RBIAS was rounded up to nearest 0.5Ω.
This to keep IREF at or slightly below 60mA max.
C30
9.1 pF
R7
270
Ω
R8
270
Ω
1
2
3
4
8
7
6
5
Bias
Circuit
R4
270
Ω
R5
270
Ω
C38
10 pF
C39
1000 pF
C41
0.1
μF
VREF
50
Ω μstrip
J1
RF IN
C20
2.0 pF
C19
Open
C28
9.1 pF
C18
Open
VBIAS
C44
1000 pF
C43
10 pF
C46
0.1
μF
C45
10
μF
+
C40
10
μF
+
C27
1000 pF
L4
24 nH
C35
10 pF
C33
0.1
μF
C34
10
μF
+
R10
0
Ω
C26
Open
L2
24 nH
C10
Open
C5
1000 pF
C7
10 pF
C11
0.1
μF
C48
10 pF
C49
1000 pF
C51
0.1
μF
+
C50
10
μF
+
C6
10
μF
VCC
C16
Open
J2
RF OUT
50
Ω μstrip
C13
9.1 pF
C29
3.3 pF
C12
Open
C8
Open
C14
9.1 pF
C15
Open
L9
15 nH
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