Figure 5-24. 700 Mhz Voltage Controlled Oscillator Schematic Diagram - Motorola HT1250-LS+ Service Manual

5-30
R607
100
L608
100nH
L609
8.2nH
C628
R608
51pF
47
L610
47nH
RX_LO
C670
68pF
TX BUFFER
5 mA current draw
C665
68pF
C668
6.8pF
R661
100
L656
4.7nH
C669
47pF

Figure 5-24. 700 MHz Voltage Controlled Oscillator Schematic Diagram

R5
4.6 V Super Filter
Supply from U201
C625
51pF
C617
R605
330
NU
C616 C615
C626
0.1uF 68pF
51pF
15K R606
R609 10
L606
390nH
Q600 C622 C621
33
BFQ67W L607
3 R610 0.1uF 68pF
18nH
1 L605
33nH
2
R611 C624
15K NU
10
TX_OUT
8
RX_OUT
12
PRESC_OUT
PRESC
7
Rx_sw
RX_SWITCH
Switched supplies for VCOs 13
Tx_sw TX_SWITCH
on this page
5V when selected
C663
AUX3_5V
0.1uF
R656
680
C664
68pF
R657
120
R658
47K L653
100nH 27nH
L654
C671
7.5pF TX_INJ
Q601
33 47pF R659 3 dBm typical
BFQ67W
R660 3 C667 10
1
2
C666
to PA
NU
L655
47nH
VSF
RX VCO
1.9 V when selected
C612
C614 C613 C611
C610
0.1uF
2.2uF
0.1uF 68pF 68pF
0.1uF
18K
C602
R601
R602
33
C620 C618
C619
0.1uF
68pF 68pF
R612 L600
100nH
33
R603
18 14
33
1
TX_IADJ
2
RX_IADJ
3
SUPER_FLTR
4
COLL_RFIN
U600 5
RX_BASE
50U54 6
RX_EMITTER
16
TX_BASE
15
TX_EMITTER
20
FLIP_IN
19
TRB_IN
17 11 9
VCO Select Line L650 R652
100nH 33
R655
0V for RX
1K
5V for TX
C662 C659
3.3pF
68pF
C661
33
100pF
R653
Q603
2 3
4 L652
AUX4
100nH
3.3pF
C660
5
270
R654
LEVEL SHIFT FOR VCO SELECT
Allows 3V logic from frac-N to control 5V logic of VCO
TX VCO
Freq Range
R600
819.35 to 837.35 MHz
12K
Rx_sw
.033uF
C600
C601
51pF
C603
NU
C606
C604
L601
2.7pF
3.3pF
22nH
C607 45J93
CR600
C605
1.5pF
FL600
2.7pF
L602
100nH
C609
51pF
CR601
0.1uF
1.9 V when selected
C650
Tx_sw
R650
C651
C653 .033uF R651
0.1uF 22K
68pF C652 13K
33K
C658
R662
C655
13pF
6.8pF
18nH
L651
C654
CR603
45J93 68pF
C657
FL601
NU C656
2pF
Freq Range
746 to 794 MHz
Schematic Diagrams, Overlays, and Parts Lists
VCTRL
Steering Line
2 to 11 VDC