Motorola CP150TM User Manual
Page 51
6880309N62-C
June, 2005
VHF Troubleshooting Tables: Troubleshooting Table for Board and IC Signals
6-9
U201
Freq Synthesizer
24
Ref osc XTAL2
0
25
Ref osc warp output
3.00
26
Superfilter cap
4.48
27
Superfilter base (NU)
3.76
28
Superfilter output
4.52
29
NC2
0
30
Superfilter input
4.96
31
NC3
0
32
Prescaler input
1.97
33
Prescaler ground
GND
34
Prescaler Vdd
2.99
35
Prescaler Vref (NU)
1.97
36
Digital Vdd
2.99
37
TEST1 (NU)
0.01
38
TEST2 (NU)
0
39
Bias 2
3.38 (typ)
(1.34 V in TX mode)
40
Bias 1
1.50 (typ)
(3.20 V in TX mode)
41
Modulation output
3.42 (typ)
(1.62 V typ in TX mode)
42
CCOMP (NU)
0.05
43
Steering line IOUT
9.62 (typ)
Depends on frequency
44
PD ground
GND
45
Steering line IADAPT
9.62 (typ)
Depends on frequency
46
Adapt switch (NU)
0
47
Voltage from charge pump
12.8
48
AUX1 output (NU)
2.98
U251
VCO / Buffer
1
TX VCO current adjust
4.50
2
RX VCO current adjust
4.35
3
Superfiltered input
4.51
4
Collector RF in amp
4.35
5
RX VCO base
1.27
6
RX VCO emitter
0.48
7
RX switch output (NU)
0
8
RX buffered VCO output
3.36
9
GND_FLAG
GND
10
TX buffered VCO output
3.36
11
GND_BUFFERS
GND
Table 6-4. Troubleshooting Table for Board and IC Signals (Continued)
IC Designator
Pin
Pin Function
DC Voltage
Comments (Condition)