Motorola ASTRO XTL 1500 Detailed Service Manual page 135

4-10
Table 4-6. LV Frac-N U3751 Pin Descriptions (VHF) (Continued)
Pin No.
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
June 15, 2005
Troubleshooting Procedures: VHF (136–174 MHz) Band Main Board Troubleshooting
Pin Name Description
VRO 3.0-V supply for reference oscillator warp circuitry
VMULT2 Not used
VMULT1 Not used
INDMULT Not used
— No connection
REFSEL Not used
FREFOUT Not used
AVDD 3.0-V supply (analog)
VBPASS Not used
GND Ground (analog)
XTAL1 16.8 MHz reference oscillator input
XTAL2 Not used
WARP Reference oscillator warp output
SFCAP Superfilter bypass node
SFBASE Superfilter control node for Q6759
SFOUT Superfilter output
— No connection
SFIN Superfilter supply input
— No connection
PREIN Prescalar input
GROUND Ground (prescalar)
PRE_VDD 3.0-V supply
PVREF Not used
DVDD 3.0-V supply (digital)
TEST1 Not used
TEST2 Not used
CPB2 Phase detector bias input
CPB1 Phase detector bias input
MODOUT Modulation output
CCOMP Not used
IOUT Phase detector normal mode output
GND Ground (phase detector)
IADAPT Phase detector adapt mode output
ADAPTSW Phase detector adapt switch
VCP High-voltage supply for phase detector
AUX1 Auxiliary logic output, high selects Low TX VCO
6815854H01-A