TR850 Service Manual
Baseband Board Power Supply
Figure 3-10 Baseband Board Power Supply Distribution Diagram
As Figure 3-10 shows, the baseband and RF employs isolated power supply. B13V will be divided into
three paths. One path provides power for baseband circuit, the second one is provided for Tx and Rx
module after being isolated by magnetic bead, and the last one is provided for heat dissipation fan after
being isolated by the ferrite Inductor.
The digital and analog part of the baseband circuit own separate power supply.
The power supply of the digital circuit is composed of two-level switch circuit. The first level decreases
the B13V to 5V via DC/DC (U1) ; the second level switches 5V to 3.3V, 1.8V, 1.2V and etc.. which are
isolated by various magnetic beads before being supplied to the circuit modules.
The analog circuit power supply will be directly supplied to analog audio power amplification circuit after
being switched to 8V via LDO. One power path outputs 5V_DA via the low voltage LDO (U26) and
provide it for the analog power of DAC(U24, U27), and the other oupts 3.3V_A via the low voltage LDO
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Summary of Contents for TR850
Page 1: ......
Page 45: ...TR850 Service Manual 5 4 Connection 1 2 3 4 6 8 7 5 9 10 13 14 15 16 18 17 11 12 41 ...
Page 90: ...TR850 Service Manual Figure 1 Rx Module Top Board PCB View 86 ...
Page 91: ...TR850 Service Manual Figure 2 Rx Module Bottom Board PCB View 87 ...
Page 93: ...TR850 Service Manual Figure 5 Power Amplifier Module Bottom Board PCB View 89 ...
Page 94: ...TR850 Service Manual Figure 6 Baseband Mainboard Top Board PCB View 90 ...
Page 95: ...TR850 Service Manual Figure 7 Baseband Mainboard Bottom Board PCB View 91 ...
Page 97: ...TR850 Service Manual Figure 10 Power Board Top Board PCB View 93 ...
Page 114: ...TR850 Service Manual Figure 16 Baseband Mainbaord Schematic Diagram 110 ...
Page 169: ...TR850 Service Manual Figure 1 Rx module Top Board Position Mark Diagram 165 ...
Page 170: ...TR850 Service Manual Figure 2 Rx Module Buttom Board Position Mark Diagram 166 ...
Page 172: ...TR850 Service Manual Figure 5 Power Amplifier Module Buttom Position Mark Diagram 168 ...
Page 173: ...TR850 Service Manual Figure 6 Baseband Mainboard Top Board Position Mark Diagram 169 ...
Page 174: ...TR850 Service Manual Figure 7 Baseband Mainboard Buttom Board Position Mark Diagram 170 ...
Page 176: ...TR850 Service Manual Figure 10 Power Board Top Board Position Mark Diagram 172 ...
Page 193: ...TR850 Service Manual Figure 16 Baseband Mainboard Schematic Diagram 189 ...