About Rf Asics And Mmic Pa; General Information; Plussa Asic - Nokia NSC/W–1/3 Series Disassembly & Troubleshooting Instructions

NSC/W–1/3
Disassembly & Troubleshooting Instructions

About RF ASICs and MMIC PA

General information

The PLUSSA (N750) provides two main functions:
The receiver block consists of IF buffers, active mixers, 2–multiplier, AGC
amplifier and limiter.
The transmitter section includes a digital gain step amplifier, a divider , an
I/Q Modulator and control part for the Transmitter Power Control loop.
The PLL section is controled via the serial bus and contains both UHF and
VHF PLL and predividers.

PLUSSA ASIC

Pin # Pin name
1 TXP_pwc
2 TXA_pwc
3 INPi_tx
4 INMi_tx
5 INMq_tx
6 INPq_tx
7 GND_P1
8 LO
9 VP1
10 VOP
11 TXC_pwc
12 DET_pwc
13 TXI_pwc
14 opain_pwc
15 opaout_pwc
16 OUT_pwc
17 VCE1
18 PD
19 VSE1
20 DGND
21 OSC
22 VDD
23 GND_P2
24 U_in
25 VP2
26 VSE2
27 PD2
Page 40
1. RX/TX blocks
2. PLL
Nomi-
nal lev-
el
2.8V
2.8V TX power loop control mode
0.8V Positive I–channel input of the TX
0.8V Negative I–channel input of the TX
0.8V Positive Q–channel input of the TX
0.8V Negative Q–channel input of the TX
0
?
2.8V VHF prediv supply voltage from CCONT
2.8V Positive supply voltage for the 1st opamp in pwrcnrl
0.5–2V Power level control of the TX
? Feedback from the peak detector diode
–
– Input for the 2nd opamp in the pwr cntrl loop
Opamp output for external feedback
– Output voltage for TX–driver
~5V VHF charge pump V5V–signal from BB
?
0 Ground for VHF charge pump
0
? 19.44 MHz–signal from G850
2.8V Positive supply for digital parts
0
0dBm
2.8V Positive supply for UHF predivider
0 Negative supply for UHF charge pump
–
Technical Documentation
Description
TX power control enable
Ground
VHF VCO signal
False transmission indicator
VHF charge pump output
Digital ground
Ground for UHF predivider
UHF VCO signal from G820
UHF charge pump output
PAMS
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