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External Regulators; Clocks; Sleep Clock; System Clock - Nokia NSD-6 Disassembly & Troubleshooting Instructions

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PAMS Technical Documentation
b) P2 – TPD17
c) P3 – TPD19
d) P4 – TPD21
e) P5 – TPD22

External regulators

There are three regulators used in addition to CCONT and PENTA. One is controlled by
CCONTs VR7 regulator output and used as a low noise power source for RF. This regulator
is 2.8V nominal and can be checked at TPD9.
The second regulator is used to power the data cable accessory, so output is enabled only
when a data cable accessory is detected. This regulator is also 2.8V nominal and can be
checked at TPD51 (shares SGND).
The third regulator is used to power the DSP portion of MAD4. It is enabled by Vbb, and
difference between the rise times of the DSP regulator and Vbb should be less than
200usec. This regulator is 2.8V nominal and can be checked on pin 1, 30, or 115 of the
MAD4 ASIC. (This component is most likely stuffed if MAD4_V3 is used.)

Clocks

Sleep Clock

The 32kHz sleep clock is generated by CCONT, and can be checked at TPD31. The 32kHz
square wave will be present only after the phone is turned on. If no signal is present on
this line, check the output of the oscillator at R304. This signal should be a 2Vpp clipped
signal riding on 1.5V DC.

System Clock

The 19.2MHz system clock is generated by the VCTXO in the RF section, and then squared
in CAFE. Check TPD23, which should be approximately a 0.5V sinewave riding on 1.8V
DC. Check TPD25 (or TP14*), which should be a 2.8V squarewave. This clock is not active
during the phone's sleep mode (CLK_EN is low during sleep mode).
*Note that TP14 on NSD–3AW has been moved.

CDMA clock

The CDMA clock is 9.8MHz and is generated in CAFE with a PLL. This should be a 2.8V
square wave and can be verified at TPD24 (TP13).

Charging Circuit

The charging switch, CHAPS, is controlled by a PWM from CCCONT. This PWM can be at
1Hz or at 32Hz, with varying duty cycles, and should only be active when a charger is
detected. The frequency should be 1Hz when an ACP–7 is detected and 32Hz when an
ACP–9 is detected. To verify correct operation of CHAPS, monitor the charging current
Issue 1 04/01
Disassembly/Troubleshooting Instructions
Nokia Mobile Phones Ltd.
NSD-6
Page 11

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