Voltage Limits; Clocking Scheme - Nokia RH-47 Series Description
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Also See for RH-47 Series:
- Rf description and troubleshooting (76 pages) ,
- Disassembly & assembly instructions (22 pages)
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RH-47
7 - Baseband Description & Troubleshooting
back-up battery has sufficient charge in it.
• In PWR_OFF mode, the main battery is present and its voltage is over UEM mas-
ter reset threshold. All regulators are disabled.
• RESET mode is a synonym for start-up sequence and contains in fact several
modes. In this mode, regulators and oscillators are enabled and after they have
stabilized system reset is released and PWR_ON mode entered.
• In PWR_ON mode, SW is running and controlling the system.
• SLEEP mode is entered from PWR_ON mode when the system's activity is low
(SLEEPX controlled by SW).
• FLASHING mode is for production SW download.
Voltage limits
In the following table, the voltage limits of the system are listed. These are also control-
ling system states.:
Parameter
V
MSTR+
V
MSTR-
V
COFF+
V
COFF-
V_BU
COFF+
V_BU
COFF-
SW
COFF
The master reset threshold controls the internal reset of the UEM. If battery voltage is
above V
, UEM's charging control logic is alive. In addition, RTC is active and supplied
MSTR
from the main battery. Above V
this may not succeed due to voltage drops during start-up. SW can also consider battery
voltage too low for operation and power down the system.
Clocking scheme
A 26 MHz VCXO is used as system clock generator in GSM. During the system start-up,
UEM RC-oscillators generate timing for state machines. All clock signals of the engine
are illustrated in following figure.
Bluetooth uses a 26 MHz clock.
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Description
Master reset threshold (rising)
Master reset threshold (falling)
Hardware cutoff (rising)
Hardware cutoff (falling)
Back-up battery cutoff (rising)
Back-up battery cutoff (falling)
SW cutoff limit (> regulator drop-out limit) MIN!
UEM allows the system to be powered on although
MSTR
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Nokia Customer Care
Value
2.1 V (typ.)
1.9 V (typ.)
3.1 V (typ.)
2.8 V (typ.)
2.1 V (typ.)
2.0 V (typ.)
3.4 V SW changeable
Issue 1 05/04
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Troubleshooting
