Rtc Alarm Power Up; Power Off; Power Consumption And Operation Modes - Nokia RH-44 Series Troubleshooting - Bb

RH-44
Troubleshooting — BB
Monitoring the VBAT voltage level is done by charge control block (CHACON). MSTRX='1'
output reset signal (internal to UEM) is given to UEM's RESET block when VBAT>V
and UEM enters into reset sequence.
If VBAT is detected to fall below V
It will restart if new rising edge on VCHAR input is detected (VCHAR rising
above VCH
DET+

RTC alarm power up

If phone is in POWER_OFF mode when RTC alarm occurs, the wake up procedure begins.
After baseband is powered on, an interrupt is given to MCU. When RTC alarm occurs dur-
ing ACTIVE mode, the interrupt for MCU is generated.

Power off

The baseband switches to power off mode if any of following occurs:
• Power key is pressed
• Battery voltage is too low (VBATT < 3.2 V)
• Watchdog timer register expires
The Power down procedure is controlled by the UEM.

Power Consumption and Operation modes

The power off mode, the power (VBAT) is supplied to UEM, MIDI PA, VIBRA, LED, PA, and
PA drivers (Tomcat and Hornet).
In the sleep mode, both processors (MCU and DSP) are in stand-by mode. Sleep mode is
controlled by both processors. When SLEEPX signal is detected low by the UEM, the
phone enters SLEEP mode. VIO and VFLASH1 regulators are put into low quiescent cur-
rent mode, VCORE (dc/dc) enters PFM or LDO mode—depending on LM2612 or NCP1500
respectively—and VANA and VFLASH2 regulators are disabled. All RF regulators are dis-
abled during SLEEP mode. When SLEEPX signal is detected high by the UEM, the phone
enters ACTIVE mode and all functions are activated.
The sleep mode is exited either by the expiration of a sleep clock counter in the UEM or
by some external interrupt, generated by a charger connection, key press, headset con-
nection, etc.
In sleep mode, VCTCXO is shut down and 32 kHz sleep clock oscillator is used as refer-
ence clock for the baseband.
The average current consumption of the phone in sleep mode can vary depending mainly
on SW; however, on average is about 9 mA.
In the ACTIVE mode, the phone is in normal operation, scanning for channels, listening
Page 12
MSTR-
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Nokia Corporation
CCS Technical Documentation
during start-up charging, charging is cancelled.
Confidential
MSTR+
Issue 1 04/2003