Rtc Alarm Power Up; Power Off; Power Consumption And Operation Modes - Nokia RH-27 Series Technical Documentation Manual

CCS Technical Documentation
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>VMSTR+
and UEM enters into reset sequence.
If VBAT is detected to fall below VMSTR- during start-up charging, charging is cancelled.
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, a wake-up procedure occurs.
After baseband is powered ON, an interrupt is given to MCU. When RTC alarm occurs
during ACTIVE mode, an interrupt to MCU is generated.

Power Off

The Baseband switches into power off mode if any of following statements is true
• 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

During power off mode, power (VBAT) is supplied to UEM, BUZZER, VIBRA, LED, PA and
PA drivers (Tomcat and Hornet). During this mode, the current consumption on this mode
is approximately 35uA. This is the UEM leakage current.
In sleep mode, both processors, MCU and DSP, are in stand-by mode. Phone will go to
sleep mode only when by both processors made this request. When SLEEPX signal is
detected low by the UEM, the phone enters SLEEP mode. VIO and VFLASH1 regulators are
put into low quiescent current mode, VCORE enters LDO mode and VANA and VFLASH2
regulators are disabled. All RF regulators are disabled 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, the VCTCXO (19.2MHz Clk) is shut down and the 32 kHz sleep clock oscil-
lator is used as reference clock for the baseband.
The average current consumption of the phone can vary depending mainly on SW state
like slot cycle 0, 1, or 2 and if the phone is working on IS95 or IS2000 for CDMA; how-
ever, on average is about 6 mA in slot cycle 0 on IS95.
Issue 1 11/2003 Confidential
©2003 Nokia Corporation
Troubleshooting - Baseband
RH-27
Page 9