Power Off; Power Consumption And Operation Modes - Nokia RM-11 Series Troubleshooting Manual

CC Technical Documentation

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)
• Or if 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 (N603 and N602). During this mode, the current consumption on this mode is
approximately 35 uA. This is the UEM leakage current.
In sleep mode, both processors, MCU and DSP, are in stand-by mode. The mobile terminal
will go to sleep mode only when by both processors made this request. When SLEEPX
signal is detected low by the UEM, the mobile terminal 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 mobile terminal
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
connection etc.
In sleep mode, the VCTCXO (19.2 MHz Clk) is shut down and the 32 kHz sleep clock
oscillator is used as reference clock for the baseband.
The average current consumption of the mobile terminal can vary depending mainly on
the software state (e.g., slot cycle 0, 1, 2) and if the mobile terminal is working on IS95
or IS2000 for CDMA. However, on average it is about 6 mA in slot cycle 0 on IS95.
In the Active mode, the mobile terminal is in normal operation, scanning for channels,
listening to a base station, transmitting and processing information. There are several
sub-states in the active mode depending on the mobile terminal present state such as:
burst reception, burst transmission, if DSP is working etc.
In active mode, software controls the UEM RF regulators VR1A and VR1B, which can be
enabled or disabled. These regulators work with the UEM charge pump. VSIM can be
enabled or disabled and its output voltage can be programmed at 1.8 V or 3.3 V. VR2 and
VR4—VR7 can be enabled or disabled or forced into low quiescent current mode. VR3 is
always enabled in active mode and disabled during sleep mode and cannot be controlled
by software in the same way as the other regulators. VR3 only turns off if both
processors (DSP and MCU) request to be in sleep mode.
Issue 2 09/2005
©2005 Nokia Corporation
Troubleshooting - Baseband
Confidential
RM-11
Page 13