Sleep Mode; Charging - Nokia RH-18 Manual

RH-18/36/38
Engine module
VR4
VR5
VR6
VR7
IPA1-2

Sleep mode

Sleep mode is entered when both MCU and DSP are in stand-by mode. Sleep is controlled
by both processors. When SLEEPX low signal is detected UEM enters SLEEP mode. VCORE,
VIO and VFLASH1 regulators are put into low quiescent current mode. All RF regulators,
except VR2, are disabled in SLEEP. When SLEEPX=1 is detected UEM 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 main oscillator (26MHz) is shut down and the 32 kHz sleep clock oscil-
lator is used as reference clock for the baseband.

Charging

Charging can be performed in parallel with any other operating mode. A BSI resistor
inside the battery pack indicates the battery type/size. The resistor value corresponds to
a specific battery capacity and technology.
The battery voltage, temperature, size and current are measured by the UEM controlled
by the charging software running in the UPP.
The charging control circuitry (CHACON) inside the UEM controls the charging current
delivered from the charger to the battery. The battery voltage rise is limited by turning
the UEM switch off when the battery voltage has reached VBATLim (programmable
charging cut-off limits 3.6V / 5.0V / 5.25V). Charging current is monitored by measuring
the voltage drop across a 220 mOhm resistor.
Page 12
Company confidential
Table 2: Regulator controls
Enabled; Disabled in sleep mode
Enabled; Disabled in sleep mode
Enabled; Disabled in sleep mode
Enabled; Disabled in sleep mode
Disabled
Nokia Corporation.
CCS Technical Documentation
Issue 1 10/03