V1.00 Page 31 of 49 ICM MP CCQ GRM
S55/S57 Company Confidential © Copyright Siemens AG 12/02
6.1.3 Power Supply Operating mode:
- Power Down Mode (mobile is switched off)
In power down mode the current consumption is very low. The inputs for switch on
conditions (ON/OFF PinH2, ON/OFF2 PinJ3, VDD_CHARGE PinC3), the LPREG with
his own voltage reference and POR cells are active. All other blocks are switched off,
so the battery discharging will be kept to a minimum. This is the state when the phone
is switched off.
- Start Up Mode (user switch on, RTC switch on)
“Start Up Mode” can be initiated by ON_OFF (falling edge) or ON_OFF2 (rising edge).
In this mode a sequential start-up, of reference oscillator, voltage supervision and
regulators is controlled by digital part. In case of failure (overvoltage or time out of the
µC reaction), the ASIC shuts down.
-Trickle Charge Mode (to be able to charge the battery)
In case of a rising edge at VDD_CHARGE, the ASIC goes from power down to an
interim state. In this state, the oscillator and the reference are started. If the voltage on
VDD_CHARGE is below the charger detection threshold, the ASIC shuts off. If the
voltage on VDD_CHARGE is high enough the signal EXT_PWR is going to H and the
power up continues. Depending on the voltage of the battery an initial charging of the
battery of the circuit is immediately done. If the Trickle Charge Mode is entered with a
very low battery, the supply for the ASIC itself is generated from the internal VDDREF
regulator. If a failure is detected (overvoltage), the ASIC is switched off.
- Normal Mode (following Start Up Mode or Trickle Charge Mode)
The normal mode is the situation, where the startup has been finished and the ASIC
starts the external µC by changing the signal RESETN from low to high.
Mode: a) Active Mode with full capabilities of all blocks
b) Sleep Mode with reduced capabilities of some blocks and some even not
available at all.
-Active Mode (submode of Normal Mode)
In this mode, the µC controls the charging block and most of the failure cases. The
ASIC can be controlled by the TWI interface, interrupt request can be sent by the
ASIC. Furthermore, the voltages are supervised ( in case of failure the µC will be
informed). In case of watchdog failure, overvoltage or power on request, the ASIC will
be switched off immediately. The mono and the stereo block can be switched on in
active mode.
-Sleep Mode (submode of Normal Mode)
Intention of the mode is to have a limited set of functions available with a reduced
current consumption. A low level at the pin SLEEP1_N will switch from Active Mode to
Sleep Mode. In Sleep Mode all charging functions and supply overvoltage detection
are switched off. LDO undervoltage detection, clock and reference voltages are active.
LDOs are working in low current mode. The battery voltage comparators are available,
the audio block can be switched on.
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