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Power supply components:

• EM ASIC N2200

• EM ASIC N2300

• EM ASIC N4200

• Application processor VCORE_APE, VIO_APE N4200

• WLAN module supplies: N5501, N5502 and N5503

• Camera supplies: N8901, N8902 and N8903

• Mini SD regulator: N4200 VMMC_APE

• Flash LED driver: D8940

All the above are powered by the main battery voltage.

Battery voltage is also used on the RF side for power amplifiers (GSM PA & WCDMA PA) and for RF ASICs.

Discrete power supplies are used to generate 2.8 V to BT, 3.0 V for the camera voltage, 1.05/1.4 V for the

application processor and 18 V for the backlight LEDs. The device supports both 1.8 V/3 V SIM cards which are

USB accessories which need power from the device are powered by N2300 / VOUT.

The external LED driver (N2310) is used in this engine implementation.

System power-up

After inserting the main battery, regulators started by HW are enabled. SW checks, if there is some reason to

keep the power on. If not, the system is set to power off state by watchdog. Power up can be caused by the

following reasons:

• Power key is pressed

• Charger is connected

• RTC alarm occurs

• MBUS wake-up

After that:

• N2200 activates sleep clock and VANA, VDRAM, VIO and VR1 regulators.

• Voltage appearing at N2200 RSTX pin is used for enabling N2300 ASIC.

• N2300 enables VCORE regulator and its internal RC-oscillator (600 kHz).

• VCTCXO regulator is set ON and RF clock (main system clock) is started to produce.

• N2200 will release PURX ~ 16ms after power up is enabled (the RF clock is then stable enough).

• Synchronizing clock (2.4MHz) for N2300 is started to be produced. After PURX is released and two rising

edges of 2.4 MHz synchronous clock have been detected in SMPSClk input N2300 is starting to use that

instead of 600kHz internal RC-oscillator.

• HW start-up procedure has been finalized and the system is up and running. Now it is possible for SW to

switch ON other needed regulators.

Clocking scheme

There are two main clocks in the system: 38.4 MHz RF clock produced by VCTCXO in RF section and 32.768 kHz

sleep clock produced by the EM ASIC N2200 with an external crystal.

RF clock is generated only when VCTCXO is powered on by the EM ASIC regulator. Regulator itself is activated

by SleepX signals from both RAP and application processor. When both CPUs are on sleep, RF clock is stopped.

RF clock is used by RAP, which provides (divided) 19.2 MHz SysClk further to the application processor. Both

RAP and the application processor have internal PLLs which then create clock signals for other peripheral

devices/interfaces like RS MMC, SIM, CCP, I2C and memories.

RA-6

System Module

Issue 1 COMPANY CONFIDENTIAL Page 6 –9