Clocking scheme
In BB5, two main clocks are provided to the system: 38.4MHz RF clock produced by VCTCXO in the RF section
and 32.768kHz sleep clock produced by EM ASIC N2200 with an external crystal.
32 k Sleep Clock is always powered on after startup. Sleep clock is used by RAPU for low-power operation.
SMPS Clk is 2.4MHz clock line from RAPU to EM ASIC N2200. In deep sleep mode, when VCTCXO is off, this signal
is set to '0'-state.
CLK600. The clock source is an internal RC oscillator in EM ASIC (during the power-up sequence) or RAPU SMPS
Clk.
Bluetooth has a separate 38.4MHz TCXO clock oscillator.
Power distribution
Figure 12 Power distribution diagram
SIM interface
The phone has a SIM (Subscriber Identification Module) interface including a SIM connector. The connector
is only accessible when the battery is removed.
RM-781
System Module
Issue 1 COMPANY CONFIDENTIAL Page 5 – 9
Copyright © 2011 Nokia. All rights reserved.