User Guide

• Energy management control

• Supply voltage generation

• Charge control

• Digital core supply

• Current control for LED supply

Retu

The blocks that do not have special needs are included in Retu.

Retu controls for example:

• Audio block

• SIM

• FM radio

Modes of operation

The functional behavior can be divided into seven different states. Each of these states will affect the general

functionality of the phone:

• No supply

• Backup

• Power off

• Reset

• Power on

• Deep sleep

Battery and charging

Battery

• Type: BP-5M, Li-Polymer

• Capacity: 900 mAh

• BSI resistor nominal value: 75 kΩ

Battery temperature is measured on the NTC on the main board.

Figure 25 Battery BP-5M

RM-164

System module

Issue 1 COMPANY CONFIDENTIAL Page 5 –11