LG KE970 Service Manual page 31

3. TECHNICAL BRIEF
SM-POWER supports the standby power-down concept of S-GOLD by temporarily switching off the
linear regulator LBB1 for the DSP during mobile standby whenever this subsystem is not used. In this
phase the ARM controller and most peripherals including parts of the on-chip SRAM are kept
powered-up with power being supplied by the other linear regulator LBB2.
SM-POWER includes a fully differential audio amplifier able to drive loads down to a nominal value of
8 Ohm for usage in hands-free phones and for ringing
- 400 mW maximum output power
- adjustable gain
- mute switch
- click and pop - protection
SM-POWER also integrates a charging function for Li-Ion, Li-Polymer batteries
- Precharge current source with two current levels
- Constant current / constant voltage charging with 3 different termination voltages
- Programable charge current limitation for use with different batteries
- Freely programable pulse charging to reduce the thermal power dissipation in the constant voltage
charging phase
- Top-off charge current sensing
SM-POWER completes the USB interface of S-GOLD
- Regulated voltage for S-GOLD USB interface including reverse current and overvoltage protection
- Switch to supply USB pull-up resistor
- Mini-host pull down resistor functionality
- Charge pump with internal switching capacitor for USB host VBUS supply voltage
SM-POWER fully supports LED and Vibra Motor functionality
- no external components needed
- driver for backlight LEDs adjustable in steps up to 140mA and with soft turn on and off by PWM
dimming
- two driver outputs for single LEDs for precharge indication and signaling with i.e. change of colour
- driver for Vibra Motor with adjustable voltages, soft startup / shutdown and current limitation
SM-POWER offers several control functions
- Power-on Reset Generator with logic state machine
- I2C bus interface
- I2C bus configurable mode control logic with ON (push-button or RTC), VCXOEN and LRF3EN
(wake-up by Bluetooth) inputs
- Programable interrupt channels to handle peripherals like SIM, MMC and USB
- Monitoring of charging functions
- Undervoltage Shut-Down
- Errorflags (volatile or non-volatile) from many power-supply functions and thermal sensor in order
to debug system
- Overtemperature Shut-Down
- Overtemperature Warning
- Support of S-GOLD standby power-down concept
- Support of S-GOLD Power-Down Pad Tristate Function
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