LG Prada KE850 Service Manual page 32

SM-POWER is a further step on the successful E-Power product line with enhanced and optimized
functionality. SM-POWER features a baseband supply concept with a DC/DC step-down converter
(SDBB) cascaded by two linear regulators (LBB1/2)
- SM-POWER's DC/DC converter makes up to 40 % reduction of battery current for smart phone
functions (e.g. organizer functions, games, MP3 decoding) possible.
- SDBB has high efficiency up to 95% and also a power save mode.
- Memory Interface is directly supported by the SDBB
- SDBB can also act as main supply voltage for E-GOLD+ or S-GOLDlite baseband devices.
- For S-GOLD two linear regulators for DSP and Core are cascaded after the SDBB.
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
- Pre-charge current source with two current levels
- Constant current / constant voltage charging with 3 different termination voltages
- Programmable charge current limitation for use with different batteries
- Freely programmable 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 over-voltage 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 pre-charge indication and signaling with i.e. change of color
- driver for Vibrator Motor with adjustable voltages, soft startup / shutdown and current limitation
3. TECHNICAL BRIEF
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