LG GX500 Service Manual page 38

GX500 Operational Description
– 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 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.
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
– 450 mW maximum output power
– adjustable gain
– mute switch SM-POWER also integrates a charging function for Li-Ion, Li-Polymer batteries
– 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
Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LG Electronics
- 9 -
39/143
3. TECHNICAL BRIEF
Revision A
LGE Internal Use Only
LGE Property