Samsung SCH-A310 Service Manual

Also see for SCH-A310 Series: User guide User guide User guide

6. Circuit Description6-1 Logic SectionSAMSUNG Proprietary-Contents may change without notice6-16-1-1 Power SupplyTo power on the phone, Pressing the PWR key withthe battery installed will short the V_BAT andON_SW signal. The V_DC, which is connected withV_BAT, will be turned on simultaneously, The V_PDand V_IF LDOs outputs of Regulator(U201, U322)are turned on assuming V_BAT is greater than2.85V.Pressing the PWR key( )of the keypad for a fewseconds, The V_BAT voltage is applied to theON_SW, the ON_SW signal will transition highwhen the PWR_HOLD signal is high.The low state ONO\signal will be detected by theMSM, when PWR_HOLD signal is high, to set thePWR_HOLD signal low and power off the phone.Once the PWR_HOLD signal is low all the LDOsoutput of the Regulator(U201, U322)will bepowered off after typically 60ms delay and all thelogic of the PMIC will be reset to the shutdowncondition.The V_PD output voltage of Regulator(U201) isconnected with V_MEM(used in memory),V_LCD(used in LCD), V_MSMD(used in the digitalparts of MSM).6-1-2 Inner Charging Circuit PartThe most important function of the charger shall bedone in the LTC1734(U240).When the phone attached a battery is connectedwith travel charging adapter, the inner chargingcircuit of the LTC1734(U240) will charge by theconstant fast charge current.When battery reaches regulation voltage of 4.2V(default charging voltage for Li+mode), the chargecurrent drops quickly to 0mA by the programmeddata of the LTC1734 controlled from the MSM.-Input voltage range : 4.75~8V-Charging Temperature :0°C~40°C-Charging Method : Constant Voltage/Current-Charging Current : Max 550mA-Charging Time : Standard (550mAh) 1.5 ~ 2 HrsExtended (900mAh) 3 ~ 3.5 Hrs-Charging Mode : 1. Charging - RED Lamp2. Completion -GREEN Lamp-Charging Battery Regulation Voltage1. Min 4.158V, Typical 4.2V, Max 4.242V(at T A : 0°C to +85°C)2. Min 4.137V, Typical 4.2V, Max 4.263V(at TA : -40°C to +85°C)-Over Battery Protection Voltage : Typical 5.2VUniversal Serial Bus Interface(U250)SCH-A310 supports a Universal Serial Bus(USB)interface, by the MSM 5100, to provide an efficientinterconnection between the mobile phone and aPersonal Computer(PC).The MSM 5100's USB interface is designed tocomply with the Universal Serial Bus Specification,Revision 1.1.The USB interface of SCH-A310 and can be used totransfer over-the-air data, or voice PCM samplesbetween the mobile phone and the USB host.An external USB transceiver(U250) and 48MHzcrystal oscillator(OSC110) are required to implementthe USB interface.END/