Sanyo VPC-E1W Service Manual

Contents

– 11 –ASIC,memory CCD 8 bit CPUPower voltagePower OFFPlay backLCD finder3.3 V 1.2 V 1.8 V +3.4 V (A)+12 V (A), -6 V(A) 3.2 VOFF OFF 32KHzOFF OFF 32KHzON ON 4 MHzON OFF 4 MHzTable 5-2. Camera ModeNote) 4 MHz = Main clock operation, 32 kHz = Sub clock operation3. Power Supply ControlThe 8-bit microprocessor controls the power supply for the overall system.The following is a description of how the power supply is turned on and off. When the battery is attached, a regulated 3.2 V (poweroff: 2.4 V) voltage is normally input to the 8-bit microprocessor (IC301) by IC302, so that clock counting and key scanning iscarried out even when the power switch is turned off, so that the camera can start up again. When the battery is removed, the 8-bit microprocessor operates in sleep mode using the backup battery. At this time, the 8-bit microprocessor only carries out clockcounting, and waits in standby for the battery to be attached again. When a switch is operated, the 8-bit microprocessor suppliespower to the system as required.The 8-bit microprocessor first sets the P ON signal at pin (40) to high, and then turns on the DC/DC converter. After this, lowsignal is output from pin (17) so that the ASIC is set to the reset condition. After this these pins set to high, and set to activecondition. Once it is completed, the ASIC returns to the reset condition, all DC/DC converters are turned off and the power supplyto the whole system is halted.Power switch ON - Auto power OFFCAMERA