Power Supply Circuit - Sony MZ-E30 Service Manual

Fig. 5-1. shows an outline of the power supply circuit employed in the MZ-E30, as shown in the figure, the power supply
voltages applied to the MZ-E30 may be divided, if roughly classified, into three: 1.5V, 2.8V and 2.5V lines. 2.8V (VC) is
obtained by raising the 1.5V voltage in the step up circuit (2) and supplied to principal circuits, such as D/A converter (IC301),
including system controller (IC801) and DSP/digital servo (IC601).
A voltage of 8V obtained in the step up circuit (1) and in the charge pump circuit, moreover, is supplied to the servo driver
(IC551) and 2.5V to the RF amplifier (IC501) and to the optical block.
To save the electric power, the MZ-E30 has the step up circuits stop operating according to the sleep signal which the
system controller will output if the STOP mode should last for about 10 seconds (which varies with an optical block position
and/or with a mode). As a result, the power will also stop being supplied to each component. To startup, on the other hand, a
wakeup circuit will start up when a operation button located in the remote commander or in the unit is pressed. This will cause
the step up circuit to start operating so that the power is supplied to each component. In addition, this power-saving feature
also interlocks with the ON/OFF operations of the disc door opening/closing detector switch. The power supply then enters the
wakeup (startup) or sleep (standby) mode immediately.

5. POWER SUPPLY CIRCUIT

IC901
IC901
STEP UP
CIRCUIT(1)
1.5[V]
IC551
STEP UP
CIRCUIT(2)
IC551
IC901
DC-DC CONVERTER
SLEEP SIGNAL
SW
Fig. 5-1. Outline of Power Supply Circuit
— 15 —
1.5[V]
SERVO DRIVER(IC551)
HEADPHONE AMP(IC302)
8[V]
CHARGE
SERVO DRIVER(IC551)
PUMP
SYSTEM CONTROLLER(IC801)
DSP/DIGITAL SERVO(IC601)
2.8[V](VC)
D/A CONVERTER(IC301)
HEADPHONE AMP(IC302)
RF AMP(IC501)
2.5[V]
2.5[V]
OPTICAL BLOCK
REG
RF AMP(IC501)
from
SYSTEM CONTROLLER (IC801)