Sanyo VPC-HD1010BK Service Manual page 6

1-3. PWA POWER CIRCUIT DESCRIPTION
1. Outline
This is the main power circuit, and is comprised of the follow-
ing blocks.
Switching controller (IC501)
Motor system power output (L5301)
Digital 3.25 V power output (L5004)
Digital and CMOS I/O 1.8 V power output (L5005)
Blue LED power output (Q5013, L5011)
Backlight power output (Q5009, L5007)
Digital 1 V power output (IC503, L5008)
CMOS analog 3 V power output (IC505)
CMOS digital 1.8 V power output (IC504, L5009)
Charge circuit (IC521)
2. Switching Controller (IC501)
This is the basic circuit which is necessary for controlling the
power supply for a PWM-type switching regulator, and is pro-
vided with seven built-in channels, only CH1 (motor system),
CH2 (digital 3.25 V), CH3 (digital 1.8 V), CH5 (blue LED) and
CH7 (backlight) are used.
Each power supply output is received, and the PWM duty is
varied so that each one is maintained at the correct voltage
setting level.
Feedback for the blue LED (CH5) and the backlight power
(CH7) is provided to the both ends voltage of registance so
that regular current can be controlled to be current that was
setting.
2-1. Short-circuit protection circuit
If output is short-circuited for the length of time determined
by the condenser which is connected to Pin (1) of IC501, all
output is turned off. To reset, momentarily set the control sig-
nal (P ON) to repeat control, or temporarily disconnect the
input power supply.
3. Motor System Power Output
BOOST 5 V and USB_5V are output. Feedback for the 5 V
output is provided to the switching controller (Pin (36) of IC501)
so that PWM control can be carried out.
4. Digital 3.25 V Power Output
VDD3 is output. Feedback for the VDD3 is provided to the
swiching controller (Pin (45) of IC501) so that PWM control
can be carried out.
5. Digital 1.8 V and CMOS 1.8 V (I/O) Power Output
VDD 1.8 and +1.8 V (I/O) are output. Feedback for the 1.8 V
is provided to the switching controller (Pin (44) of IC501) so
that PWM control to be carried out.
6. Blue LED Power Supply output
Regular current is being transmitted to blue LED. Feedback
for the both ends voltage of registance that is being positioned
to in series blue LED are provided to the switching controller
(Pin (39) of IC501) so that PWM control to be carried out.
7. Backlight Power Supply output
Regular current is being transmitted to LED for LCD back-
light. Feedback for the both ends voltage of registance that is
being positioned to in series LED are provided to the switch-
ing controller (Pin (42) of IC501) so that PWM control to be
carried out.
8. Digital 1 V Power Output
VDD 1.0 is output. Feedback for the VDD 1.0 is provided to
the switching controller (Pin (11) of IC503) so that PWM con-
trol to be carried out.
9. CMOS Analog 3 V Power Output
+3.0 V (A) is output. +3.0 V (A) is output to drop 3.0 V by
regulator IC505 from 3.25 V power output.
10. CMOS Digital 1.8 V Power Output
+1.8 V (D) is output. Feedback for the +1.8 V (D) is provided
to the switching controller (Pin (3) of IC504) so that PWM
control to be carried out.
11. Camera charging circuit
If the camera's power is turned off, power save mode and
sleep mode setting while it is connected to the AC adaptor,
the battery will be recharged. In the above condition, a CTL
signal is sent from the microprocessor and recharging starts.
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