Sanyo VPC-Z380, Руководство по обслуживанию

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1-3. PW1 POWER CIRCUIT DESCRIPTION
1. Outline
This is the main power circuit, and is comprised of the follow-
ing blocks.
Switching controller (IC501)
Digital 5 V and analog system power output (Q5001, T5001)
Digital 3.5 V system power supply (Q5007)
Digital 2.6 V system power output (IC503)
LCD system power supply (Q5008, T5002)
Backlight power supply output (Q5011, T5003)
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 four built-in channels, only CH1 (digital 5 V, analog
system), CH3 (LCD system), CH2 (digital 3.5 V) and CH4
(backlight) are used. Feedback from 5 V (D) (CH1), 3.2 V (D)
(CH2) , 5.0 V (L) (CH3) and 7.7 V (L) (CH4) power supply
outputs are received, and the PWM duty is varied so that
each one is maintained at the correct voltage setting level.
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 (17) of IC501, all
output is turned off. The control signal (P ON, P(A) ON and
LCD ON) are recontrolled to restore output.
3. Digital 5 V and Analog System Power Output
5 V (D) , 13 V (A), -7.0 V (A) and 5 V (A) are output. Feed-
back for the 5 V (D) is provided to the switching controller
(Pins (28) and (29) of IC501) so that PWM control can be
carried out.
4. Digital 3.5 V System Power Output
3.5 V (D) is output. Feedback is provided to the swiching con-
troller (Pin (25) and (26) of IC501) so that PWM control can
be carried out.
5. Digital 2.6 V Power Output
2.6 V (D) is output. 2.6 V (D) can be controled regular voltage
by series regulator IC (IC503).
6. LCD System Power Output
5 V (L) 1, 5 V (L) 2, 7.5 V (L), 13.5 V (L) and -15 V (L) are
output. Feedback for the 5 V (L) is provided to the switching
controller (Pin (11) and (12) of IC501) so that PWM control
can be carried out.
7. Backlight Power Supply output
7.7 V (L) is output. Feedback is sent to pins (7) and (8) of the
switching controller (IC501) for PWM control to be carried
out.