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1-3. CP2 POWER CIRCUIT DESCRIPTION
1. Outline
This is the main power circuit, and is comprised of the follow-
ing blocks.
Switching controller (IC501)
Analog 12 V power output (Q5001, L5003)
Analog -6 V power output (Q5015, L5001)
Digital 1.2 V power output (L5006)
Digital 3.25 V power output (L5005)
5 V system power output (L5004)
Backlight power output (Q5004, L5014)
Digital 1.8 V power output (IC503, L5007)
Motor system power output (IC531, Q5301, L5301)
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 six built-in channels, only CH1 (analog 12 V power
output), CH2 (analog -6 V power outuput), CH_M (digital 3.25
V power ouput), CH_SD (digital 1.2 V output), CH_SU (5 V
system power output) and CH3 (backlight power output) are
used. Feedback from digital system 12 V (A) (CH1), -6 V (A)
(CH2), 3.25 V (D) (CH_M), 1.2 V (D) (CH_SD), 5 V (CH_SU)
and backlight (CH3) power supply outputs are received, and
the PWM duty is varied so that each one is maintained at the
correct voltage setting level.
Feedback for the backlight power (CH3) 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 internal fixing of IC501 , all output is turned off. The control
signal (P ON) are recontrolled to restore output.
3. Analog System Power Output
12 V (A) is output. Feedback for the 12 V (A) is provided to the
switching controller (Pin (3) of IC501) so that PWM control
can be carried out.
4. Analog -6 V Power Output
-6 V (A) is output. Feedback for the -6 V (A) is provided to the
swiching controller (Pin (31) of IC501) so that PWM control
can be carried out.
5. Digital 1.2 V Power Output
VDD1.2 is output. Feedback for the VDD1.2 is provided to the
switching controller (Pin (9) of IC501) so that PWM control to
be carried out.
6. Digital 3.25 V Power Output
VDD3 is output. Feedback for the VDD3 is provided to the
switching controller (Pin (13) of IC501) so that PWM control
to be carried out.
7. 5 V System Power Output
+5.0 V (D) is output. Feedback for the +5.0 V (D) is provided
to the switching controller (Pin (17) of IC501) so that PWM
control to be carried out.
8. 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 (39) of IC501) so that PWM control to be
carried out.
9. Digital 1.8 V Power Output
VDD1.8 is output. Feedback for the VDD1.8 is provided to the
switching controller (Pin (3) of IC503) so that PWM control to
be carried out.
10. Motor System Power Output
5.3 V is output. Feedback for the 5.3 V output is sent to pin (1)
of IC531 for PWM control to be carried out.
