Circuit Description - Sony HSR-X200 Service Manual

6-1. Circuit Description

[1] Power Supply Processing System
(PW-1 Board)
1. Introduction
The power supply circuits are mainly formed by the
following blocks.
. Power supply switching:
. 12 V(HDD) power supply output
. 5 V power supply output:
. 3.3 V power supply output:
. 2.5 V power supply output:
. 12 V (AD) power supply output: IC582
2. Switching power supply control IC
IC501 (FA3641) is an 8-pin PWM switching control
IC that can directly drive the power MOSFET.
The oscillation frequency is decided by pin 1, second-
ary side feedback is provided by pin 2, controlling
output of the secondary side. Overcurrent detection is
done by pin 3 (overcurrent protection operation), and
an overvoltage protection function is established at the
pin 6 VCC lead.
When these overcurrent and overvoltage movements
begin to work, they generate latch-up movement as
circuits.
3. 12 V(HDD) Power Supply Output
12 V output (for the hard disk). Feedback from this 12
V goes to IC501, enabling PWM control.
4. 5 V Power Supply Output
5 V output. The 5 V is produced by IC531 (MD1222N),
a 32-pin surface mount SSOP DC/DC converter
(chopper control).
The DC/DC converter can set output voltage by
discretion, according to external resistance.
Input leads are pins 18~21, output leads are 11~14.
5. 3.3 V Power Supply Output
3.3 V output. The 3.3 V is produced by IC551
(MD1222N), a 32-pin surface mount SSOP DC/DC
converter (chopper control).
The DC/DC converter can set output voltage by
discretion, according to external resistance.
Input leads are pins 18~21, output leads are 11~14.
HSR-X200/X200P
Section 6
Block Diagrams
6. 2.5 V Power Supply Output
7. 12 V Power Supply Output
FET Q5010 and
control IC IC501
IC531
[2] Hard Disk Processing System
IC551
IC581 (CD-1 (DM-A, DM-B, DM-C), OP-1, OP-2, TB-1, TB-2,
TB-3 and TB-4)
1. Introduction
(1) DM-A
2.5 V output. IC581 (SI-3025LSA) is an 8-pin surface
mount IC.
Input leads are pins 1 and 3, output leads are 7 and 8.
12 V output (for the audio circuits). 12 V is produced
by the TO-220 package regulator of the 5-pin IC582
(SI-3090F).
Input leads are pins 2 and 5, output lead is pin 3.
a. Input/Output Video Filter: Q2011, 12, 13, 14, 21,
22, 23, 25, 31, 32, 33, 34, 41, 42, 43, 44, 45, 46,
48, 61, 62, 63, 65, IC202, 203, 204
Cuts frequencies above a sample frequency of the
input signal and eliminates entry of return noise.
Amplifies to match the decoder input levels.
Eliminates noise that is included in the encoder
video signal, and mixes brilliance and color
signals then outputs them. (Composite Out)
Brilliance and color signals are output separately.
(S-Out)
b. DECODER video IC215
Converts the received video signal to digital,
separates the brilliance and color signals and
makes them both 8 bit signals.
c. Audio Input/Output audio IC206, 207, 208
Adds AGC to the Line input signal and passes it to
the buffer for input to the audio A/D converter of
the ASIC.
Sound output from the ASIC D/A out is passed
through a filter and output through playback AGC.
When a microphone is connected, the sound
output goes through the microphone amplifier and
input is automatically connected to the micro-
phone side.
d. Serializer IC212
Serializes parallel digital data. Uses differential
method.
e. Deserializer IC211
Converts serial differential data to parallel.
6-1 (E)