JVC RX-D Series Installation guide

TRAINING BOOK
FOR DIGITAL AMPLIFIER RECEIVER RX-D… SERIES
By JSCA ENGINEERING DEPARTMENT JUNE 2006
Second Edit November 2006

CONTENT
• OVERALL
• POWER SUPPLY
• POWER PROTECTION
• DIGITAL AMPLIFIER
• AUDIO DIGITAL PROCESS
• VIDEO DIGITAL PROCESS & HDMI *
• USB WIRE OR WIRELESS**
* THESE FEATURES APPLY TO RX-D401//402/701/702 ONLY.
** WIRELESS APPLIES TO RX-D301/302/701/702 ONLY.

OVERALL BLOCK DIAGRAM
Signal Flow and DC Power Supply
*
IN
=DIGITAL SIGNAL =ANALOG SIGNAL
DVD A. Multi

OVERALL BLOCK DIAGRAM note
•A AUDIO means Analog audio, D-OUT means Digital audio output.
• The HDMI outputs video only, even when the HDMI input has both
video & audio data. In the future models, the HDMI will output both A
& V data.
• The digital audio output is not available on models RX-D201/202.
The output format is the same as the digital input signal; other audio
input signals (including HDMI & USB) cannot go through the
DIGITAL OUT.
• The front left & right speaker out audio is applied to headphones.
The CPU will turn off the 7 speaker relays after it detects the
headphone jack is plugged in.
• The ‘DVD analog multi channel’ input audio bypasses the DSP
board, and goes into Master Volume Board directly.
• directly.

POWER SUPPLY BLOCK DIAGRAM
‘AMP_+/-B’ switch regulator

POWER SUPPLY 1/5
CN530-5
Q171
CN114-3
D+5V_DSP
CN114-4
R152 +12V_RY CN530-7
PWM PCB
IC201/301
IC401/801
Master Clock PCB
Regulate
PCB

POWER SUPPLY 1/5 note
•The power supply circuits for 2005 year of RX-D… series are similar. One main
difference is the ‘D+5V_HDMI’ is not in models RX-D201/202/301/302.
•There are two AC power transformers in the unit.
1. T101 for standby power: supplies D+5V and B+5V_Mi DC power for CPU IC501
and RY+9V (power ON/OFF relay circuit).
2. T102 for unit operation after power on: There are more than 15 different DC
voltages provided for unit operation after power is turned on.
•The DC voltages: +B, AMP+B, AMP-B+12V and DCDC_-B+12V all vary (along
with output volume) referenced to ground. The ‘–B’ voltage is -50v~ -62v
referenced to ground. The label ‘DCDC_-B+12V’ DC voltage means this is the
DC voltage supply to the DCDC converter circuit, the +12 DC refers to –B; if
referenced to ground, it is -38v~-50v.
•The +B and AMP+B voltages are higher in models RX-D402/702, because the
output power is higher than RX-D201/202.
•The +2.5v, DCDC_+12V, DCDC_-B+12V, AMP-B+12V, D+5V_DSP and
D+5V_HDMI are not produced in the main PCB.
•You could check all of the voltages at the indicated (underlined) locations
without any extension cable, before or after power is turned on. (See the next
page)
•Some additional DC voltages are produced in ‘Regulate PCB’ and ‘Master clock
PCB’.

POWER SUPPLY 2/5
CN114
3. D+5V_DSP
4. D+5V_HDMI *
(CN130)
* The ’D+5V_HDMI’ for models RX-D401/402/702 only.

The ‘AMP_+/-B’ switch regulator
composes three sections:
1. MOSFET switch circuit (the important parts are
Q1101/1102, D1107/1108, L1101/1102,
C1117/1118…)
2. Switch driver circuit-IC101.
3. DC-DC Converter Control Board
DC-DC
CONVERTER
CONTROL
MOSFET
DRIVE
IC101
+
MOSFET
SWITCH
Q1101/1102… _
1
3 2
AMP_B
7 CHANNEL
POWER
AMP
AMP_ +/-B
LEVEL
CONTROL
CPU IC501
SOUND
LEVEL
DETECT
POWER SUPPLY 3/5

‘AMP_ +/-B’ switch regulator-1a
The CEMF current (via D1107/8) loop
after Q1101/1102 switch off.
IC101
+B
AMP_+B
-B
AMP_-B
-B +12V
+12V
V. feedback
V.out_det.
POWER SUPPLY 3/5

Tip to measure the outputs of Q1101/1102
POWER SUPPLY 3/5

Waveform (1) at ‘AMP_+/-B’ switch regulator
The waveforms at Source and Gate of Q1101. Three periods in one cycle of
oscillation: 1.Q1101 turned on; 2. D1107 turned on by CEMF; 3. Damped LC
oscillation; Q1101 is switched off during period 2 and 3.
0 V.
AMP+B
(+30V.)
Yellow at G of Q1101 –channel 2
Blue at S of Q1101- channel 1
There is 10v At
Gate higher than
Source for
switches Q1101
on.
+B
(+60V.)
Damped oscillation
D1107 on
Q1101 on
1
2
3
POWER SUPPLY 3/5

Waveform (2) at ‘AMP_+/-B’ switch regulator
The waveforms at gate and drain of Q1102 after power is turned on.
Yellow at G of Q1102
Both channel X 10
Both channels are DC coupling
Blue at D of Q1102- channel 2
DC 0v line
-B
About
-63v
AMP
-B
About
-30v
About 10v
pulse at Gate of
Q1102 when
switch on
POWER SUPPLY 3/5

KNOW THE MOSFET
2SK3599-01MR and IRFB4212 are Enhancement-type N-channel MOSFET
• Enhancement-type MOSFET is also known as
normally off (when VGS=O, Drain current=o) MOSFET.
• N-channel MOSFET: The more positive the gate
voltage (VGS), the greater the drain current.
• There is a built in zener diode in these two kinds
of MOSFET, but it does not show in manual’s
diagram.
• The RDS (resistance between Drain and Source)
will increase when VGS drop to below 8v; and it
causes the MOSFET to get very hot and damage.
• MOSFETs have a thin layer of silicon dioxide;
this insulating layer is kept as thin as possible to
give the gate more control over drain current.
Because the insulating layer is so thin, it is easily
destroyed by excessive gate-source voltage.
-
+
+
• The transient voltages by inductive kickback and other effects may exceed the V GS
(max) rating; even handling a MOSFET may deposit enough static charge to exceed the
V GS (max) rating.
POWER SUPPLY 3/5

•If the positive drive pulse at Gate is less than 8 volts
(refer to Source), the MOSFET will get very hot to
damage. If the drive pulse is not sharp or is very noise, it
makes MOSFET very hot also.
•If the drive pulse is low & noisy, the drive IC or
peripheral parts may be defective or the power supply
may not be functioning properly.
•When handling the MOSFET, try not to touch the pins
with your fingers.
•It is preferable to use anti-static iron when soldering the
MOSFET.
•When the pair of MOSFETs are damaged, sometimes the
drive IC becomes defective too. Check the drive circuit
before replacing the MOSFETs, to prevent the power
MOSFET from shorting again.
POWER SUPPLY 3/5

‘AMP_ +/-B’ switch regulator-1b
CEMF charge path
In this circuit it, seems no current through D1107, but D1107 is high power Schottky Diode
with heat sink, If You mean with DC Volt meter but if you use Oscilloscope you can see the
negative peak is clipped. This clipping is by D1107 WHY? *DC METER CHECK
+B 70 V
ANP+B 30V (+30 V) *
_
+
Because there is a large charge current through D1107 that forced by CEMF.
POWER SUPPLY 3/5

In the relay driver circuit, always has
a diode parallel with coil, WHY?
Counter-Electromotive Force (CEMF) is a voltage developed in an inductor network
by a pulsating current or an alternating current. The voltage's polarity is at every
moment reverse that of the input voltage, therefore opposes the change of main
current flow in the circuit it is called counter-electromotive force (CEMF). The CEMF
is then given by: (the ‘–’ sign means polarity reverse)
Where iis the current, T is time and Lis the inductance (L1101) of the circuit. When
the ‘dt’ is very and very small the CEMF (voltage) will become extremely high.
If diode (D1107) is defected it can cause damage to peripheral components
What is CEMF?
POWER SUPPLY 3/5

‘AMP_ +/-B’ switch regulator-2
IC101- Drive IC for Q1101/1102
+B
AMP+B
AMP-B
-B
1
6
5
4
2
3
7
8
-B
-B_+12V
DCDC +12V
C1122
Audio
Level
detector
CPUPWM
POWER SUPPLY 3/5
VERAG
DC 42v

Bootstrap Voltage USE THE DC CLAMPER
Bootstrap Voltage
The additional
higher positive
voltage added to
the low DC voltage
Averag
e+0v
INPUT
AVERAGE
DC 30V
OUTPUT
AVERAGE DC
1. Capacitor coupling block out the input DC level.
2. The DC clamper recovers the DC level at output. *
3. The DC clamper adds DC level to the output.
Averag
e+30v
* In fact it is about +29.3v due to diode forward bias drop.
0V
Averag
e+30v 29.3V
Averag
e+42v
12v
42V
+
12v
-

• IC101 is high power MOSFET drive with
independent high and low side reference output
channels.
•The power supply for the high channel drive is
floated.
•The bootstrap voltage from VS to VB through
0.33uF capacitor C1122.
•This causes DC level at pin2-VB to be always
approximately 11v higher than pin 4-VS.
•The UV (under voltage) detector is built in the IC, if
the power supply voltage drops below the threshold
level (about 7.5-8.3 v), The IC stops output.
•If IC101 was shorted, sometimes peripheral
resistors are burnt out also.
POWER SUPPLY 3/5