ZETEX XCD1000

ZXCD1000
HIGH FIDELITY CLASS D AUDIO AMPLIFIER SOLUTION
DESCRIPTION
The ZXCD1000 provides complete control and
modulation functions at the heart of a high efficiency
high performance Class D switching audio amplifier
solution. In combination with custom output
magnetics (ZXFN1000) and Zetex HDMOS MOSFET
devices, the ZXCD1000 provides a high performance
Class D audio amplifier with all the inherent benefits of
Class D.
applications. This lack of crossover distortion, sets the
ZXCD1000 solutions quite apart from most other
presently available low cost solutions, which in
general suffer from severe crossover distortion
problems.
FEATURES
The ZXCD1000 solution uses proprietary circuitry and
magnetic technology to realise the true benefits of
Class D without the traditional drawback of poor
distortion performance. The combination of circuit
design, magnetic component choice and layout are
essential to realising these benefits.
The ZXCD1000 reference designs give output powers
up to 50W rms with typical open loop (no feedback)
distortions of less than 0.2% THD + N over the entire
audio frequency range at 90% full output power. This
gives an extremely linear system. The addition of a
minimum amount of feedback (10dB) further reduces
distortion figures to give < 0.1 % THD + N typical at
1kHz.
•
90% efficiency
•
4 / 8 Ω drive capability
•
Noise Floor -115dB for solution
•
Flat response 20Hz - 20kHz
•
High gate drive capability ( 2200pF)
•
Very low THD + N 0.1% typical full power full
band ( for the solution)
•
Complete absence of crossover artifacts
•
OSC output available for sync in multi-channel
applications
•
Available in a 16 pin eQSOP package
APPLICATIONS
From an acoustic point of view, even more important
than the figures above, is that the residual distortion is
almost totally free of any crossover artifacts. This
allows the ZXCD1000 to be used in true hi-fi
•
Automotive audio systems
•
Home Theatre
•
Multimedia
•
Wireless speakers
•
Portable audio
•
Sub woofer systems
•
Public Address system
THD + N (%)
Distortion v Power
8Ω open loop at 1kHz.
10W
1W
5W
Output Power
The plot shows Distortion v Power into an 8Ω load at 1kHz. This plot clearly demonstrates the unequalled
performance of the Zetex solution. Typical distortion of 0.05% at 1W can be seen with better than 0.15% at 10W.
Truly world class performance.
ISSUE 1 -MARCH 2001
1
ZXCD1000
ABSOLUTE MAXIMUM RATINGS
Terminal Voltage with respect to GND
VCC
Power Dissipation
Operating Temperature Range
Storage Temperature Range
20V
1W
-40°C to 70°C
-50°C to 85°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.
These are stress ratings only, and functional operation of the device at these or any other conditions beyond
those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum
conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
TEST CONDITIONS (unless otherwise stated) VCC = 16V, TA = 25°C
SYMBOL
PARAMETER
CONDITIONS
LIMITS
MIN
V CC
Operating Voltage Range
12
I ss
Operating Quiescent
Current
V CC = 12V
V CC = 18V
V CC = 16V
F osc
Switching Frequency
C osc = 330pF
F osc(tol)
Frequency Tolerance
Vol OutA/B
UNITS
TYP
MAX
16
18
40
40
40
V
mA
mA
mA
150
200
250
kHz
C osc = 330pF
+/-25
%
Low level output voltage
No load
100
mV
Voh OutA/B
High level output voltage
No load
T Drive
Output Drive Capability
(OUT A / B Rise/Fall)
Load Capacitance
= 2200pF
5V5tol
Internal Rail Tolerance
1µF Decoupling
5.23
5.5
5.77
9VA/Btol
Internal Rail Tolerance
1µF Decoupling
8.32
8.75
9.18
V
Audio A / B
Input Impedence
1.35k
1.8k
2.3k
Ohms
Triangle
A/B
Input Impedence
1.35k
1.8k
2.3k
Ohms
7.5
V
50
ns
V
Audio A / B
Bias Level
2.95
3.1
3.25
V
Triangle
A/B
Bias Level
2.95
3.1
3.25
V
Osc A / B
Amplitude
0.89
1.05
1.2
V
ISSUE 1 - MARCH 2001
2
ZXCD1000
Pin number
Pin Name
Pin Description
1
Audio A
Audio Input for Channel A
2
Triangle A
Triangle Input for Channel A
3
Osc A
Triangle Output
4
Dist
No connection
5
C osc
External timing capacitor node (to set the switching frequency)
6
Osc B
Triangle Output (for slave ZXCD1000 in stereo application)
7
Triangle B
Triangle Input for Channel B
8
Audio B
Audio Input for Channel B
9
Gnd
Small Signal GND
10
OUT B
Channel B PWM Output to drive external Bridge MOSFETs
11
Gnd2
Power GND (for Output Drivers)
12
9VB
Internal Supply Rail (Decouple with 1µF Cap)
13
VCC
Input Supply Pin (Max = 18V)
14
9VA
Internal Supply Rail (Decouple with 1µF Cap).
15
OUT A
Channel A PWM Output to drive external Bridge MOSFETs
16
5V5
Internal Supply Rail (Decouple with 1µF Cap)
Audio A
Triangle A
Osc A
Dist
Cosc
Osc B
Triangle B
Audio B
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
5V5
Out A
9VA
VCC
9VB
Gnd2
Out B
Gnd
Figure 1
Pin Connection Diagram
ISSUE 1 -MARCH 2001
3
ZXCD1000
ZXCD1000 Class D controller IC
4
5
3
Oscillator & Ramp
Generator
Triangle B
Osc B
Osc A
Cosc
Dist
A triangular waveform is generated on chip and is
brought out at the OscA and OscB outputs. The
frequency of this is set (to ~200kHz) by an external
capacitor (Cosc) and on chip resistor. The triangular
waveform must be externally AC coupled back into the
ZXCD1000 at the TriangleA and TriangleB inputs. AC
6 7
Triangle A
coupling ensures symmetrical operation resulting in
minimal system DC offsets. TriangleA is connected to
one of the inputs of a comparator and TriangleB is
connected to one of the inputs of a second comparator.
The other inputs of these two comparators are
connected to the AudioA and AudioB inputs, which are
anti-phase signals externally derived from the audio
input. The triangular wave is an order higher in
frequency than the audio input (max 20kHz). The
outputs of the comparators toggle every time the
TriangleA/B and the (relatively slow) AudioA/B signals
cross.
A functional block diagram of the ZXCD1000 is shown
in Figure 2. The on chip series regulators drop the
external VCC supply (12V-18V) to the approximate 9V
(9VA/9VB) and 5.5V (5V5) supplies required by the
internal circuitry.
2
Osc
Buffers
Audio A
1
PWM
Comp A
8
PWM
Comp B
Audio B
O/P
Driver
PreDriver
O/P
Driver
Out A
15
Out B
10
Internal 5V5
12
16
9
11
Gnd2
14
Gnd
Internal 9V
5V5
13
9VA
9VB
VCC
PreDriver
Figure 2.
Functional Block Diagram
ISSUE 1 - MARCH 2001
4
ZXCD1000
Triangle A/B
PWM Comparator
Audio A/B
Audio A/B
O/P
Triangle A/B
Comparator O/P
(Duty Cycle = 50%)
Figure 3a.
Figure 3b.
Triangle A/B
Triangle A/B
Audio A/B
Audio A/B
O/P
Comparator O/P
(Duty Cycle = 25%)
Comparator O/P
(Duty Cycle = 75%)
Figure 3c.
Figure 3d.
Figures 3a,3b,3c and 3d
The audio input Pulse Width Modulates the comparator output.
load (with the audio information contained in the PWM
signal) via the off chip output bridge and single stage
L-C filter network.
With no audio input signal applied, the AudioA/B
inputs are biased at the mid-point of the triangular
wave, and the duty cycle at the output of the
comparators is nominally 50%. As the AudioA/B signal
ascends towards the peak level, the crossing points
with the (higher frequency) triangular wave also
ascend. The comparator monitoring these signals
exhibits a corresponding increase in output duty cycle.
Similarly, as the AudioA/B signal descends, the duty
cycle is correspondingly reduced. Thus the audio input
Pulse Width Modulates the comparator outputs. This
principle is illustrated in Figures 3a, b, c and d. The
comparator outputs are buffered and used to drive the
OutA and OutB outputs. These in turn drive the speaker
The ramp amplitude is approximately 1V. The AudioA,
AudioB, TriangleA and TriangleB inputs are internally
biased to a DC voltage of approximately VCC/5. The
mid - point DC level of the OscA and OscB triangular
outputs is around 2V. The triangular wave at the Cosc
pin traverses between about 2.7Vand 3.8V and the dist
pin exhibits a roughly square wave from about 1.4V to
2V. (The above voltages may vary in practice and are
included for guidance only).
ISSUE 1 -MARCH 2001
5
ZXCD1000
VCC
D2
R4
A1a
47k
R5
56R
Q1
ZXM64P03X
D2
C18
100n
C10
A1b
L1
ZXFN1000
68µF
AUDIO INPUT C2
22µF
C3
R1
22µF
100R
R16
U2
C8
2n2
2
C4
3
47n
R13
4
2k7
6
5
R10
10k
6
C6
R14
270pF
7
C5
47n
2k7
8
1/2 NE5532
12V REG
C7
22µF
R12
C22
C21
22µF
100n
Triangle A
5V5
Out A
15
OscA
9VA
Dist
VCC
22µF
100n
R3
100µF
Cosc
9VB
OscB
Gnd2
Triangle B
Out B
Audio B
20uH
Q2
ZXM64N03X
56R
C27
C23
C24
470n
470n
470n
R2
D1
14
47k
SPEAKER A
A4a
13
R17
12V REG
****
12
VCC
11
10
D3
R6
A1a
47k
9
Gnd
R7
C12 C14 C16
100n
R15
22µF
56R
100µF
C35
****
Q3
ZXM64P03X
SPEAKER B
D3
C19
L2
100n
2k7
U2
2k7
Audio A
16
U1
R11
2k7
100n
A4b
ZXCD1000
1
2n2
C17
C13 C15 C34
100n
2k7
C1
Gnd INPUT
D1
C11
1/2 NE5532
A1b
ZXFN1000
D4
20uH
C9
2n2
C20
A4b
100n
R8
56R
Q4
ZXM64N03X
C28
C25
C26
470n
470n
470n
78L12
C32
C33
100µF
100n
2
ISSUE 1 - MARCH 2001
C29
2200µF
VI
GND
U3
1
VCC
VO
D4
3
12V REG
C30
C31
100n
22µF
R9
47K
A4a
R17 / C35 are optional components
Figure 4
Zetex Class D 25W Mono Open Loop Solution
ZXCD1000
switching PWM signal that comes from the bridge.
Thus the lower frequency audio signal is recovered and
is available at the speakerA and speakerB outputs
across which the speaker should be connected. The
ZXFN1000 magnetics form an integral part of, and are
specially designed for, the Zetex solution.
Class D 25W Mono Open Loop (Bridge Tied
Load - BTL) Solution – Circuit Description
Proprietary circuit design and high quality magnetics
are necessary to yield the high THD performance
specified. Deviation from the Zetex recommended
solution could significantly degrade performance.
The optional components R17 and C3 form a Zobel
network. The applicability of these depends upon the
application and speaker characteristics. Suggested
values are 47nF and 10 ohms
The speaker is connected as a Bridge Tied Load (BTL).
This means that both sides of the speaker are driven
from the output bridge and therefore neither side of the
speaker connects to ground. This allows maximum
power to be delivered to the load, from a given supply
voltage. The supply voltage for this solution is
nominally 16V.
Efficiency
The following plots show the measured efficiency of
the Zetex solution at various power levels into both 4Ω
and 8Ω loads. As a comparison, typical efficiency is
plotted for a class A-B amplifier. They clearly
demonstrate the major efficiency benefits available
from the Zetex class D solution.
A schematic diagram for the solution is shown in
Figure 4. The audio input is AC coupled and applied to a
simple R-C (R1 and C1) low pass filter and a phase
splitter built around the NE5532 dual op-amp. One of
these op-amps is configured as a voltage follower and
the other as a X1 inverting amplifier. This produces in
phase and inverted signals for application to the
ZXCD1000. The op-amp outputs are AC coupled into
the ZXCD1000 Audio A and Audio B inputs via simple
R-C low pass filters (R16/C8 and R15/C9). The op-amps
are biased to a DC level of approximately 6V by R11 and
R12.
The Pulse Width Modulated (PWM) outputs, OutA and
OutB, which contain the audio information, are AC
coupled and DC restored before driving the Zetex
ZXM64P03X and ZXM64N03X PMOS and NMOS
output bridge FET’s. AC coupling is via C17, C18, C19
and C20. DC restoration is provided by the D2(A1a)/R4,
D1(A4a)/R2 and D3(A1a)/R6, D4(A4a)/R9 components.
This technique allows the output stage supply voltage
to be higher than the high level of the OutA and OutB
outputs (approximately 8.5V), whilst still supplying
almost the full output voltage swing to the gates of the
bridge FET’s (thereby ensuring good turn on). This can
be exploited to yield higher power solutions with
higher supply voltages – this is discussed later.
The resistor/diode combinations (R5/D2(A16),
R3/D1(A46), R7/D3(A16) and R8/D4(A46)) in series with
the bridge FET gates, assist in controlling the switching
of the bridge FET’s. This design minimises shoot
through currents whilst still achieving the low
distortion characteristics of the system.
The purpose of the (ZXFN1000) inductors in
conjunction with the output capacitors C23, C24, C25
and C26 is to low pass filter the high frequency
ISSUE 1 -MARCH 2001
7
ZXCD1000
Class D 25W Mono Open Loop (Bridge Tied
Load - BTL) Solution
– PCB description and Operation.
The top copper, the bottom copper and the silk screen
(top) are shown in Figures 5, 6 & 7 respectively, for the
double sided PCB implementation of the applications
circuit of Figure 4. A component listing is given in the
BOM (Bill of Materials) table. Gerber files for this
solution are available from Zetex Plc.
The board operates from a 16V (nom.) supply which
should be applied to the underside of the supply
decoupling capacitor C29. The audio input and speaker
connections should be made to the solder pads
indicated on Figure 7. The audio input should have a
maximum amplitude of approximately 1V pk-pk. For
diagnostic purposes, the speaker outputs can be
monitored single-endedly with respect to ground with
an oscilloscope (or other instrument) if desired.
However remember that the speaker is connected as a
Bridge Tied Load, therefore any results obtained in this
manner, are not valid for assessing performance. The
true performance depends upon some differential
cancellation across the speaker load. To view the
differential output across speakerA and speakerB, a
floating monitor must be used i.e. neither side of the
speaker should be grounded! For example, this can be
achieved with a two channel oscilloscope by monitoring
the speakerA and speakerB outputs, and using the invert
and add functions.
Figure 6.
Class D 25W Mono O.L. PCB Bottom Copper (Actual
Size)
The exposed pad on the underside of the ZXCD1000
eQSOP package should be soldered down to the PCB.
This in conjunction with vias and top and bottom
copper areas, functions as a heat sink.
Speaker Outputs
Audio Input
Figure 7.
Class D 25W Mono O.L. PCB
Silk Screen (Actual Size)
Plots of typical performance for the solution are
shown in the included graphs. As previously stated, a
very important feature of the Zetex solution is that the
residual distortion is almost totally free of any
crossover artifacts. This lack of crossover distortion
sets the ZXCD1000 solutions quite apart from most
other presently available low cost solutions, which in
general suffer from severe crossover distortion
problems.
Figure 5.
Class D 25W Mono O.L. PCB Top Copper (Actual Size)
ISSUE 1 - MARCH 2001
8
ZXCD1000
It is well known that this kind of distortion is particularly
unpleasant to the listener. The two scope traces clearly
show the lack of such artifacts with the Zetex solution
Other Solutions - Stereo, Closed Loop and
Higher Powers.
STEREO
It is possible to duplicate the above solution to give a 2
channel stereo solution. However if the oscillator
frequencies are not locked together, a beat can occur
which is acoustically audible. This is undesirable. A
stereo solution which avoids this problem can be
achieved by synchronising the operating frequencies
of both ZXCD1000’s class D controller IC’s, by slaving
one device from the other. This is illustrated in Figure 8.
ZXCD1000
CX1
Audio A
Triangle A
RX1
1.5k
ZETEX Class D Solution. (10W into 4Ω)
Note lack of Crossover Artifacts
Osc A
9VA
Dist
VCC
Cosc
9VB
Osc B
Gnd2
Triangle B
Out B
Audio B
RX2
5V5
Out A
MASTER
Gnd
1.5k
CX2
ZXCD1000
Audio A
Triangle A
O/C
O/C
5V5
Out A
Osc A
9VA
Dist
VCC
Cosc
9VB
Osc B
Gnd2
Triangle B
Out B
Audio B
Gnd
SLAVE
Figure 8.
Frequency sync for Stereo Apps.
Here OscA on the master is used to drive both
TriangleA and TriangleB inputs on the master. OscB on
the master is used to drive both TriangleA and
TriangleB inputs on the slave. In order to achieve the
increased drive capabilty required by the OscA/B
outputs on the master, 1.5kΩ pull down resistors are
added from these pins to ground. The slave oscillator is
disabled by connecting pin 4 (dist) to ground. Great
care must be taken when linking the triangle from the
master to the slave. Any pickup can cause slicing errors
and result in increased distortion. The best connection
method is to run two tracks, side by side, from the
master to the slave. One of these tracks would be the
triangle itself, and the other would be the direct local
ground linking the master pin9 ground to the slave pin
9 ground.
Typical Class D Solution.
Note Large Crossover Artifacts
ISSUE 1 -MARCH 2001
9
10
AUDIO INPUT
3.3µF
C21
10k
1k
1.5k
R21
R20
0.1u
C42
2.4K
R11 R43
10K
R10
10K
R9
10K
R12
220R
10k
R32
47µF
C18
10µF
R24
R31
1.5k
3
C12
2
6
5
47µF
C20
7
10k
3.9K
C2
Audio B
R18
8.2k
3
2
4.7k
R19
1
5
6
3.9k
R27
680pF
5V5
Gnd
Out B
Gnd2
9VB
VCC
9VA
Out A
16
10k
R26
10k
R25
9
10
11
12
13
14
15
C5
1µF
1µF
C4
C8
D8
1N4148
C9
1µF
47n
C40
47K
R8
47K
1N4148
1µF
R5
47K
R4
D5
1N4148
D4
1µF
C7
1µF
C6
R1
47K
D1
1N4148
Figure 9.
25W Mono with Feedback
1/2 RC4558D
7
R29
2.7k
1.6k
C22
ZXCD1000
Triangle B
OscB
Cosc
Dist
OscA
R28
8
7
6
5
4
3
Audio A
Triangle A
R16
1/2 RC4558D
2.2nF
C14
330pF
C3
1µF
1
2
IC1
15k
560R
R15
2.2nF
C13
560R
R14
C1
1µF
R22
3.9K
R23
R13
1/2 LM358D
1
1/2 LM358D
C27
22µF
R30
10R
47n
C41
430R
R41
430R
R40
1N4148
75R
R7
D7
1N4148
D6
75R
R6
75R
R3
1N4148
D3
1N4148
D2
75R
R2
VCC
VCC
ZXM64N03X
Q4
BRIDGE
O/P B
ZXM64P03X
Q2
ZXM64N03X
Q3
BRIDGE
O/P A
ZXM64P03X
Q1
C17
20µH
ZXFN1000
20uH
ZXFN1000
2200µF
20V
C10
1µF
C11
1µF
SPEAKER B
*****
R17
*****
C24
SPEAKER A
ZXCD1000
ISSUE 1 - MARCH 2001
ZXCD1000
Class D 25W Mono Bridge Tied Load
(BTL) Solution with Feedback –
Circuit Description
With the addition of feedback (hence closed loop
solution) it is possible to obtain even better THD
performance. A schematic diagram for this is shown in
Figure 9. Again proprietary circuit and special magnetic
design is necessary to yield the high THD performance
and deviation from this could significantly reduce
performance.
Much of the circuitry is the same as described for the
open loop solution. The main differences being a
consequence of using the feedback circuitry. The input
and feedback circuitry is shown separately in Figure 10
and is now described. The audio input is ac coupled and
applied to an op-amp (1/2 of RC4558D) configured as a
non–inverting amplifier with a gain of approximately
2.8. The op-amp input is tied to a DC level of
approximately VCC/2. Feedback is applied differentially
from the bridge outputs via the other half of the
RC4558D op-amp. A portion of the single ended output
from this op-amp is subtracted from the output of the
non-inverting op-amp output above. Overall negative
feedback is applied due to the polarity and connection of
the signals involved.
The audio signal from the above circuitry is applied to a
phase splitter (see Figure 11) as was done for the open
loop solution. This is built around the other LM3580 dual
op-amp. One of these op-amps is configured as a
voltage follower and the other as a X1 inverting
amplifier. This produces in phase and inverted signals
for application to the ZXCD1000 Audio A and Audio B
inputs respectively.
The output circuitry downstream of the ZXCD1000 is as
described for the open loop solution, but the
components may be slightly different (and have
different numbering).
ISSUE 1 -MARCH 2001
11
Higher Power Solutions
With some modifications the applications solutions
can be extended to give 50W or even higher output
powers. A 50W solution can be implemented with a
circuit very similar to the 25W solution. The main
differences being the supply voltage and the output
magnetics. The magnetics for 50W are necessarily
larger than required for 25W in order to handle the
higher load currents. For 50W operation the supply
voltage to the circuit is nominally 25V. However the
maximum supply voltage to the ZXCD1000 class D
controller IC is 20V, hence a voltage dropper is
required. This could be done, for example, as in the
open loop solution described previously. In addition,
for the closed loop solution, slightly modified
feedback resistor ratios are required.
The ZXCD1000 class D controller IC is inherently
capable of driving even higher power solutions, with
the appropriate external circuitry. However as stated
above the maximum supply voltage to the ZXCD1000
class D controller IC is 20V and the higher supply
voltages must therefore be dropped. Also due
consideration must be given to the ZXCD1000 output
drive levels and the characteristics of the bridge
MOSFET’s. The latter must be sufficiently enhanced
by the OutA and OutB outputs to ensure the filter and
load network is driven properly. If the gate drive of the
ZXCD1000 is too low for the chosen MOSFET then the
OUTA and OUTB signal must be buffered using an
appropriate MOSFET driver circuit. Additionally,
suitable magnetics are essential to achieve good THD
performance.
Package details
The ZXCD1000 is available in a 16 pin eQSOP
package. The exposed pad on the underside of the
package should be soldered down to an area of
copper on the PCB, to function as a heatsink. The PCB
should have plated through vias to the underside of
the board, again connecting to an area of copper.
ZXCD1000
VCC
R31
1.5k
C21
3.3µF
1/2 RC4558D
R32
Audio IN
3
1
10k
R20
2
10k
R21
C18
1.5k
47µF
R16
15k
C20
47µF
R18
8.2k
R24
220R
R19
4.7k
R26
FROM BRIDGE O/P A
(via R41/C41)
1/2 RC4558D
5
7
10k
R43
1k
6
R29
R25
FROM BRIDGE O/P B
(via R40/C40)
C22
2.7k
680pF
R27
10k
3.9k
To Phase Splitter
R28
1.6k
Figure 10.
Feedback and Input Circuitry.
VCC
R9
10k
R10
1/2 LM358D
3
R14
1
10k
To AudioA input (In Phase Signal)
560R
R11
2.4k
2
C12
R22
C13
10µF
3.9k
2.2nF
1/2 LM358D
5
Audio Signal
From Input / Feedback Circuitry
R15
7
R12
560R
10k
To AudioB input (Inverted Signal)
6
R13
R23
C14
3.9k
2.2nF
10k
Figure 11.
Phase Splitter
ISSUE 1 - MARCH 2001
12
ZXCD1000
dB
THD + N (%)
Typical performance graphs for the Zetex 25W open
loop solution are shown here for both 4 and 8Ω loads.
These graphs further demonstrate the true high fidelity
performance achieved by the Zetex solutions.
10W
5W
1W
Output Power
THD v Power into 8 at 1kHz
FFT of distortion and noise floor at 1W (8 load)
dB
dB
f(Hz)
f(Hz)
f(Hz)
FFT of distortion and noise floor at 10W (8 load)
Frequency response (8 load)
ISSUE 1 -MARCH 2001
13
dB
THD + N (%)
ZXCD1000
20W
1W
5W
10W
Output Power
THD v Power into 4 at 1kHz
FFT of distortion and noise floor at 1W (4 load)
dB
dB
f(Hz)
f(Hz)
f(Hz)
FFT of distortion and noise floor at 20W (4 load)
Frequency response (4 load)
Note roll off.
This can be corrected by using an alternative values for
output filter components.
ISSUE 1 - MARCH 2001
14
ZXCD1000
B.O.M. Table for 25W Mono Open Loop Solution
PCB
ID
Value
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
R11
R12
R13
R14
R15
R16
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
C11
C12
C13
C14
C15
C16
100R
47K
56R
47K
56R
47K
56R
56R
47K
10K
2K7
2K7
2K7
2K7
2K7
2K7
2n2 COG
22µF 10V
22µF 6V3
47n X7R
47n X7R
270pF COG
22µF 6V3
2n2 COG
2n2 COG
68µF 6V3
100n X7R
100n X7R
100n X7R
22µF 10V
22µF 16V
100µF 10V
C17
C18
C19
C20
C21
100n
100n
100n
100n
100n
X7R
X7R
X7R
X7R
X7R
Case
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD Tant B
SMD Tant B
SMD 0805
SMD 0805
SMD 0805
SMD Tant B
SMD 0805
SMD 0805
SMD Tant B
SMD 1206
SMD 0805
SMD 0805
SMD Tant B
SMD Tant B
std. Dia
6.3mm
SMD 0805
SMD 0805
SMD 0805
SMD 0805
SMD 0805
Notes
PCB
ID
Value
Case
C22
C23
C24
C25
C26
C27
C28
C29
22µF 6V3
470n
470n
470n
470n
470n
470n
2200µF 16V
C30
C31
C32
100n X7R
22µF 16V
100µF 16V
C33
C34
100n X7R
100µF 16V
U1
U2
U3
Q1
Q2
Q3
Q4
D1
ZXCD1000
NE5532
78L12
ZXM64P03X
ZXM64N03X
ZXM64P03X
ZXM64N03X
BAV70
SMD SO 8
TO92
SMD MSOP 8
SMD MSOP 8
SMD MSOP 8
SMD MSOP 8
SMD SOT23
D2
BAW56
SMD SOT23
D3
BAW56
SMD SOT23
Notes
SMD Tant B
SMD 1812
SMD 1812
SMD 1812
SMD 1812
SMD 1812
SMD 1812
std. Dia
12.5mm
SMD 1206
SMD Tant B
std. Dia
6.3mm
SMD 1206
std. Dia
6.3mm
A4-Common
Cathode
A1-Common
Anode
A1-Common
Anode
A4-Common
Cathode
D4
BAV70
SMD SOT23
L1
20µH
(ZXFN1000)
std.
Custom
core
L2
20µH
(ZXFN1000)
std.
Custom
core
ISSUE 1 -MARCH 2001
15
ZXCD1000
PACKAGE DIMENSIONS
EXPOSED PAD
C
S
h x 45
3
2
S
Y
M
B
O
L
1
H
E
SEE DETAIL "A"
BOTTOM VIEW
END VIEW
TOP VIEW
e
.010
b
A2
DIMENSIONS IN INCHES
MIN.
NOM. MAX.
A .058
.061
.066
A1 .001
.003
.005
A2 .055
.058
.061
.012
b .008
.010
c .007
D .189
.194
.196
E .150
.154
.157
e
.025 BSC
H .228
.236
.244
h .010
.016
.013
.035
.025
L .016
.005
.007
SC .002
OC
0
5
8
A
SEATING
PLANE
L
C
OC
DETAIL "A"
D
A1
SEATING PLANE
SIDE VIEW
Zetex part ordering information (per channel)
Qty per Device
channel
Description
Package
T&R Suffix
eQSOP16 TA, TC
1
ZXCD1000EQ16
Class D modulator
2
ZXFN1000
Custom magnetics
2
ZXM63N03X
N Channel MOSFET
MSOP8
TA, TC
2
ZXM63P03X
P Channel MOSFET
MSOP8
TA, TC
TA, TC
Zetex plc.
Fields New Road, Chadderton, Oldham, OL9-8NP, United Kingdom.
Telephone: (44)161 622 4422 (Sales), (44)161 622 4444 (General Enquiries)
Fax: (44)161 622 4420
Zetex GmbH
Streitfeldstraße 19
D-81673 München
Germany
Telefon: (49) 89 45 49 49 0
Fax: (49) 89 45 49 49 49
Zetex Inc.
47 Mall Drive, Unit 4
Commack NY 11725
USA
Telephone: (631) 543-7100
Fax: (631) 864-7630
Zetex (Asia) Ltd.
3701-04 Metroplaza, Tower 1
Hing Fong Road,
Kwai Fong, Hong Kong
Telephone:(852) 26100 611
Fax: (852) 24250 494
These are supported by
agents and distributors in
major countries world-wide
© Zetex plc 2000
Internet:http://www.zetex.com
This publication is issued to provide outline information only which (unless agreed by the Company in writing) may not be used, applied or reproduced for
any purpose or form part of any order or contract or be regarded as a representation relating to the products or services concerned. The Company reserves
the right to alter without notice the specification, design, price or conditions of supply of any product or service.
ISSUE 1 - MARCH 2001
16