DAEV9118.001
29 January, 2002
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MAS9118 evaluation kit provides all the necessary
hardware (excluding PC running Windows 9X) and
software for evaluation of MAS9118 audio DAC with
class-D output stage.
MAS9118 evaluation board has two adjustable
voltage regulators for testing the input level shifters
of MAS9118 and for selecting various supply
voltages for class-D output driver.
The evaluation kit includes an on-board buzzer.
Optionally an external buzzer or loudspeaker can be
easily connected to the demo board by using a
jumper connector.
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•
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MAS9118 audio DAC with class-D output stage
Power regulation
Adjustable driver voltage
Parallel port interface for PC
Possibility to play wave files
Software synthesizer for generating a test signal and multi-tone melodies
F
OSC
(8 MHz)
To the parallel port of a PC
MAS9118 Eval V2.0
R2
VDDI
(1.8 V)
R1
VDD
(3.6 V)
+7.5 V (600 mA)
0 V (ground)
X5
X3
X4
JP1
Buzzer and speaker configurations:
A) Buzzer on circuit board
(Citizen CHB-03E)
JP1
Jumper between
pins 1 & 2
buzzer
MAS9118
MAS9118 Eval V2.0
Reset
Figure 1.
B) External buzzer or loudspeaker
X6
JP1
Between
pins 2 & 4
1 (4)
DAEV9118.001
29 January, 2002
48,&. 67$57
1
2
3
4
5
6
7
Copy files from the disk to the desired directory of a PC
Restart the PC in MS-DOS mode.
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Connect the data bus between the two evaluation boards (PC adapter and buzzer boards)
Connect buzzer or loudspeaker to the JP1 of the buzzer board, see figure 1
Connect 7.5 V power supply to the buzzer board. Adjust current limiter to 600 mA if possible
Connect adapter board (PCB with 25-pin D-type connector) to the parallel port of the PC
Run the evaluation kit program by typing: buzzer –p XX –m YY (XX is the number of the parallel port, YY
is the melody number)
Example: buzzer –p 1 –m 0
8
You should hear the signal from the buzzer or the loudspeaker
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The hardware is partitioned into two PCBs in order
to provide robust data transfer from a PC to
MAS9118 even if the distance between the two is
several meters. Most of the components on
evaluation board are used for the data transfer from
the PC to MAS9118.
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The time domain is synchronized to the crystal
oscillator frequency (F
RVF
) of 8.0 MHz. Other clock
frequencies are generated from this frequency as
follows:
F
osc
F
MCLK
= 8 = 1000 kHz
F
osc
F
XCS
= 128 = 62.5 kHz
F
osc
F
CCLK
= 8 = 1000 kHz
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The PCB including buzzer (buzzer board) adjusts
supply and signal voltages of MAS9118. It has five
jumpers, see figure 1.
X3 is used for connecting 5 V for the interface logic
(default position is ON).
X5 is used for connecting the interface voltage level
to MAS9118 (default position is ON). The voltage is
normally 1.8 V and can be adjusted by R2 trimmer.
X4 is used for connecting the operating voltage to
MAS9118 (default position is ON). The voltage is
normally 3.6 V and can be adjusted by R1 trimmer.
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X6 is used for generating reset signal to MAS9118
(default position is OFF). Since MAS9118 has
power-on-reset this jumper can normally be off.
JP1 is used for connecting a buzzer, a loudspeaker
or a measurement instrument to the output pins of
MAS9118 (OUTP, OUTN).
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The data is read from the PC at the rate of F
XCS
(62.5 kHz). MS-DOS mode is required in order to
quarantee continuous data flow.
Note that the buzzer.exe program will disable the PC
system clock interrupt and stop the PC system time.
Therefore, it is recommended to boot the PC after
using the program in order to retrieve the right
system time.
The help of the buzzer.exe program is shown each
time the program is started.
The melodies are started by typing
EX]]HU S SRUW ±P PHORG\
Zhere
#port is the parallel port of the PC used for
the data transfer (0…3) and
PHORG\
is the number of the pre-programmed
melody (0…5).
(1)
(2)
(3)
2 (4)
DAEV9118.001
29 January, 2002
The audio quality test is best performed by using the
build-in sine generator of the buzzer.exe program. It
is started by typing
EX]]HU ±S SRUW ±V IUHT ±D DWWHQ
where
SRUW
is the parallel port of the PC used for
the data transfer (0…3) and
#IUHT is the sine frequency in Hz and
#DWWHQ is the attenuation of the sine amplitude in dB
(≥ 0).
For example, a test signal using parallel port 1 of the
PC, having peak signal to noise ratio at 1000 Hz and
1 dB attenuation of the maximum level is obtained
by typing
EX]]HU ±S ±V ±D
The wave files can be played by typing
EX]]HU ±Z ILOHZDY
[-f/F] [-c/C] [-d/D]
where
ILOHZDY
is the name of an 8-bit wave file
(sample frequency 62.5 kHz) and
-f turns additional highpass filter on (default)
-F turns additional highpass filter off
-c turns dynamic compander on (default)
-C turns dynamic compander off
-d turns dynamic booster on
-D turns dynamic booster off (default)
Note that the wav file has to be in a specific format.
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Additionally the wav files have to be in mono and
signed 8-bit format. The conversion from the CD
quality data (44.1 kHz, 16-bit, stereo) to the
evaluation kit's format (62.5 kHz, 8-bit, mono) can
be easily made with the most of the audio softwares.
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At the nominal output voltage of 3.6 V the on-board
voltage regulator (R1) can deliver required current to
the class-D output stage of MAS9118. At higher
voltages (up to 5.5 V) an external voltage source
should be used if the load is as low as 8 Ohms. The
external voltage source should be connected
between the lower pin of the jumper X4 (jumper
short removed) and the left pin of the jumper X6
(board ground), see figure 2.
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Figure 2.
X5
X3
X4
JP1
External power supply
buzzer
X6
MAS9118 Eval V2.0
+
-
3.6-5.5 V
MAS9118 evaluation kit consists of the following
deliverables:
1
2
3
MAS9118 evaluation board V2.0 (2 pieces)
Control bus cable
Disk containing buzzer.exe, cwsdpmi.exe,
sample wave files and the data sheets of
MAS9118 and the evaluation kit
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Due to the class-D operation MAS9118 generates
some out-of-band noise, which may cause problems
for test equipment when using automatic scaling.
For example Audio Precision audio analyzer will
generate much additional distortion due to signal
overload when auto scaling is used. Auto scaling
does not take into account the existing high
frequency components causing wrong scaling and
leading to distortious signal clipping.
Also some test equipment can not synchronize to
the test sine frequency due to the out-of-band noise.
Usually a first order RC filter, when added before the
input of the test equipment, filters out the high
switching frequency. Remember to use high quality
components (especially capacitor) in order to
minimize the additional distortion caused by this
filter.
The evaluation board consumes about 0.5 A current
when the load is 8 Ohms. Use low ohmic wires from
power supply to the evaluation board.
3 (4)
DAEV9118.001
29 January, 2002
/2&$/ ',675,%8725
0,&52 $1$/2* 6<67(06 2< &217$&76
MICRO ANALOG SYSTEMS OY
Kamreerintie 2, P.O.Box 51
FIN-02771 Espoo, FINLAND
Http://www.mas-oy.com
Tel. (09) 80521
Tel. Int. +358 9 80521
Telefax +358 9 8053213
Email: info@mas-oy.com
127,&(
Micro Analog Systems Oy reserves the right to make changes to the products contained in this data sheet in order to improve the design or
performance and to supply the best possible products. Micro Analog Systems Oy assumes no responsibility for the use of any circuits shown
in this data sheet, conveys no license under any patent or other rights unless otherwise specified in this data sheet, and makes no claim that
the circuits are free from patent infringement. Applications for any devices shown in this data sheet are for illustration only and Micro Analog
Systems Oy makes no claim or warranty that such applications will be suitable for the use specified without further testing or modification.
4 (4)
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