MAS9116 / WM8816 Stereo Digital Volume Control
Using an MAS9116 / WM8816 with a 2-bit Gray code rotary-encoder making it a hi-end digital volume controller from -112 dB to +15.5 dB.
Pin numbers:
Pin 1 AVCC - Power Supply (analog)
Pin 2 LMO - External Amp. Neg. Input (left)
Pin 3 LFO - Feedback Signal from Ext. Amp. (left)
Pin 4 LIN - Input Left Channel
Pin 5 LGND - Signal Ground (left channel)
Pin 6 XCS - Chip Select Input of Serial Input
Pin 7 DVCC - Power Supply (digital)
Pin 8 XMUTE - Mute Input
Pin 9 DATA - Data I/O of Serial Interface (tristate)
Pin 10 CCLK - Clock Input of Serial Interface
Pin 11 DGND - Ground (digital)
Pin 12 RGND - Signal Ground (right channel)
Pin 13 RIN - Input Right Channel
Pin 14 RFO - Feedback Signal from Ext. Amp. (right)
Pin 15 RMO - External Amp. Neg. Input (right)
Pin 16 AGND - Ground (analog) |
256 step digital potmeter chips:
BH3532FS (Rohm)
AD5162 (Analog Devices)
DS1267 (Dallas/Maxim)
X9260 (Intersil)
PGA2311 (Texas Intruments) |
Info about the MAS9116 / WM8816:
The MAS9116 (identical to the WM8816) is a stereo volume IC for high-end audiosystems and/or audiomixers. The volume ranges from -111.5 dB to +15.5 dB, so it is not an attenuator like a digital potmeter (which means; only lowering the volume down from 0 dB) It also has a signal peak level detector (DAC with 8 bit resolution + comparator), with this you can i.e. create a VU-meter, or easely measure audio levels. The stepsize is 0.5 dB and it has two independent audiochannels (stereo or balanced output) you can put as many MAS9116's as you want in your circuit. The volume level data is set by two bytes (16bits) of serial data, and has a 4-wire interface (Data, Clock, Chip Select and Mute) It has a very good dynamic range of 130 dB!, and even higher. Muting level is -113 dB. More info can be found in the datasheet. If you look to the IC you notice that the analog pins (that are pins 1, 2, 3, 4, 5, 12, 13, 14, 15 and 16) are at one side and the digital (pins 6, 7, 8, 9, 10, 11) placed at the other side, this is done to seperate the analog and digital, so that the PCB design will be easier and the circuit working better. Next a diagram which controls the MAS9116's two channels simultainiously (stereo or balance control):
1x MAS9116 (or WM8816)
1x AT90S2313
1x NE5532 (dual OpAmp)
1x ddm 427 rot-enc.
1x 4 MHz resonator
1x 78L05
4x 10uF/16V
2x 220n multilayer
1x 22p ceramic
4x 22k |
3x 100n multilayer
1x 47uF/16V
1x 10k
1x 100 ohm
1x 10uF/35V tantalium
1x TSOP II adapter
1x IC socket DIP20
1x IC socket DIP8
3x 2 x 4 strips
1x Knob for ddm 427 |
How can this be fixed ?
I took a TSOP II multi-adapter from Conrad, and soldered the MAS9116 on one upper side (no SO16 adapter available), like this:
Next take two 2x4 strips and solder them on the multi-adapter next to where the MAS9116 sits, like this:
Next take a hobby board and place all the components in an orderly way on it, and lay and solder the wiring on the bottom, here one example:
Or buy an evaluationboard (can be ordered at: Profusion), like the one from Wolfson with the WM8816 (not cheap, but professional PCB with SMD components, works very good) In the near future I will create my own evaluationboard, which will be a low-cost version, and will have extended features. Here a picture of the WM8816 evaluation board:
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