Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

series connection of power audio amplifier

AssemblyLine

Member level 1
Joined
Nov 1, 2013
Messages
35
Helped
0
Reputation
0
Reaction score
1
Trophy points
1,288
Activity points
1,607
Hello
I intend to use this IC CM102S, which is a USB audio with built-in amplifier 2W

1651903256526.png



I need more power so I want to use another amplifier , somethink like 10 W - PAM8106

1651903962195.png



My question is : could I connect in series these two amplifiers : the output of CM102 to be connected to the inputs of PAM8106
 

KlausST

Super Moderator
Staff member
Joined
Apr 17, 2014
Messages
21,990
Helped
4,591
Reputation
9,196
Reaction score
4,812
Trophy points
1,393
Activity points
145,178
Hi,

The CM102 darasheet isn't very detailed. I miss a lot of informations.
* like output type (class)
* output offset voltage
* speaker connection
* application note
...

So it's a lot of guessing.
* I'm rather sure it's a classAB or classB output. Thus you should be able to connect an external amplifier.
* it will have DC offset you have to get rid of with a series capacitor
* I recommend to connect the "-In" of the power amplifier to CM102_VRef to avoid loud "plop" on powerON.

Klaus

Added: Don't try to build the power amplifier on a breadboard. You need a proper PCB layout. Read datasheet and application notes.
 

Audioguru

Advanced Member level 5
Joined
Jan 19, 2008
Messages
9,397
Helped
2,149
Reputation
4,292
Reaction score
1,993
Trophy points
1,393
Location
Toronto area of Canada
Activity points
59,186
The output level of the CM102S is only 0.18W into 8 ohms per channel, headphones level.
The output of the PAM8106 amplifier is 6W into 8 ohms per channel with low distortion and a 12V supply.
The PAM8106 has 32 pads that are almost impossible to solder.
 

barry

Advanced Member level 5
Joined
Mar 31, 2005
Messages
5,681
Helped
1,152
Reputation
2,316
Reaction score
1,220
Trophy points
1,393
Location
California, USA
Activity points
30,955
The output level of the CM102S is only 0.18W into 8 ohms per channel, headphones level.
The output of the PAM8106 amplifier is 6W into 8 ohms per channel with low distortion and a 12V supply.
The PAM8106 has 32 pads that are almost impossible to solder.
.18w=> 1.2V. Probably enough to drive the PAM8106 (I didn’t look that closely). Might be able to use different load resistor for CM102.

PAM8106 is not ”impossible to solder”. You just the proper tools.
 

AssemblyLine

Member level 1
Joined
Nov 1, 2013
Messages
35
Helped
0
Reputation
0
Reaction score
1
Trophy points
1,288
Activity points
1,607
The output level of the CM102S is only 0.18W into 8 ohms per channel, headphones level.
The output of the PAM8106 amplifier is 6W into 8 ohms per channel with low distortion and a 12V supply.
The PAM8106 has 32 pads that are almost impossible to solder.

Soldering it is not an issue for me, but thank you
--- Updated ---

.18w=> 1.2V. Probably enough to drive the PAM8106 (I didn’t look that closely). Might be able to use different load resistor for CM102.

PAM8106 is not ”impossible to solder”. You just the proper tools.
I have found a similar IC, from all mighty TI PCM2704C which also can drive headphones but also can be connected to external power amplifier, they warn about mathcing input impedance of amplifier

1653054857549.png


But PCM output is directly the DAC itself
CM102s output is amplifier

Is my feeling right that it could work?

What could happen if impedances are not matched? How to match them ? If I choose any (not really any) amplifier, can I match the ICs with RLC parts?
I know I have serious knowledge gaps in electronics, so please bear with me :)
 
Last edited:

LaTeX Commands Quick-Menu:

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top