, just keep me posted when you decide to do a kit run
Hi sled. I don't have any problems soldering surface mount stuff with a standard iron. Just takes practice.
If you're interested in hearing the MP7720 send me an email and we might be able to work something out. As of right now I don't have enough time to finish a number of projects I've got going, including this one.
If you're interested in hearing the MP7720 send me an email and we might be able to work something out. As of right now I don't have enough time to finish a number of projects I've got going, including this one.
Forgive me for resurrecting this old thread. I am working on a audio project and I am using the MP7731. Page 5 of the data sheet containes this statement:
I have stared at Figure 1 until my eyes water, but I cannot see a resistive voltage divider other than the gain setting resistors R1, R4 and R6,R8. Can one of you guys explain where the divider that sets the input voltage at Vdd/2 is in this circuit?
I have stared at Figure 1 until my eyes water, but I cannot see a resistive voltage divider other than the gain setting resistors R1, R4 and R6,R8. Can one of you guys explain where the divider that sets the input voltage at Vdd/2 is in this circuit?
There is none. My impression is that none is needed. The feedback resistors R1 and R8 should take care of the bias.
FauxFrench is correct. The positive differential input pins do not need to be DC biased at half supply voltage with a voltage divider when using the bridged configuration.
If you use it in a two channel single ended configuration you will need to bias those pins at half supply voltage. If you use a dual supply voltage (+/-9V) the bias voltage would be at 0V and you can eliminate the coupling capacitor. They used to have app notes about doing that with the other single ended chips.
I do have a single ended audio signal, but I am converting it to a differential signal with a differential amp before I send it to the 7731. I am thinking that a pair of 9V batteries to provide the + and - supply would work in this device where I need occasional audio loud enough to hear from a 4 ohm speaker. The other requirements are to be small and lightweight.
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