I'm new learning to read circuits. so please bear with me as i ask some basics. Here is the circuit from a document i am reading about Microphones and pre-amps.
The actual circuit is from a document listed below.
http://www.ti.com/lit/ug/tidu765/tidu765.pdf
I'm not sure how the circuitry in the pre-amp actually works. I'll write my questions one by one so i can better understand.
1. why is the direction of the Current (Imic, Idc, Iac ) pointing towards the Electret Microphone? I thought the current should flow out into the next stage , towards the preamp ?
2. What is the significance of a resistor/capacitor combination across the circuit? Why not only have resistors to control the flow of current ?
3. The document states "the gain of the pre-amp is determined by R2 but the noise gain of the op amp is determined by the ratio of R2 to R1" . i don't understand how the Resistance R2 can control the gain of the pre-amp.
4. What is the significance of the module at the '+ve' end of the Op-amp U1.
5. What book would one recommend to get started with circuit designing. ?
Thank you.
The actual circuit is from a document listed below.
http://www.ti.com/lit/ug/tidu765/tidu765.pdf
I'm not sure how the circuitry in the pre-amp actually works. I'll write my questions one by one so i can better understand.
1. why is the direction of the Current (Imic, Idc, Iac ) pointing towards the Electret Microphone? I thought the current should flow out into the next stage , towards the preamp ?
2. What is the significance of a resistor/capacitor combination across the circuit? Why not only have resistors to control the flow of current ?
3. The document states "the gain of the pre-amp is determined by R2 but the noise gain of the op amp is determined by the ratio of R2 to R1" . i don't understand how the Resistance R2 can control the gain of the pre-amp.
4. What is the significance of the module at the '+ve' end of the Op-amp U1.
5. What book would one recommend to get started with circuit designing. ?
Thank you.