- #1

DailyDose

- 25

- 0

Hey all,

This newb needs help understanding the posted circuit. Real quick, I'm going to post what I understand from left to right.

R53 and R62 = Voltage Divider

D2 = Clamping Diode (Clamping to 3.3V)

R45 = R1 in basic (R2/R1)Vin = Vout op amp formula

This is where I get stuck.

Let's call the node b4 R45 Vin. We would have [(Vin-Vref)/R45] = [(Vref - Vo)/R2] - however no R2. Instead, there's a diode that is in the off (depending on how you look at it) preventing any output from the first op-amp. Where then I guess the second OP Amp equation looks like Vo = [(Vin-Vref)/R45]. I am pretty sure I am missing some inverse logic in all of this, but regardless, I hope I got what I was trying to say across. Click Here for the Op-Amp datasheet. Any help would be greatly appreciated. Namely, what is that diode doing? What's the purpose of this circuit? Thank you.

This newb needs help understanding the posted circuit. Real quick, I'm going to post what I understand from left to right.

R53 and R62 = Voltage Divider

D2 = Clamping Diode (Clamping to 3.3V)

R45 = R1 in basic (R2/R1)Vin = Vout op amp formula

This is where I get stuck.

Let's call the node b4 R45 Vin. We would have [(Vin-Vref)/R45] = [(Vref - Vo)/R2] - however no R2. Instead, there's a diode that is in the off (depending on how you look at it) preventing any output from the first op-amp. Where then I guess the second OP Amp equation looks like Vo = [(Vin-Vref)/R45]. I am pretty sure I am missing some inverse logic in all of this, but regardless, I hope I got what I was trying to say across. Click Here for the Op-Amp datasheet. Any help would be greatly appreciated. Namely, what is that diode doing? What's the purpose of this circuit? Thank you.