npatel

hi all, i am building a photodiode amplifier with an opamp in inverting mode. The opamp is powered with +/-5V. it has 95 megs of feedback resistor and a capacitor in parallel to prevent oscillations. Can anyone tell me what value of the capacitor should i use to get stable readings. Some literature suggests it to make it the same as the input capacitance of the photodiode. Also the output of the opamp is fed in to an A/D. Can anyone suggest a suitable sampling frequency for the A/D. Thanks

Can anyone suggest a voltage regulator IC that will take in 9VDC @ 1A and produce +5V and -5V @ 500mA as outputs. Thanks

Thanks for your reply Audioguru, here are the specs input current ~1A input voltage - 2V output voltage- 7V i do not need any current amplification. I am trying to amplify the voltage output of a Li-ion battery and feed it into a 5V regulator so that when the external power is disconnected the system is still running. Typically all 5V regulators that i have seen need Vin of 7-9V to maintain line regulation, thus the need for voltage amplification. Also i cannot use any opamps. compressors are not required. The amplifier should have high i/p impedance and low o/p impedance to prevent loading. Thanks for your help.

hi all, need to build a voltage amplifier to amplify 1.2 to 4 V to 6-9V. cannot use any opamps. any help is appreciated Thanks