Hello,
could you please suggest design ideas or even existing circuit parts to fulfill the following circuit function:
Half-wave recification and + peak detection of a DC to 1kHz squarewave signal.
The following working conditions:
INPUT SIGNAL
- input source resistance is 1kOhms
- input signal voltage ranges from -12V to +7V.
- input signal can be a dc voltage
- Input signal can be a square wave, too (neg./pos. voltage as above).
- the square wave has f=1kHz and variable duty cycles from 3% to 100% (DC)
CIRCUIT
- the circuit should not distort the input signal (-> high input resistance)
- only the positive voltage portion is needed (half-wave rectification)
- peak detection of the positive voltages is required
- The peak detection circuit has to work from DC down to 3% duty cycle signal (so the peak detector has to charge within 30us).
- A (constant) output voltage bias against the input positive voltage is acceptable
The simple circuit consisting of a diode + NPN emitter follower works well on principle, but the temperature drift is too high (Tamb=-20...+70°C).