Отправлено AK 23 апреля 2002 г. 03:02 В ответ на: Ссылка: отправлено Vallav 22 апреля 2002 г. 14:36

From SECTION 5
HIGH IMPEDANCE SENSORS

At maximum sensitivity, the amplifier must be able to detect a diode current of 30pA. This implies that the feedback resistor must
be very large, and the amplifier bias current very small. For example, 1000M will yield a corresponding voltage of 30mV for this amount of current. Larger resistor values are impractical, so we will use 1000M for the most sensitive range. This will give an output voltage range of 10mV for 10pA of diode current and 10V for 10nA of
diode current. This yields a range of 60dB. For higher values of light intensity, the gain of the circuit must be reduced by using a smaller feedback resistor. For this range of maximum sensitivity, we should be able to easily distinguish between the light intensity on a clear moonless night (0.001fc) and that of a full moon (0.1fc)!

:-)))

• http://www.analog.com/technology/amplifiersLinear/training/pdf/Sensor_sect5.pdf

• Ответ: — Vallav   (23.04.2002 08:59, 434 байт)
  • У ADI свои цели — AK   (23.04.2002 15:29, 1012 байт)
    • Вариант: — Vallav   (23.04.2002 17:36, 500 байт)
      • Да нафиг там ОУ — AK   (23.04.2002 17:58, 112 байт)