Overload protection for amplifier of photodiode signal

A sensing device, comprising:

• a sensor, having first and second terminals;
• a trans-impedance amplifier (TIA), which has an input connected to the first terminal of the sensor, and which is configured to generate a current in response to an input signal that is incident on the sensor, the signal comprising pulses of a characteristic duration;
• a power supply, which is set to drive the sensor at a selected voltage;
• a resistor connected in series between the second terminal of the sensor and the power supply;
• and
• a capacitor connected to the second terminal in parallel with the sensor and the TIA and in series with the resistor,
• wherein respective values of the resistor and the capacitor are chosen, responsively to the characteristic duration of the pulses and the selected voltage, so that the capacitor provides sufficient energy to enable the TIA to generate a pulsed output signal in response to the pulses of the input signal, while preventing the current input to the TIA from exceeding a predefined upper limit on the current that is to be input to the TIA from the sensor.