KTC noise on direct injection from IR diodes

When a MOSFET is used to transfer the photogenerated charge from an IR diode to the input of a CCD in the "direct-injection" mode, Johnson-Nyquist noise on the MOSFET transconductance results in a variance in the charge integrated in the CCD which is approximately equal to KTC under the assumption of large diode resistance, where C is the detector capacitance.