  This paper presents an analytical model to quantify noise in a bolometer
readout circuit. A frequency domain analysis of the noise model is presented
which includes the effect of noise from the bias resistor, sensor resistor,
voltage and current noise of amplifier and cable capacitance. The analytical
model is initially verified by using several standard SMD resistors as a sensor
in the range of 0.1 - 100 Mohm and measuring the RMS noise of the bolometer
readout circuit. Noise measurement on several indigenously developed neutron
transmutation doped Ge temperature sensor has been carried out over a
temperature range of 20 - 70 mK and the measured data is compared with the
noise calculated using analytical model. The effect of different sensor
resistances on the noise of bolometer readout circuit, in line with the
analytical model and measured data, is presented in this paper.
