The ADPD2210 from Analog Devices is a low-noise current amplifier designed to allow the use of smaller photodiodes by amplifying sensor signal currents by a factor of 24 while adding minimal noise. This amplification provides the system sensitivity of a large photodiode with the benefits of a smaller photodiode. A minimum linearity of 60 dB allows accurate extraction of very small, time-variant signals on top of large DC or low-frequency offsets. The ADPD2211 / ADPD2212 / ADPD2214 are optical sensors optimized for biomedical applications. Very low power consumption and near theoretical signal-to-noise ratio (SNR) are achieved by packaging an ultra-low-capacitance, deep-junction silicon photodiode operated in zero-bias photoconductive mode with a low-noise current amplifier.