Gain linearity correction circuit for MOS circuits

摘要

Gain linearity problems caused by impact ionization in a active MOS device are avoided by connecting an MOS shield device in series with the active MOS device so that the overall supply voltage is split across two devices, keeping both devices in a region of operation well below where impact ionization becomes a significant problem. The gate of the MOS shield device is maintained at a voltage proportional to its drain voltage, thereby keeping the device in the saturation mode and avoiding an abrupt mode change associated with prior art shield circuits.