CURRENT MIRROR WITH DEPLETION MODE MOS AND EMBEDDED NOISE FILTER

摘要

A current mirror with depletion mode MOS devices, and an embedded noise filter, operable with low supply voltage to provide a low-noise mirror current. The current mirror includes depletion-mode MOS transistors M1 and M2 configured as a current mirror, including a reference_current leg including M1 that receives an input reference current, and a mirror_current leg including M2, controlled by M1 to mirror the reference current as an output mirror current. An embedded noise filter (such as a low-pass RC filter) is coupled to M1 and M2, and configured to suppress noise in the input reference current from mirroring to the output mirror current. The embedded noise filter can be a low-pass RC coupled between the M1/M2 (low leakage) gates. Use of depletion-mode MOS devices with near-zero VT offers sufficient head-room for cascoding at low supply voltage to improve accuracy.

主权项

1. A current mirror circuit, comprising
depletion-mode MOS transistors M1 and M2 configured as a current mirror, including
a reference_current leg including M1 that receives an input reference current, anda mirror_current leg including M2, controlled by M1 to mirror the reference current as an output mirror current; and an embedded filter circuit coupled to M1 and M2, and configured to suppress noise in the input reference current from mirroring to the output mirror current.