Nanoampere-level current source with process voltage temperature compensation capability and design method

The invention discloses a nanoampere-level current source with process voltage temperature compensation capability and a design method. The nanoampere-level current source comprises a current bias circuit and a self-adaptive constant-current bias voltage generation circuit, the current biasing circuit is used for realizing nanoampere-level sub-threshold current biasing; the bias voltage generating circuit is used for extracting the characteristics of a target circuit under the conditions of different processes, supply voltages and temperatures so as to obtain a corresponding bias voltage change characteristic curve and guide the construction of the current bias circuit. By adopting the nanoampere-level current source with the process voltage temperature compensation capability, accurate current bias can be provided for a sub-threshold circuit, meanwhile, the nanoampere-level current source has the capability of resisting process, power supply voltage and temperature fluctuation, the use of a large-size curren