Current generation circuit and achievement method thereof

The invention discloses a current generation circuit and an achievement method thereof. The circuit includes a positive temperature coefficient PTAT current generation circuit for generating a currentI0 with a positive temperature coefficient, a biasing circuit for stabilizing the gate voltage of each PMOS tube of mirror image constant current sources at a design value, the first mirror image constant current source for providing the current I0 for the positive temperature coefficient PTAT current generation circuit and making the current flow to the second mirror image constant current source, the second mirror image constant current source for converting the current I0 with the positive temperature coefficient and in form of the current source into a current Iref with the positive temperature coefficient and in form of current sink, and a negative temperature coefficient CTAT current generation and combination circuit for generating a current with a negative temperature coefficientand combining the current