Overcurrent protection circuit capable of flexibly adapting to various power tubes in DCDC converter

The invention relates to the technical field of DCDC converters, in particular to an overcurrent protection circuit capable of being flexibly adapted to various power tubes in a DCDC converter. Comprising a current control circuit and a comparison and judgment circuit, a bias current Ibias output by the current control circuit is connected with a negative input end of the comparison and judgment circuit, and a positive input end of the comparison and judgment circuit is connected with a feedback signal LX on a lower bridge switch; wherein the current control circuit comprises a first cascode current mirror which is composed of M5-M8 tubes and is used for generating a quiescent current I2; the feedback branch is composed of a phase inverter and M9-M10 tubes, and is used for generating dynamic current I3; the basic current mirror is composed of M1-M4 tubes; the second cascode current mirror is composed of tubes from M11 to M18; according to the invention, the bias current Ibias is trimmed through the overcurren