A high speed current output stage with Digital assistant circuit

This paper introduces a novel current output stage with a Digital assistant circuit, which can obtain high speed performance. The output current stage in this paper is used in a switching driving circuit. The principle of this proposed circuit is different with the conventional structure. The added Digital assistant circuit includes a charge and discharge block, a keep block. Depended on simple digital control logic, the rise time and the fall time of the switching output current are shorten remarkably. The complete circuit was designed with the model parameters of a 0.35 um mixed-signal CMOS process and simulated with HSPICE. The simulation results show the rise time of the proposed output current stage is 20 ns and the regulating time for output current to be steady is only 100 ns under the maximum 90 mA output current condition.