Low dropout regulator circuit of transient response enhancing on-chip capacitor

The invention discloses a low dropout regulator (LDO) circuit of a transient response enhancing on-chip capacitor. The LDO circuit of the transient response enhancing on-chip capacitor comprises a voltage reference (VREF) generating circuit, an error amplifier (AMP), a power tube, a resistance string differential voltage cell, a charging channel, a discharging channel, and coupling capacitors Cc1 and Cc2. During the mutation of the load current, the designed charging channel or discharging channel is used for quickly charging or discharging the gate capacitance (Cg) of the power tube. The LDO circuit designs the novel and effective fast transient response compensation channel, achieves the frequency compensation while achieving the transient response compensation, and is capable of keeping the on-chip LDO stable within the change range of whole load current. The power tube of the LDO circuit can work in the linear region, the input and output voltages of the power tube can be controlled under 0.1 V. The external output capacitor does not need to be connected, the application circuit is simple, and the cost is low.