In this paper, a LDO circuit for bio-implantable applications is proposed. Even if the load current increases, the open-loop gain of the amplifier can be maintained by using an additional unit gain buffer, a level-shifter, and a pass transistor. This ...
In this paper, a LDO circuit for bio-implantable applications is proposed. Even if the load current increases, the open-loop gain of the amplifier can be maintained by using an additional unit gain buffer, a level-shifter, and a pass transistor. This is done by sensing the amount of output voltage variations and passes it onto a buffer and a level shifter so that the change is suppressed. Consequently, the amplifier accuracy and load regulation have been improved. Simulation results are obtained by HSPICE in a 0.18㎛ CMOS standard technology. When the current at the load increased from OA to 200μA, the open loop gain of the previous regulator dropped from 79㏈ to 21㏈, whereas that of the proposed regulator dropped from 76㏈ to 51㏈.