An LDO without a Capacitor Required in Applications

Abstract

Linear voltage regulator with low voltage dropout is widely used in DC/DC circuits because of the advantages of simple structure, low noise, high efficiency, and small package size. In this paper, high stability LDO linear voltage regulator with low static current is designed. By using a voltage detection module, the pass transistor in the regulator can be quickly regulated or switched on and off under load transient conditions. In addition, the stability of the LDO is improved by using an NMOS pass transistor and diode clamp architecture. The test results show that the typical values of linear adjustment and load adjustment of the voltage regulator are 20 mV and 200 mV, respectively. The maximum output current is 60 mA, the load current is 20 mA, and the output pressure difference under 4.8 V output voltage is 210 mV. Compared with traditional LDO, although the output current is not the maximum, the difference and stability of output pressure are greatly improved.