Design And Research Of High Power Supply Rejection Ratio Low-dropout Linear Voltage Regulator

With the prevalence of handsets, the requirement for power management is becoming more complex and more rigid. At present, many aboard companies still occupy the most market of power management ICs. And it has much great importance to require such a big market. Therefore, it is of great importance to study the low-dropout (LDO) linear voltage regulator circuit.The object of this thesis is to design a high power supply rejection ratio (PSRR) low-dropout (LDO) linear voltage regulator. It adopts TSMC 0.6μm CMOS process, which has the high power supply rejection ratio (more than 90dB at low frequency, around 40dB at high frequency), wide input voltage range (3.0V-5.5V). The output voltage is 2.8V. When the load current is 150mA, the dropout voltage is only 160mv. The circuit is primarily used to power supply of the circuit, which is sensitive to power ripple, such as RF, VCO and so on. In addition, the thermal shutdown and current limit sub-blocks are also integrated in this chip, which guarantee the electric circuit working in safe operation area. The IC has high PSRR and low output noise based on the above technical advantages. At the same time, it has the most simple outer circle circuit, greatly reducing the cost. It is used as power supply for those systems: handset, MP3 player, PDA, numeral camera and so on.During circuit designing, the basic theory of LDO linear voltage regulator, including basic working principle and the main circuit parameters, is given first. Then the technique is studied and the whole circuit of the IC is designed based on the performance requirement. Finally, the keys and difficulties of LDO linear voltage regulator are studied and solved. Applying Cadence and Spectra, the whole chip and its sub-block circuits are simulated, and more, the reasonable electric circuit datas are given. The simulation results indicate that the IC has achieved their function object.At the end of this thesis, a conclusion is drawn and the prospect of future work is given combined with finished research.