关键词: 振荡器, 电源芯片, 电流源

Abstract: A multi-mode high-precision oscillator is designed, which is applied to the switching power supply chip to provide a stable clock source for the internal logic of the chip, has three working modes, and improves the flexibility of the whole circuit. Low dropout regulator(LDO) and zero temperature drift current source are designed in the circuit, so that the output frequency of the oscillator is not easily affected by the change of voltage and temperature. At the same time, the technology of repairable adjustment is adopted to adjust the charging current of the capacitor in two directions to eliminate the error caused by process. The circuit is designed based on CSMC 0.25 μm 2P5M process and simulated by HSPICE. The results show that the output frequency changes by 1.1 kHz in the input voltage range of 3.0-6.0 V and the charge rate is 0.22%; Within the temperature range of -55-125 ℃, the output frequency changes by 2.1 kHz and charge rate is 0.41%.

Key words: oscillator, powersupplychip, currentsource