| 主权项 |
1. An oscillation circuit comprising:
a ramp voltage generating unit configured to generate a ramp voltage; and a clock signal generating unit configured to generate a clock signal, wherein the clock signal generating unit includes:
a bias unit configured to apply one of the ramp voltage and a fixed voltage, as a bias voltage, to a resistor; andan oscillator configured to determine an oscillation frequency of the clock signal in response to a bias current flowing through the resistor, wherein the ramp voltage generating unit includes:
a first current source configured to generate a charging current of a capacitor;a second current source configured to generate a discharging current of the capacitor;a hysteresis comparator configured to generate a comparison signal by comparing a voltage across the capacitor with a threshold voltage; anda charging/discharging control unit configured to switch between charging and discharging of the capacitor in response to the comparison signal, wherein the voltage across the capacitor is output as the ramp voltage, wherein the bias unit applies a lower one of the ramp voltage and the fixed voltage, as the bias voltage, to the resistor, and wherein the ramp voltage generating unit includes a pull-up unit configured to make the ramp voltage higher than the fixed voltage at the start of the oscillation circuit. |
