| 摘要 |
A crystal oscillator, including: a voltage stabilizing unit, a transconductance unit, a feedback resistor, a crystal resonator and at least two ground capacitors. The voltage stabilizing unit includes a current source and a first branch circuit including PMOS and NMOS connected in series, PMOS has its source connected to output of the current source, PMOS and NMOS have their gates connected to drains thereof, and NMOS has its source connected to ground. The transconductance unit includes a second branch circuit including PMOS and NMOS connected in series, PMOS has its source connected to output of the voltage stabilizing unit, PMOS and NMOS have their gates connected to input of the crystal resonator and one end of the resistor, and have their drains connected to output of the crystal resonator and another end of the resistor. The capacitors are connected to two ends of the crystal resonator respectively and ground. |
| 主权项 |
1. A crystal oscillator, comprising: a voltage stabilizing unit, a transconductance unit, a feedback resistor, a crystal resonator and at least two ground capacitors, wherein
the voltage stabilizing unit comprises: a current source and a first branch circuit, wherein the first branch circuit comprises a P-type Metal-Oxide Semiconductor (PMOS) and an N-type Metal-Oxide Semiconductor (NMOS) successively connected in series, the PMOS of the first branch circuit has its source connected to an output of the current source; in the first branch circuit, the PMOS has its gate connected to a gate of the NMOS, the PMOS has its drain connected to a drain of the NMOS, the PMOS has its gate connected to the drain of the NMOS, and the NMOS has its source connected to ground; the transconductance unit comprises a second branch circuit, wherein the second branch circuit comprises a PMOS and an NMOS successively connected in series; in the second branch circuit, the PMOS has its drain connected to a drain of the NMOS, the PMOS has its gate connected to a gate of the NMOS, the PMOS in the second branch circuit has its source connected to a voltage output of the voltage stabilizing unit; the PMOS and the NMOS in the second branch circuit have their gates both connected to an input of the crystal resonator, and the PMOS and the NMOS in the second branch circuit have their drains both connected to an output of the crystal resonator; the PMOS and the NMOS in the second branch circuit have their gates both connected to one end of the feedback resistor, and the PMOS and the NMOS in the second branch circuit have their drains both connected to another end of the feedback resistor; and the at least two ground capacitors are connected to two ends of the crystal resonator respectively and are connected to ground; wherein there are M first branch circuits, M is an integer larger than or equal to 1, the respective first branch circuits are connected in parallel; and the voltage stabilizing unit further comprises switches, each of which is used to control each of the first branch circuits. |
