发明名称 |
Duty cycle adjusting circuit and adjusting method |
摘要 |
The present invention relates to a square wave generator circuit, an integrated circuit, a DC/DC converter and an AC/DC converter. The square wave generator circuit comprises a first mirror current branch which is connected with ground via a first switching element and a first capacitor in parallel with the first switching element, wherein the first switching element is operable to be opened or closed periodically under control of a first clock signal so as to generate a first sawtooth wave signal at a non-grounded terminal of the first capacitor; a second mirror current branch which is connected with ground via a second switching element and a second capacitor in parallel with the second switching element, wherein the second switching element is operable to be opened or closed periodically under control of a second clock signal synchronous with the first clock signal so as to generate a second sawtooth wave signal at a non-grounded terminal of the second capacitor; and a comparator, one input terminal of which is connected to the non-grounded terminal of the first capacitor and the other input terminal of which is connected to the non-grounded terminal of the second capacitor, so that a square wave signal can be outputted at an output terminal of the comparator, wherein a duty cycle of the square wave signal depends on a ratio of a capacitance of the second capacitor to a capacitance of the first capacitor. |
申请公布号 |
US8970270(B2) |
申请公布日期 |
2015.03.03 |
申请号 |
US201314097114 |
申请日期 |
2013.12.04 |
申请人 |
iWatt Integrated Circuits Technology (Tianjin) Limited |
发明人 |
Zhao Xiaogang |
分类号 |
H03K3/017 |
主分类号 |
H03K3/017 |
代理机构 |
Fenwick & West LLP |
代理人 |
Fenwick & West LLP |
主权项 |
1. A square wave generator circuit, comprising:
a first mirror current branch which is connected with ground via a first switching element and a first capacitor in parallel with the first switching element, wherein the first switching element is operable to be opened or closed periodically under control of a first clock signal so as to generate, in a first direction, a first sawtooth wave signal at a non-grounded terminal of the first capacitor; a second mirror current branch which is connected with ground via a second switching element and a second capacitor in parallel with the second switching element, wherein the second switching element is operable to be opened and closed periodically under control of a second clock signal synchronous with the first clock signal so as to generate, in a same direction as the first direction, a second sawtooth wave signal at a non-grounded terminal of the second capacitor; and a comparator, one input terminal of which is connected to the non-grounded terminal of the first capacitor and the other input terminal of which is connected to the non-grounded terminal of the second capacitor, so that a square wave signal can be outputted at an output terminal of the comparator, wherein a duty cycle of the square wave signal depends on a ratio of a capacitance of the second capacitor to a capacitance of the first capacitor. |
地址 |
Tianjin CN |