China Electronic Technology Corporation, 24th Research Institute

Rong-Ke Ye

Lei Zhang

Guang-Bing Chen

Gang-Yi Hu

Can Zhu

Yong-Lu Wang

Zheng-Ping Zhang

Yu-Han Gao

Rong-Bin Hu

Yan Wang

Liang Li

Dong-Bing Fu

Xi Chen

Yu-Xin Wang

Xing-Fa Huang

Xue-Liang Xu

Xiao-Feng Shen

Ming-Yuan Xu

You-Hua Wang

Xu Huang

He-Quan Jiang

Jiao-Xue Li

Gnag-Yi Hu

A comparator offset voltage self-correction circuit is disclosed. A comparator offset voltage which is caused by the semiconductor process parameter randomness also has randomness. Due to the randomness of the comparator offset voltage, a reference voltage of a parallel comparator in a parallel-conversion-type analog-to-digital converter is uncertain. If the comparator offset voltage is large, the parallel-conversion-type analog-to-digital converter may even have a functional error. The comparator offset voltage self-correction circuit provided in the present invention can correct a random offset voltage of a comparator to meet requirements. Therefore, by means of the circuit and a method provided in the present invention, adverse influence of the random offset of the comparator on the function and the performance of the parallel-conversion-type analog-to-digital converter is eliminated, thereby greatly improving the speed and the performance of the analog-to-digital converter, in particular the parallel-conversion-type analog-to-digital converter.

Comparator offset voltage self-correction circuit

A track and hold circuit comprises an input buffer amplifier, a unit gain amplifier module, a sampling switch, a drive triode and a sampling capacitor. The input buffer amplifier receives an input signal. In a track phase, the sampling switch is electrically connected to an emitter electrode of the drive triode; the input signal charges the sampling capacitor after being buffered by the input buffer amplifier, amplified without distortion by the unit gain amplifier module and driven by the drive triode. In a hold phase, the sampling switch is electrically connected to a base electrode of the drive triode; the base voltage of the drive triode is pulled down until the drive triode is cut off; electrical charges on the sampling capacitor are thereby held, causing the signal to be held on the sampling capacitor.

Track and hold circuit

A band-gap reference circuit includes a proportioned current generating circuit, a startup circuit, a current mirror circuit, a high-order temperature compensation generating circuit and a reference generating circuit. The proportioned current generating circuit is configured to generate a current in direct proportion to the absolute temperature. The startup circuit is configured to start up the proportioned current generating circuit when the startup circuit is power on. The current mirror circuit is configured to reproduce a current which is the same as the current in direct proportion to the absolute temperature. The high-order temperature compensation generating circuit is configured to generate a compensation current of high-order temperature coefficient. The reference generating circuit is configured to add the voltage which is generated by the proportioned current generating circuit to a voltage of negative temperature coefficient according to a certain proportion, and output a reference voltage of zero temperature coefficient.

Band-gap reference circuit based on temperature compensation

A high-linearity CMOS input buffer circuit is provided for neutralizing non-linearity of follower circuits' transconductance and output impedance resulting from input signals' variation. In doing so, the linearity of CMOS input buffer is improved. The buffer circuit includes a CMOS input follower circuit, a linearity improvement circuit of follower transistor, a current source load, and a linearity improvement circuit of load impedance. The buffer circuit is fabricated in standard CMOS process, featuring low cost, simplicity and strong linearity at high frequency. It has wide applications in analog and hybrid analog-digital CMOS ICs requiring high linearity input buffer.

CMOS input buffer circuit

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Chongqing, China

Rong-Ke Ye