公开(公告)号：US20130162458A1

公开(公告)日：2013-06-27

申请号：US13707198

申请日：2012-12-06

Applicant: Renesas Electronics Corporation

Inventor： Osamu NISHIKIDO ,  Yasutoshi AIBARA ,  Hirokazu SHIMIZU ,  Satoshi TATSUKAWA ,  Takayoshi SHIGEKURA

IPC: H03M1/50

CPC classification number: H04N5/378 ,  H03M1/0863 ,  H03M1/123 ,  H03M1/50 ,  H03M1/56 ,  H04N5/3577 ,  H04N5/374

Abstract: There is a need to provide an AD converter capable of reducing occurrence of a noise. An AD converter includes an operational amplifier and a clip circuit. The operational amplifier receives ramp voltage and voltage for an analog signal and allows output terminal voltage to transition from an H level to an L level when a change in the ramp voltage reaches the voltage for the analog signal. The clip circuit fixes an output terminal of the operational amplifier to clipping voltage after output voltage for the operational amplifier reaches threshold voltage for a latch circuit. Therefore, the AD converter can limit a range of output voltage, as a source of noise, for the operational amplifier and eliminate an unnecessary change in the output voltage after the threshold voltage for the latch circuit is reached.

Abstract translation: 需要提供能够减少噪声发生的AD转换器。 AD转换器包括运算放大器和钳位电路。 当斜坡电压的变化达到模拟信号的电压时，运算放大器接收模拟信号的斜坡电压和电压，并允许输出端电压从H电平转换到L电平。 钳位电路在运算放大器的输出电压达到锁存电路的阈值电压之后，将运算放大器的输出端固定为钳位电压。 因此，AD转换器可以限制作为运算放大器的噪声源的输出电压的范围，并且在达到锁存电路的阈值电压之后消除输出电压的不必要的变化。