Abstract:
A capacitive trans-impedance amplifier comprising a voltage amplifier having an inverting input terminal for connection to an input current source. A feed-back capacitor is coupled between the inverting input terminal and the output terminal to accumulate charges received from the input current source and to generate a feed-back voltage accordingly. A calibration unit includes a calibration capacitor electrically coupled, via a calibration switch, to the inverting input terminal and electrically coupled to the feed-back capacitor. The calibration unit is operable to switch the calibration switch to a calibration state permitting a discharge of a quantity of charge from the calibration capacitor to the feed-back capacitor. The capacitive trans-impedance amplifier is arranged to determine a voltage generated across the feed-back capacitor while the calibration switch is in the calibration state and to determine a capacitance value (C=Q/V) for the feed-back capacitor according to the value of the generated voltage (V) and the quantity of charge (Q).
Abstract:
A MEMS sensor (1) comprises a MEMS transducer (10) being coupled to a MEMS interface circuit (20). The MEMS interface circuit (20) comprises a bias voltage generator (100), a differential amplifier (200), a capacitor (300) and a feedback control circuit (400). The bias voltage generator (100) generates a bias voltage (Vbias) for operating the MEMS transducer. The variable capacitor (300) is connected to one of the input nodes (I200a) of the differential amplifier (200). At least one of the output nodes (A200a, A200b) of the differential amplifier is coupled to a base terminal (T110) of an output filter (110) of the bias voltage generator (100).Any disturbing signal from the bias voltage generator (100) is a common-mode signal that is divided equally on the input nodes (I200a, I200b) of the differential amplifier (200) and is therefore rejected.
Abstract:
The invention relates to a device for operating a passive infrared detector (PIR). The passive infrared detector (PIR) is discharged by means of a discharging network (RG) during charging and preferably not during the measurement. The discharging network (RG) and the infrared detector (PIR) are connected to an analog-to-digital converter (ADC), which converts the signal of the infrared detector into a digital signal on the output bus T at least at times. The output (T) of the analog-to-digital converter (ADC) is connected to a subsequent digital filter (DF). The bus bandwidth of the output (Out) of the digital filter (DF) is typically greater than the bus bandwidth of the output (T) of the analog-to-digital converter (ADC).
Abstract:
본 발명은 캐스코드 연결된 한 쌍의 PMOS 트랜지스터의 각각의 게이트 사이와, 캐스코드 연결된 한 쌍의 NMOS 트랜지스터의 각각의 게이트 사이에 부트스트랩 캐패시터를 설치하고, 데이터 샘플링 단계(Φ 1 )에서는 전류기근을 통해 PMOS 트랜지스터와 NMOS 트랜지스터를 모두 약반전 동작시켜 부트스트랩 캐패시터에 입력 전압(V IN )과 기준전압(V BP , V BN ) 사이의 전위차에 대응된 전하를 저장하였다가, 전하전달 단계(Φ 2A )에서는 입력전압이 극성에 따라 NMOS 트랜지스터 쌍 또는 PMOS 트랜지스터 쌍 중 어느 한 쌍을 강반전으로 구동하고 다른 한 쌍은 컷오프 동작하도록 하여 넓은 대역폭을 확보하도록 하고, 전하전달 후 정상상태 단계(Φ 2B )에서는 PMOS 트랜지스터와 NMOS 트랜지스터를 모두 약반전 회귀시켜 높은 이득과 함께 전력소모를 방지하는 방식을 제공한다.
Abstract:
El circuito objeto de la presente invención está orientado a su uso en amplificadores de carga, proporcionando una estabilización continua de su punto de operación. La invención es especialmente apropiada para circuitos integrados, en los que la realización de resistencias de alto valor es costosa en área, e introduce parásitos importantes. Mediante el circuito objeto de la presente invención se ha demostrado la posibilidad de construir resistencias de más de 100 gigaohmios. Campos específicos de aplicación son: sensores microelectromecánicos capacitivos, transductores ópticos y piezoeléctricos, y en cualquier aplicación que requiera la medida de carga acumulada o la integración de corriente eléctrica. La invención es igualmente adecuada para su realización en circuitos integrados que necesiten constantes de tiempo muy largas, como integradores o filtros analógicos.
Abstract:
Systems, methods, and integrated circuits employ switch capacitor technology for digital to analog conversion. In one embodiment a DAC receives a multi-bit digital signal. The DAC has a switch capacitor network with a plurality of sub DACs. Each of the sub DACs receives an associated bit of the multi-bit digital signal. The capacitance within each of the sub DACs receives an amount of charge in response to the associate bit. At least two of the sub DACs share charge with one another, and the network outputs at least one analog signal indicative of a sum of values of each bit in the multi-bit digital signal.