Semiconductor Manufacturing International (beijing) Corporation

Semiconductor Manufacturing International (shanghai) Corporation

Qingyang Wu

Jun Zhu

Wenzhe Luo

Jiaqing Wang

Liwu Yang

Yunxiang Peng

Yangyuan Wang

A demodulation circuit for an Amplitude Shift Keyed (ASK) modulated signal includes an envelope detector, an alternating voltage amplifier, a differentiator circuit, and a comparator having a hysteresis connected in series. The envelope detector produces an envelope signal from the received ASK signal. The amplifier blocks the DC component of the envelope signal and amplifies AC components of the envelope signal to obtain a steeper slope of the rising and falling edges. The differentiator circuit then processes the transition edges to provide a differentiated signal having positive and negative electrical pulses. The comparator converts the pulses into a binary data stream which corresponds to the transmitted data stream. The combination of the differentiated signal and comparator having a hysteresis enables better stability and sensitivity of the ASK demodulation circuit.

Amplitude shift keyed (ASK) demodulation pattern and use in radio frequency identification (RFID)

A charge pump circuit includes a switch unit adapted to transmit charges from the input of the charge pump to the output of the charge pump; a transmission unit adapted to control turn-on or cut-off of an MOS transistor in the switch unit; and a charging unit in one-to-one correspondence with a PMOS transistor in the switch unit and adapted to store charges to boost the transmission voltage. A first NMOS transistor and at least two PMOS transistor are used as the switch unit during transmission of the charges, so that normal work can be enabled with high transmission efficiency in the case of a low source voltage.

Charge pump circuit

Growing community of inventors

Shanghai, China

Qingyang Wu