Nxp Usa, Inc.

Freescale Semiconductor,inc.

Nxp B.v.

Yikun Mo

Jie Jin

Jianzhou Wu

Stefano Pietri

Michael Todd Berens

Liang Zhang

Yizhong Zhang

Jiawei Fu

Ashutosh Jain

Jianluo Chen

Hongyan Yao

Sitong Wang

Linhao Cao

A self-calibrated buffered-voltage DAC includes a DAC configured to receive an input digital signal and output a first analog voltage signal, a buffer amplifier configured to receive the first voltage signal from the DAC and provide a buffered second analog voltage signal, a voltage to frequency converter configured to selectively receive the first and second voltage signals and provide first and second output signals at respective first and second frequencies, a counter configured to receive the output signals from the voltage to frequency converter and provide respective first and second digital output signals corresponding to the respective first and second frequencies, a comparator configured to receive the first and second digital output signals and provide a digital calibration offset, and a DAC error code module configured to receive a digital input code and the digital calibration offset and to provide an offset corrected input digital signal to the DAC.

Self-calibrating buffered-voltage DAC

A bias current generator circuit includes a current path and a leakage control circuit. The current path is connected between a supply voltage and a ground level. The current path includes a transistor and a resistor. The transistor has a current channel connected in the current path. The resistor has an upper terminal and a lower terminal connected in the current path, and a well contact to allow a reverse leakage current of the resistor to flow through. The leakage control circuit is connected to the supply voltage. The leakage control circuit includes a driving transistor to provide a driving voltage to the well contact of the resistor, and to allow the reverse leakage current of the resistor to flow into the leakage control circuit.

Bias current generator circuit

An analogue switch arrangement includes an analogue switch including a first and second transistor in parallel between an input terminal and an output terminal and an input transistor arrangement including a first control transistor, a second control transistor, a first voltage control transistor and a second voltage control transistor. The gate terminals of both the first and second transistors are configured to receive a first and second control signal for controlling the analogue switch between an on-state and an off-state. The gate terminals of both the first and second voltage control transistors are configured to receive a voltage based on the voltage at the output terminal to provide for control of the voltage applied at the input terminal based on the voltage at the output terminal when the analogue switch is in the off-state.

Analogue switch arrangement

During a sampling phase, an analog front end circuit connects input of a first sampling capacitor to an analog input signal and input of a second sampling capacitor to a reference signal, and connects first and second hold capacitors to ground. During a partial tracking phase, input of the first sampling capacitor is connected to the reference voltage and the input of the second sampling capacitor is connected to the analog input signal. The first hold capacitor is connected to a first output of a gain amplifier and the second hold capacitor to a second output of the gain amplifier. Output of the first sampling capacitor is coupled to a first input of an amplifier and output of the second sampling capacitor is coupled to a second input of the amplifier.

Analog front-end circuit capable of use in a sensor system

A comparator has an input stage having (i) resistor-coupled super source-follower circuits that convert differential input voltages into differential currents and (ii) hysteresis current-injection circuits that inject hysteresis currents into the differential currents. An output stage processes the differential currents to control the comparator output. Common-mode (CM) detection circuits inhibit some of the differential currents from reaching the output stage if the CM voltage is too close to a voltage rail of the comparator. The comparator is able to operate at CM voltages over the entire rail-to-rail range with constant hysteresis voltage.

Rail-to-rail comparator with built-in constant hysteresis

Growing community of inventors

Suzhou, China

Yikun Mo