A LoW-Power Oscillator-Based Readout Interface for Medical Ultrasonic Sensors

 A LoW-Power Oscillator-Based Readout Interface for Medical Ultrasonic Sensors

 An oscillator-based ultrasonic sensor interface that can be applied to intravascular applications. The readout circuits are validated with a capacitive micromachined ultrasonic transducer (CMUT) and a current-to-frequency chip. The CMOS CMUTs are integrated with a current amplifier on the same chip and the current-to-frequency chip provides the current-tofrequency readout interface. Relaxation oscillators with injection locking are employed to achieve low-power consumption. Also, the time-based output signal can be further digitized with a time-todigital converter.