21:T4b3,A sensor interface circuit based on impulse radio pulse width modulation (IR-PWM) is presented for low power and high throughput wireless data acquisition systems (wDAQ) with extreme size and power constraints. Two triple-slope analog-to-time converters (ATC) convert two analog signals, each up to 5 MHz in bandwidth, into PWM signals, and an impulse radio (IR) transmitted (Tx) with an all-digital power amplifier (PA) combines them while preserving the timing information by transmitting impulses at the PWM rising and falling edges. On the receiver (Rx) side, an RF-LNA followed by an envelope detector recovers the incoming impulses, and a T-flipflop reverts the impulse sequence back to PWM to be digitized by a time-to-digital converter (TDC). Detailed analysis and design guideline on ATC was introduced, and a proof-of-concept prototype was fabricated for a capacitive micromachined ultrasound transducer (CMUT) imaging system in a 0.18-μm HV CMOS process, occupying 0.18 mm² active area and consuming 3.94 mW from a 1.8 V supply. The proposed TDC in this prototype yielded 7-bit resolution, while the entire wDAQ achieved 5.8 effective number of bits (ENOB) at 2 × 10 MS/s.22:T4ba,A power-efficient bridge-to-digital sensing interface is proposed, which also offers immunity against power supply noise. The interface utilizes duty-cycling to reduce the static power consumption of resistive bridge sensors, which are commonly used in implantable, wearable, and internet of things (IoT) applications, such as intracranial pressure (ICP) sensing and blood pressure (BP) monitoring. The proposed interface uses a revised version of the pseudo-pseudo differential (PPD) topology with the ping-pong technique to reduce the complexity of traditional fully-differential counterparts. A proof-of-concept prototype has been fabricated in 0.35-μm CMOS and occupies an active area of 0.48 mm². It achieves 9.13 effective number of bits (ENOB) at 3.72 kHz sampling rate and improvement of more than 50 dB in the power supply rejection ratio (PSRR) by employing the ping-pong technique. It reduces the power consumption of a 5-kΩ Wheatstone bridge by 99.6% compared to a traditional interface, down to 2.53 μw at 1.8 V supply. The functionality of the system has also been demonstrated in an experimental setup in conjunction with an embedded resistive bridge pressure sensor.23:T674,

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