A Four-Channel Analog Front-End ASIC for Wearable A-Mode Ultrasound Hand Kinematic Tracking Applications

This paper presents the design of a four-channel analog front-end ASIC for a wearable A-mode ultrasound hand kinematic tracking system. The system uses ultrasound to record and decode forearm muscle morphology for controlling a prosthetic hand. The design of the wearable system will be in the form of a custom-built bracelet with eight analog front-end/piezoelectric transducer pairs embedded throughout its circumference. The ASIC has four analog front-end channels, each comprising a pulser for driving the transducers, a transmit/receive switch for isolation/protection and a programmable gain amplifier. The ASIC was implemented in a 0.18 µm HV BCD process. Measurements show that the pulser can drive a 130-pF capacitive load with 30 Vpp square pulses at 1 MHz. The programmable gain amplifier can support three gain levels (9.54 dB, 15.56 dB, 21.58 dB) and consumes 1.74 mW. Acoustic experiments demonstrate successful ASIC operation in both the transmit and receive modes.