Ultra-low power transmit/receive ASIC for battery operated ultrasound measurement systems

Abstract

AbsractThis paper describes the design of the complete transmit and receive electronics circuitry for a piezoelectric transducer in one single ASIC. The chip will be one building block in a thumb size battery operated ultrasound measurement system. The main design target has been to achieve extremely low power consumption while keeping the number of external components minimal.To overcome the dynamic range limitations imposed by a battery supply an on-chip boost converter uses one external inductor to generate up to 40 V for excitation of the transducer. The transducer itself is used as a storage capacitor, whereafter it is rapidly discharged to generate an ultrasound pulse. An on-chip amplifier with intermittent operation is controlled by a state machine and used to amplify incoming echoes. The chip has been fabricated in a 0.8 m high voltage CMOS process, with a total chip area of 12 mm 2 . Measurements verify the design approach. The power consumption for the system reaches within a factor of 2 of the power needed to charge the capacitance of the piezoelectric transducer from a fixed voltage source. The results show the possibility to achieve extremely low power consumption in a battery operated pulse-echo ultrasound measurement system.

Anemometer 3D Based on Ultrasound

“…In order to excite the transducer with one pulse, it is necessary a relatively high voltage (JOHANSSON et al, 2006), (MAIA, 2001), (NASCIMENTO, 2003). So, the circuit of figure 4 was used to obtain a pulse of 30V approximately on T1.…”

3J-3 Reciprocal Operation of Ultrasonic Transducers: Experimental Results

“…An ASIC from an earlier project is used as a very fast highvoltage transistor with an integrated driver [4]. The output transistor can withstand supply voltages of up to 40 V and the saturation current is 2 A.…”

“…Using custom built electrical transducer interfaces we show improvements in the zero-flow error in 9 cases out of 10, and considerably reduced sensitivity to unequal capacitive loading. The presented work is a part of our ongoing research on integrated electronics for ultrasonic measurement systems [4], [5].…”

Relative ultrasound energy measurement circuit

“…There is a drive to make these systems small, mobile, wireless, internet connected and battery operated. One step on the way to decrease the system size and power consumption is to develop electronics, custom made to be integrated close to the ultrasound crystal [1] [2] [3] [4] [5]. A thumb size wireless platform could be used for data processing, communication, and online presentation of measurement data [6] [7].…”

“…One possible system block diagram can be seen in Figure 1. Here the blocks circumferenced by the dashed line is presented in [5] and the microprocessor system circumferenced by the dash-dotted line is presented in [6]. The energy estimation can also be divided into two blocks, as illustrated in Figure 2.…”