- document
-
Jouvaeian, Amirhossein (author), Fan, Q. (author), Motz, Mario (author), Ausserlechner, Udo (author), Makinwa, K.A.A. (author)Magnetic current sensors are widely used in applications where galvanic isolation and wide bandwidth (BW) are desired, such as in switched-mode power supplies and motor drivers. By using Hall plates for low frequencies and pick-up coils for high frequencies, hybrid magnetic sensors can achieve high resolution (tens of textmA) over a wide...conference paper 2023
- document
-
Tang, Z. (author), Pan, S. (author), Makinwa, K.A.A. (author)BJT-based temperature sensors are widely used because they can achieve excellent accuracy after 1-point calibration. However, they typically dissipate mu textWs of power and require supply voltages above 1V [1]. Although sensors based on DTMOSTs [2], [3], capacitively biased (CB) diodes and BJTs [4,5] have demonstrated sub-1V operation, this...conference paper 2023
- document
-
Yue, X. (author), Javvaji, L.S. (author), Tang, Z. (author), Makinwa, K.A.A. (author), Du, S. (author)Synchronized bias-flip rectifiers, such as synchronized switch harvesting on inductor (SSHI) rectifiers, are widely used for piezoelectric energy harvesting (PEH) [1], which can replace the use of batteries in many loT applications, thus reducing both system volume and maintenance cost. However, the output power extracted by such rectifiers...conference paper 2023
- document
-
Zhang, H. (author), Berkhout, Marco (author), Makinwa, K.A.A. (author), Fan, Q. (author)Class-D amplifiers (CDAs) are widely used in audio applications where a high power efficiency is required. As most audio sources are digital nowadays, implementing digital-input CDAs results in higher levels of integration and lower cost. However, prior open-loop digital-input CDAs suffer from high jitter sensitivity and output-stage...conference paper 2023
- document
-
Toth, N.G. (author), Tang, Z. (author), Someya, T. (author), Pan, S. (author), Makinwa, K.A.A. (author)BJT-based temperature sensors are widely used due to their high accuracy over a wide temperature range with a low-cost 1-point trim. Although resistor-based sensors can achieve better energy efficiency, they typically require a 2-point trim to achieve comparable accuracy, while thermal-diffusivity based sensors achieve superior accuracy at...conference paper 2023
- document
-
Tang, Z. (author), Toth, N.G. (author), Brito Zamparette, R.L. (author), Nezuka, Tomohiro (author), Furuta, Yoshikazu (author), Makinwa, K.A.A. (author)Low-cost metal (e.g., PCB trace) shunts can be used to make accurate current sensors (< 1 % gain error) [1-3]. However, their reported maximum operating temperature (85 circC) is not high enough for automotive applications, and at higher temperatures, shunt resistance may exhibit increased drift, especially at high current levels. This...conference paper 2023
- document
-
An, X. (author), Pan, S. (author), Jiang, H. (author), Makinwa, K.A.A. (author)CMOS frequency references based on RC oscillators are usually preferred over bulky crystals in loT applications [1-5]. However, due to the process spread and finite temperature coefficient (TC) of most on-chip resistors, RC oscillators require trimming and temperature compensation to achieve decent accuracy. Enabled by high-resolution...conference paper 2023
- document
-
Rooijers, C.T. (author), Huijsing, J.H. (author), Makinwa, K.A.A. (author)In chopper amplifiers, the interaction between the input signal and the chopper clock can cause intermodulation distortion (IMD). This is due to amplifier delay, which causes signal transitions generated by the input chopper to arrive at the amplifier's output slightly later than the corresponding clock transitions of the output chopper. This...conference paper 2023
- document
-
Javvaji, L.S. (author), Bolatkale, M. (author), Bajoria, Shagun (author), Rutten, Robert (author), Essink, Bert Oude (author), Beijens, Koen (author), Makinwa, K.A.A. (author), Breems, L.J. (author)Advances in CMOS technologies have led to the development of continuous-time ΔΣ modulators (CTDSMs) with GHz sampling rates that achieve better than-100dBc linearity and bandwidths above 100MHz. However, at low frequencies (below 10MHz), their SNDR is limited by 1/f noise, which limits their use in radio receivers intended to cover both the...conference paper 2023
- document
-
Brito Zamparette, R.L. (author), Makinwa, K.A.A. (author)This paper presents a nano-power high-side shunt-based current sensor (CS) that digitizes the voltage drop across an on-chip (±1A) or a lead-frame (±30A) shunt. A TC-tunable ADC reference compensates for the shunts' large temperature coefficient (TC), resulting in ±0.5% gain error from -40 to 85°C. The CS employs a capacitively coupled gm...conference paper 2023
- document
-
Lu, T. (author), Chang, Z.Y. (author), Jiang, Junmin (author), Makinwa, K.A.A. (author), Du, S. (author)Dual-output regulating rectifier is highly desired in wireless power transfer (WPT) for sub-100mW bioimplants. Such rectifiers perform voltage rectification and dual-output regulation simultaneously, thus avoiding post DC-DC conversions and cascaded power losses [1 –4]. However, the conventional dual-output structure suffers from a low voltage...conference paper 2023
- document
-
Someya, T. (author), Van Hoek, Vincent (author), Angevare, J. (author), Pan, S. (author), Makinwa, K.A.A. (author)This paper presents a 210nW BJT-based temperature sensor that achieves an inaccuracy of ±0.15°C (3s) from -15°C to 85°C. A dual-mode front-end (FE), which combines a bias circuit and a BJT core, halves the power needed to generate well-defined CTAT (VBE) and PTAT (?VBE) voltages. The use of a tracking ?S ADC reduces FE signal swing and...conference paper 2022
- document
-
Mehrotra, Shubham (author), Eland, Efraim (author), Karmakar, S. (author), Liu, Angqi (author), Gonen, B. (author), Bolatkale, M. (author), Van Veldhoven, Robert (author), Makinwa, K.A.A. (author)This paper presents a continuous-Time zoom ADC for audio applications. It combines a 4-bit noise-shaping coarse SAR ADC and a fine delta-sigma modulator with a tail-resistor linearized OTA for improved linearity, energy efficiency, and handling of out-of-band interferers compared to previous designs. In 160 nm CMOS, the prototype chip...conference paper 2022
- document
-
Campos de Oliveira, A. (author), Pan, S. (author), Makinwa, K.A.A. (author)Flow sensors with high resolution (<200g/h/surdHz) and low offset drift (<pm 0.4mg/h) are essential in many microfluidic applications, such as flow cytometry and biological/chemical assays. Although thermal flow sensors can meet these specifications [1], [2], they measure flow velocity, so their calibration is fluid specific. Coriolis...conference paper 2022
- document
-
Tang, Z. (author), Brito Zamparette, R.L. (author), Furuta, Yoshikazu (author), Nezuka, Tomohiro (author), Makinwa, K.A.A. (author)Accurate current sensing is critical in many industrial applications, such as battery management and motor control. Precise shunt-based current sensors have been reported with gain errors of less than 1% over the industrial temperature range (-40°C to 85°C) [1]–[4]. However, since they are intended for coulomb counting, their bandwidth is...conference paper 2022
- document
-
Zhang, H. (author), Berkhout, Marco (author), Makinwa, K.A.A. (author), Fan, Q. (author)Class-D amplifiers (CDAs) are often used in audio applications due to their superior power efficiency. Due to the sensitivity of the human ear, a large dynamic range (DR) is desired, and audio DACs with up to 130dB DR are commercially available [1]. However, the DR of the CDAs they drive is typically much lower [2]-[4], mainly due to the...conference paper 2022
- document
-
Karmakar, S. (author), Berkhout, Marco (author), Makinwa, K.A.A. (author), Fan, Q. (author)Piezoelectric speakers are gaining popularity on account of their improving form-factor and audio quality, making them a good fit for many audio applications such as in televisions, laptops, etc. Such speakers can be modelled as a large capacitive load, and so are typically driven by a Class-AB amplifier via a series resistor that ensures driver...conference paper 2022
- document
-
Rooijers, C.T. (author), Karmakar, S. (author), Kusuda, Yoshinori (author), Huijsing, J.H. (author), Makinwa, K.A.A. (author)Amplifiers often employ chopping to achieve low offset and low-frequency noise. However, the interaction between the input signal and the chopper clock can cause chopper-induced intermodulation distortion (IMD) [1] -[5]. This is especially problematic for input frequencies (Fin) near even multiples of the chopping frequency (FCH), as the...conference paper 2021
- document
-
Angevare, J. (author), Chae, Youngcheol (author), Makinwa, K.A.A. (author)Microprocessors and SoCs employ multiple temperature sensors to prevent overheating and ensure reliable operation. Such sensors should be small (<10,000μm2) to monitor local hot-spots in dense layouts. They should also be moderately accurate (1°C) up to high temperatures (≥125°C), so that the system throttling temperature can be set as...conference paper 2021
- document
-
Choi, Woojun (author), Angevare, J. (author), Park, Injun (author), Makinwa, K.A.A. (author), Chae, Youngcheol (author)Wireless sensor nodes in battery-powered internet-of-things (loT) applications require a stable on-chip frequency reference with low energy (<10 pJ / cycle) and high frequency stability (below ±300ppm). CMOS RC frequency references are promising due to their low-cost integration and high energy efficiency [1] –[5]. Conventional RC references,...conference paper 2021