HM

H. Ma

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3 records found

Conference paper (2026) - Heng Ma, Huajun Zhang, Qinwen Fan
Floating-Gm-based current sensors are effective in rejecting PWM common-mode voltage. But their linearity drops at high voltages due to substrate-current-induced body effect in LDMOS devices. To address this issue, this work introduces a DLL-assisted dynamic body biasing sensor in 0.18μm BCD, improving HD2 by 31dB and THD+N by 14dB. And a peak THD+N of -82.3dB is achieved in the meanwhile. It supports 60V common-mode, rejects PWM up to 2MHz, and enables high-linearity sensing for high power audio and motor-driver systems. ...
Conference paper (2025) - H. Ma, S. Karmakar, H. Zhang, Y. Liu, H. Guo, M. Berkhout, Q. Fan
This paper presents a test structure for a 27 mΩ diffusion current sensing resistor, designed to analyze distortion caused by self-heating in audio power amplifiers. A parallel Kelvin connection minimizes parasitic effects, reducing resistance error to 0.4% and temperature coefficient error to 0.7%. A diode-based temperature sensor array enables accurate measurement of temperature variations, allowing the characterization of HD3 with an inaccuracy of ...
Conference paper (2025) - Heng Ma, Huajun Zhang, Marco Berkhout, Qinwen Fan
This paper presents a cost-effective, fully-integrated shunt-resistor-based in-line current sensor offering high linearity and effective PWM rejection for audio applications. To mitigate the on-chip shunt resistor self-heating, which could severely compromise the linearity of the current sensor, a thermal compensation method is proposed and improves the THD+N by up to 23.6 dB. A floating Gm stage is proposed to reject highfrequency high-voltage (HV) PWM signals at the audio amplifier switching node. Implemented in a 180 nm BCD process, the prototype achieves a peak THD + N of -87.2 dB and a DR of 89.1 dB with up to 2 MHz, 14.4 ...