| Title |
Noise-Immune Current Sensor Using a Shunt Resistor |
| Authors |
Myeong-Ho Kim ; Jong-Hun Kim ; Seung-Ju Lee ; Yeon-Woo Jeong ; Mun-Jung Cho ; Dong-Chan Lee ; Eun-Jae Ko ; Min-Gyu Jeong ; Geon Kim ; Min-Su Kim ; Se-Un Shin |
| DOI |
https://doi.org/10.6113/TKPE.2026.31.5.376 |
| ISSN |
1229-2214(pISSN), 2288-6281(eISSN) |
| Keywords |
Peak Current Mode Control; Shunt Resistor Current Sensor; Common-Mode Noise Immunity |
| Abstract |
This paper introduces a differential current-sensing architecture that uses a shunt resistor to enhance noise immunity in peak current-mode control switching converters. Conventional single-ended structures are sensitive to common-mode noise due to PCB parasitic impedance and high di/dt switching transitions, causing gain errors, nonlinearity, and false triggering. The proposed architecture independently extracts both nodes of the shunt resistor and processes the signals differentially. Low-pass filtering is employed to suppress switching spikes, while a folded-cascode amplifier with cascode current mirrors offers high gain and accurate current replication. Simulations under ideal conditions, parasitic inductance, and combined parasitic-plus-noise conditions confirm that the proposed structure maintains a gain close to the designed value of 11. Results indicate substantially improved linearity and output accuracy compared with single-ended sensing, making the proposed architecture suitable for high-speed switching environments. |