TY - JOUR
T1 - Self-Regulated Reconfigurable Voltage/Current-Mode Inductive Power Management
AU - Gougheri, Hesam Sadeghi
AU - Kiani, Mehdi
N1 - Publisher Copyright:
© 2017 IEEE.
PY - 2017/11
Y1 - 2017/11
N2 - A reconfigurable power management structure for inductive power delivery has been proposed by adaptively employing either resonant voltage or current mode (VM or CM) to improve the inductive power transmission performance against coils' coupling distance (d), orientation (φ), and load impedance (RL) variations. At the presence of these variations, unlike conventional VM and CM power managements with poor voltage- and power-conversion efficiencies (VCE and PCE), respectively, the proposed voltage/current-mode inductive power management (VCIPM) chip can achieve high VCE by automatically switching to CM when the receiver (Rx) coil voltage (VR) is smaller than the required load voltage (VL), and achieve high PCE by operating in VM when VR > VL. In addition, since VM and CM are only suitable for small and large RL within the range of hundreds of ohms and above, respectively, the VCIPM chip can extend the RL range. The VCIPM chip also eliminates the need for two off-chip capacitors by performing rectification, regulation, and over-voltage protection (OVP) in one step with one off-chip capacitor. In VM, intentional reverse current is employed for both voltage regulation and OVP, while the Rx coil switching frequency (fsw) is adjusted for voltage regulation in CM. The theory behind the proposed VCIPM structure has been presented and validated by simulations and measurements. A VCIPM prototype chip was fabricated in a 0.35-μm 2P4M standard CMOS process occupying 0.52-mm2 active area. In measurements, the VCIPM chip, operating at 1 MHz, achieved a high VCE of 4.1 V/V for RL of 100 kΩ by operating in CM with fsw = 166.6 kHz, and extended d and φ from 6 to 13.5 cm (125%) and 30° to 75° (150%), respectively, compared to its VM counterpart by adaptively switching from VM to CM.
AB - A reconfigurable power management structure for inductive power delivery has been proposed by adaptively employing either resonant voltage or current mode (VM or CM) to improve the inductive power transmission performance against coils' coupling distance (d), orientation (φ), and load impedance (RL) variations. At the presence of these variations, unlike conventional VM and CM power managements with poor voltage- and power-conversion efficiencies (VCE and PCE), respectively, the proposed voltage/current-mode inductive power management (VCIPM) chip can achieve high VCE by automatically switching to CM when the receiver (Rx) coil voltage (VR) is smaller than the required load voltage (VL), and achieve high PCE by operating in VM when VR > VL. In addition, since VM and CM are only suitable for small and large RL within the range of hundreds of ohms and above, respectively, the VCIPM chip can extend the RL range. The VCIPM chip also eliminates the need for two off-chip capacitors by performing rectification, regulation, and over-voltage protection (OVP) in one step with one off-chip capacitor. In VM, intentional reverse current is employed for both voltage regulation and OVP, while the Rx coil switching frequency (fsw) is adjusted for voltage regulation in CM. The theory behind the proposed VCIPM structure has been presented and validated by simulations and measurements. A VCIPM prototype chip was fabricated in a 0.35-μm 2P4M standard CMOS process occupying 0.52-mm2 active area. In measurements, the VCIPM chip, operating at 1 MHz, achieved a high VCE of 4.1 V/V for RL of 100 kΩ by operating in CM with fsw = 166.6 kHz, and extended d and φ from 6 to 13.5 cm (125%) and 30° to 75° (150%), respectively, compared to its VM counterpart by adaptively switching from VM to CM.
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U2 - 10.1109/JSSC.2017.2737138
DO - 10.1109/JSSC.2017.2737138
M3 - Article
AN - SCOPUS:85028545430
SN - 0018-9200
VL - 52
SP - 3056
EP - 3070
JO - IEEE Journal of Solid-State Circuits
JF - IEEE Journal of Solid-State Circuits
IS - 11
M1 - 8016565
ER -