Toshiba Develops a Wide-Input-Voltage-Range High-Efficiency Switched-Capacitor DC-DC Converter for Wireless IC

Many of today’s wireless ICs have embedded DC-DC converters instead of LDO regulators to reduce the power consumption of the ICs. However, mainstream inductor-based DC-DC converters require an inductor that is relatively bulky and expensive. Capacitor-based DC-DC converters have gained attention recently on their ability to offer a compact, low cost module. However, switched-capacitor DC-DC converters offer high efficiency only in a limited input and output voltage range, since they are based on a discrete conversion ratio; inductor-based DC-DC converters have a continuous conversion ratio. Conventional techniques solve this by connecting multiple switched-capacitor units in series, but this incurs an efficiency penalty.

Toshiba has solved the issue by developing a new unified switched-capacitor topology with 3 capacitors and a multiple switch control architecture, that achieves multiple conversion ratios. Switched between the appropriate configurations of capacitors, this switched-capacitor DC-DC converter offers up to 95.8% efficiency with a 0.85-to-3.6V wide input voltage range, and a 0.1-to-1.9V wide output voltage range. It also supports auto-configured step-up and step-down power conversions, and can provide 2 channels of regulated output voltages.