New regulated voltage down converter based on modified band-gap cells

A new simple on-chip regulated voltage-down-converter (VDC) is presented. The VDC output can be advantageously fixed at 2.5V, 3V or 3.5V. The voltage down converter was fabricated in 0.5µm CMOS technology from STMicroelectronics. The circuit provides a typical 3V output with a temperature dependency of only 300µV/°C. At 10mA loading current, the output is always stabilised within ±10% with 4V∼10V supply voltage variations and -40°C∼125°C temperature variations. Including the output power stage the circuit uses only 22 transistors.