A High-Voltage Low-Power DC-DC buck regulator for automotive applications

This work presents a High-Voltage Low-Power CMOS DC-DC buck regulator for automotive applications. The overall system, including the high and low voltage analog devices, the power MOS and the low voltage digital devices, was realized in the Austriamicrosystems 0.35 HVCMOS technology, resulting in a 6.5 mm² die. The regulator is able to manage a supply voltage down to 4.5 V and up to 50 V and generates a fixed regulated output voltage of 5 V or a variable one in the whole automotive temperature range. The regulator sinks only a maximum of 1.8 ??A of current in standby mode and a maximum of 25 ??A when no load is connected. It can be used to supply low voltage devices from the battery when low power dissipation and low current consumption is needed. The system output current can be selected in the range 350-700 mA. When a higher output current is needed, it is possible to connect more regulators in parallel multiplying the output current without any problem.