VEGA & RIGEL: New tiny high temperature adjustable voltage regulators for reduced PCB footprint and extended reliability of medium and high temperature systems

Abstract

This paper presents two new tiny high-temperature adjustable voltage regulators. CHT-VEGA can regulate a 5V ±10% input voltage to an output within the range 1.1V to 3.6V and delivering up to 500mA at 225°C (junction). The output voltage is set by an external resistor divider and is maintained within +/−5% total accuracy in all load, line and temperature conditions. The second device, CHT-RIGEL, supports a wide input voltage range up to 30V; its output is adjustable between 1.8V and 24V, with up to 100mA capability at 225°C. Both chips feature a thermal shut-down with a threshold in the 250∼300°C range: the first over-temperature protection of this kind in high temperature devices. CISSOID created a new TDFP SMD package that combines tiny size and good thermal resistance. A detailed thermal characterization is presented, as well as what it means for the operating temperature, and the impact on PCB footprint and system cost. As a conclusion, will be highlighted the benefits of using such ICs rated 225°C at junction level, even if the ambient temperature of the application remains low (e.g. 175°C), and in particular the impact on reduction of the PCB footprint, compared to 175–210°C ratings.