Here is the abstract you requested from the HiTEC_2012 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|VEGA & RIGEL: New Tiny High Temperature Adjustable Voltage Regulators for Reduced PCB Footprint and Extended Reliability of Medium and High Temperature Systems|
|Keywords: High Temperature Electronics, Low dropout linear regulator, Thermal resistance|
|In high temperature applications, PCB footprint and weight are critical aspects. While SMPS are solutions of choice for current needs above 1A, lower current requirements in the order of a few hundreds of mA are more looking for linear regulation with tiny devices to be used in multiple instances within the systems. However, and as voltage regulators see their operating junction temperature elevated due to self-dissipation, the lifetime often becomes problematic when using traditional silicon regulators. To address these concerns, CISSOID has designed two new adjustable linear voltage regulators delivered in a tiny ceramic SMD package (5.5x5mm). This paper will present how these circuits are optimized from both size and thermal characteristics standpoints. CHT-VEGA can regulate a 5V ±10% input voltage to an adjustable 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 will be 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.|
|Jean-Christophe Doucet, VP Marketing & Business Development
Mont-Saint-Guibert, Brabant Wallon