High-Temperature Versatile Voltage-Mode PWM Controller

Abstract

In this paper we present the operation of the XTR30011 device, a high-temperature, versatile, PWM controller with in-specification performance achieved from −60°C to 230°C using a CMOS SOI process. The circuit features a voltage-mode PWM controller that can be used in Buck-mode converters as well as in Boost, Buck-boost, Push-pull and Flyback. Several functional features are implemented including duty-cycle limitation allowing cycle-by-cycle current limitation, hiccup short-circuit protection and complex functionalities for improved efficiency at low load currents. These advanced features for improved efficiency include automatic synchronous-asynchronous mode transition in Buck-mode, pulse skipping logic with adjustable threshold, low-power mode with capability to receiving the 5V converter output voltage. Efficiency in DC-DC converters operated at low load currents is dominated by switching as well as intrinsic consumption losses. The XTR3011, in addition to having a low intrinsic current consumption, allows reaching very good efficiencies at low load currents thanks to its functional features. We present here the operation of several functional features and experimental results across temperature of the efficiency in several configuration modes, and in particular for low load currents.