The Pulse Width Modulator ASIC for Deep Space Missions

*The Jet Propulsion Laboratory has started the development of a P ulse Width Modulator Application Specific Integrated Circuit (PWMA). This development is leveraging the previous development of the Switch Control ASIC (SCA). The purpose of the development is to provide the control for a selected range of power converter topologies and to meet the stringent environmental requirements of deep space missions. The PWMA will include several power control functions that are not normally included on the off -the -shelf components available today. One key functional requirement is the ability to implement an N + K redundant power converter with the ability to control the charging of a battery. Other applications will be the typical point of load isolated and non -isolated power converters. The purpose of the development is not only t o provide a much needed flight part, but also to accelerate the engineering process by using a standard cell library from previous ASIC developments. Under previous developments with Boeing and Lockheed Martin, JPL has produced three ASICs. Each ASIC has b een implemented by using an analog standard cell library. One such development was the SCA, which is design to provide a floating power switch control. The functional verification of this ASIC has been completed and the cells used have been targeted for th e new development of the PWMA. The primary function of the PWMA is to provide the control function of a point of load power converter. The design is an isolated 60 W converter with a 3.3 V output. In architecting the design, several functions were left up to the power -converter designer to make the ASIC more generic. The ASIC can be used for several power converter topologies and power levels. Some additional features have been added to the ASIC to provide the interfaces for multi -phase topologies and batte ry control functions. An N+K fault tolerant strategy has been implemented in order to provide the battery control functions. The PWMA has been developed to provide an ASIC with several functions not normally available in the off the shelf controllers. Thes e functions have been added to enable the power converter designers to achieve fault tolerant designs and battery control functions.