Designing Robust Multi - Regulator Power Management Architectures for Automotive SoCs

Abstract

This paper describes the design, pre-Silicon mixed-mode verification and post-Silicon testing of an architecture for a Power Management Controller (PMC) for automotive applications in 40nm CMOS. This PMC supports multiple-regulators and multiple power-saving modes like Standby, Low Power, Reduced Clocking mode, etc. This PMC is also reconfigurable and supports both internal and external regulation for its highest power consuming domain. This is to provide a viable solution to several different customers with different needs, but while ensuring minimal product development costs. In the external regulation mode, one domain is powered by an External Regulator/PMIC, while two other domains are internally regulated. Like how supply monitoring circuits are crucial for the monitoring supplies within a SOC, the External Regulator must provide a supply stability indicator to the SOC. To complicate the situation further, the External Regulator may need to be shut off based on mode transitions being performed within the SOC. Thus, there is a need to create a handshake mechanism between the SOC and the external regulator. We discuss a systematic approach to defining a complex PMC architecture and enabling this handshake mechanism between a multi-mode multi-regulator on-chip PMC with an external power regulator. This PMC architecture is used as part of a 32-bit MCU fabricated in 40nm CMOS. Silicon results are provided.