The Power-On Reset (POR) and Over Current Detection (OCD) macro comprehensively addresses typical SOC start-up power supply monitoring needs and over current detection capability, in a fully integrated easy-to-use macro. The POR includes an internal bandgap style voltage reference circuit which is used as a reference to compare the power supplies against. The POR further includes its own timebase reference circuit, so requires no clock or other synchronizing signal to work correctly. Only when both IO and Core power supplies have both exceeded a user-selected voltage level for a user-selected time, will the outputs signal that power is good.
The POR provides outputs at both the IO and core logic levels, with a low level representing a poor or unstable power supply, and a high level representing a good stable power supply. These signals may be used as logical “RSB” or “ENA” signals.
The OCD feature is a Voltage Comparator for Over Current Detection application. Ithas an integrated low- power Bandgap reference and programmable hysteresis levels. The OCD outputs will flag an output High in response to detecting an external voltage higher than the internal reference, plus a selected hysteresis amount.