Power-On Reset Circuit
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
An improved monitor/protection circuit, i.e., a power-on reset circuit (POR), (Fig. 1) is described which not only monitors electronic logic supply voltage and the operation of a pair of microprocessors but simultaneously controls and protects high current circuits in associated input/output devices, such as a printer card. It disables the high (Image Omitted) current electronics in the event of either a voltage drop or a processor software reset. In either case, the processor electronics are in an unknown state which could cause damage. POR also generates power on reset signals for the respective processors. For purposes of this article, it will be assumed that POR disables a motor control driver and a print head driver in the event of a supply voltage failure or a processor failure.