July 2005, Issue 180

Solar-Powered Water Pump Controller
Cypress PSoC High Integration Challenge 2004 Contest Winner

OVER-CURRENT DETECTOR

In addition to measuring the maximum DC current with the ADC, it’s also monitored for excessive levels. This is done with a programmable threshold comparator block, which is directly connected to the incoming analog signal via pin P0[6]. The output from the comparator disables the PWM generators using the dead-band kill function, which enables high-speed shutdown without intervention from the main processor. The synchronous Shutdown mode kills the remaining switching cycle and restarts the PWM generation on the next cycle.