All PSoC Application Notes

AN2154: Voltage Monitoring and Sequencing with PSoC

Many systems require a variety of voltages to power the ASICs, FPGAs, and standard logic found in today's designs. To further complicate the design, some of these devices require voltages to power on in a specific sequence, lest damage to the chip will occur. There are a variety of voltage monitoring and sequencing devices available today. However, they can be expensive and often don't meet the needs of the design since they offer little or no programmability. PSoC is an excellent choice for monitoring and sequencing the voltages. With its analog structure and programmability, the PSoC can be a perfect fit for the most stringent designs. This Application Note describes a system that uses eight different voltages. The PSoC monitors each of the eight rails and controls the voltage-enables such that they power on in sequence. Subsequent rails are activated only after the previous rail rises to a minimal voltage level. All the voltages are constantly monitored and if any voltage falls below a minimum value, the appropriate enables are turned off. The configuration can be easily adapted to satisfy other designs.