January 2009

ispPAC-POWR607 Power Manager II Device Integrates Multiple Discrete ICs

 A wide variety of power, reset and watchdog timer (WDT) application scenarios have led component suppliers to field a staggering array of discrete digital and mixed-signal components designed to help address the power management of CPU, DSP, and FPGA devices. The variety has been necessary to account for various supply voltage rails, result pulse stretching, and WDT periods required by various processor and FPGA devices. Multiple discrete power management ICs, however, contribute to layout complexity and the cost of a PCB. By merging the features of a CPLD with high accuracy mixed-signal blocks, the ispPAC-POWR607 provides more flexibility and lowers bill of material costs.

Typical Application

The figure below illustrates a common application of the ispPAC-POWR607 in a system chassis, single board computer, or set-top box. The Voltage Supervisor block detects whether any rail of the power supply bus driven from the DC-DC converters are outside the legal range of operation. If the range is violated, it issues a power fail interrupt to the processor so it can gracefully shut down. The reset generator block is commonly required by processors to generate a reset signal for an extended time after all supplies are stable. It is not unusual for this pulse to last up to 2 milliseconds. If the processor or FPGA main program fails to respond regularly (an indication the system has hung), the watchdog timer block triggers a system reset.

The ispPAC-POWR607 is also attractive to system engineers because it offers a low-power mode that draws less than 10uA Icc and a JTAG interface for in system programming. As engineers are pressured to cut costs and improve the reliability of circuit boards, an often overlooked opportunity is to reduce the number of components used for power monitoring. The ispPAC-POWR607 is an ideal solution that combines reset generation, watchdog timer (WDT) and voltage supervisor ICs into a single device.

To Learn More

For further information, visit the Lattice website or contact your local Lattice sales representative.