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In a system including volatile memory, a battery backed memory may be available for preserving data in the event of a power failure. Low power condition is reliably sensed sufficiently in advance of supply voltage falling below a minimum operating voltage range so as to give an adequate time interva

In a system including volatile memory, a battery backed memory may be available for preserving data in the event of a power failure. Low power condition is reliably sensed sufficiently in advance of supply voltage falling below a minimum operating voltage range so as to give an adequate time interval, e.g. 2.5 milliseconds for the saving of application operating system status. By using a voltage regulator signal which switches in a particularly sensitive manner toward a saturation or zero state well outside its normal control range to trigger a low power signal, such low power signal may provide a time interval of, e.g. from three to six milliseconds of advance warning of impending supply voltage failure. The system is particularly useful for hand-held data processing systems with rechargeable batteries since the regulator may provide its regulator signal as a common control signal for regulating multiple supply paths, and may only trigger the low power signal when all of such supply paths approach a failure condition.

대표청구항 ▼

In a system including power supply means for supplying a power supply voltage, automatic voltage regulator means having input means coupled with said power supply means and automatically operable for supplying a regulated output power, said automatic voltage regulator means producing a regulator sig

In a system including power supply means for supplying a power supply voltage, automatic voltage regulator means having input means coupled with said power supply means and automatically operable for supplying a regulated output power, said automatic voltage regulator means producing a regulator signal which progressively changes as a function of a power supply voltage and approaches a limit range as power supply voltage is reduced below a given minimum value, and signalling means coupled with said automatic voltage regulator means for supplying a low power signal to an external circuit when the regulator signal approaches said limit range.