Power Up

See function block D of the A6A2 regulator schematic diagram in the component-level information.

The power up circuitry generates the PWR UP signal, which tells the microprocessor that the supplies are up and stable. PWR UP will go high when the +5 Vdc supply exceeds

t4.99 Vdc. PWR UP will go low when this voltage drops below i-4.895 Vdc. Once PWR UP is set low, it will stay low for at least 50 ms before going high, even if the +5 Vdc supply exceeds t4.99 Vdc before 50 ms have elapsed.

13-18 Display/Power Supply Section

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Agilent Technologies 856290216 service manual Power Up