TL7700A Datasheet | STMicroelectronics

® TL7700A Series SUPPLY VOLTAGE SUPERVISORS - . . POWER-ON RESET GENERATOR AUTOMATIC RESET GENERATION AFTER VOLTAGE DROP WIDE SUPPLY VOLTAGE RANGE ... 3V TO 18V PRECISION VOLTAGE SENSOR TEMPERATURE-PENSATED VOLTAGE REFERENCE TRUE AND PLEMENT RESET OUTPUTS EXTERNALLY ADJUSTABLE PULSE WIDTH N Min idip DESCRIPTION The TL7700Aseriesaremonolithicintegratedcircuit supplyvoltagesupervisorsspecifically desi-gnedfor use as reset controllers in microputer and microprocessor systems. During power-up the device tests the supply voltage and keeps the RESET and RESET outputs active (high and low, respectively) as long as the supply voltage has not reached its nominal voltage value. Taking RESIN low has the same effect. To ensure that the microputer system hasreset, the TL7700Athen initiates aninternal time delay that delays the return of the reset outputs to theirinactivestates. Since the timedelay for most microputersand microprocessors is in the order of several machine cycles, the device internal time delay is determined by an external time delay is determined by an external capacitor connected to the CT input (pin 3). td = 1.3 x 104 x CT Where : CT is in farads (F) and td in seconds (s). In addition, when the supply voltage drops below the nominal value, the outputs will be active until the supply voltage returns to the nominal value. An externalcapacitor(typically0.1 µF) must be connected to the REF output (pin 1) to reduce the influence of fast transients in the supply voltage. The TL7700AI series is characterized for operation from - 25o C to 85o C ; the TL7700AC series is characterized from 0o C to 70o C. April 2000 D SO 8 ORDERING NUMBERS Temperature Range 0 to 70 C -25 to 85o C o Minidip TL77XXACP TL77XXAIP S08 TL77XXACD TL77XXAID PIN CONNECTION (top view) 1/7 TL7700A Series BLOCK DIAGRAM - TL7702A R1 = 0Ω, R2 = open ; TL7705A R1 = 7.8 K Ω, R2 = 10kΩ ; TL7709A R1 = 19.7 K Ω, R2 = 10kΩ ; TL7712A R1 = 32.7kΩ, R2 = 10kΩ ; TL7715A R1 = 43.4...