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FUNCTIONAL DESCRIPTION The family of microprocessor supervisory circuits monitors system voltages from 0.4 V to 5V, asserting an open-drain 𝐑𝐄𝐒𝐄𝐓 signal when the SENSE voltage drops below a preset threshold or when the manual reset (𝐌𝐑) pin drops to a logic low. The 𝐑𝐄𝐒𝐄𝐓 output remains low for the user-adjustable delay time after the SENSE voltage and manual reset (𝐌𝐑) return above the respective thresholds. The device uses a precision reference to achieve 0.5% threshold accuracy for VIT ≤ 3.3 V. The reset delay time can be set to 20 ms by disconnecting the CT pin, 300 ms by connecting the CT pin to VDD using a resistor, or can be user adjusted between 1.25 ms and 10 s by connecting the CT pin to an external capacitor. The device has a very low typical quiescent current of 1.7 μA, so it is well-suited to battery-powered applications. It is available in the SOT-23 and 2- mm × 2-mm WSON packages, and is fully specified over a temperature range of – 40°C to 125°C (TJ). MAIN FEATURES • Power-On Reset Generator with Adjustable Delay Time: 1.25 ms to 10 s • Very Low Quiescent Current: 1.7 μA Typical • High Threshold Accuracy: 0.5% Typ • Fixed Threshold Voltages for Standard Voltage Rails from 0.9 V to 5 V and Adjustable Voltage Down to 0.4 V Are Available • Manual Reset (𝐌𝐑) Input • Open-Drain 𝐑𝐄𝐒𝐄𝐓 Output • Temperature Range: –40°C to 125°C • Small SOT-23 and 2-mm × 2-mm WSON Packages APPLICATIONS • DSP or Microcontroller Applications • Notebook and Desktop Computers • PDAs and Hand-Held Products • Portable and Battery-Powered Products • FPGA and ASIC Applications |
