Product Description
Low-Quiescent-Current, Programmable-Delay Supervisory Circuit
DESCRIPTION
The TPS3808 family of microprocessor supervisory circuits monitors system voltages from 0.4 V to 5 V, 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 useradjustable delay time after the SENSE voltage and manual reset ( MR) return above the respective thresholds. The TPS3808 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 TPS3808 device has a very low typical quiescent current of 2.4 µA, so it is wellsuited 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).
Features:
• Power-On Reset Generator with Adjustable Delay Time: 1.25 ms to 10 s
• Very Low Quiescent Current: 2.4 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
