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MAX6721A：Dual/Triple, Ultra-Low-Voltage, SOT23 µP Supervisory Circuits

Dual/Triple-Voltage, µP Supervisors with Watchdog, Manual Reset Input, and/or Power-Fail Comparator

The MAX6715A–MAX6729A/MAX6797A are ultra-low-voltage microprocessor (µP) supervisory circuits designed to monitor two or three system power-supply voltages. These devices assert a system reset if any monitored supply falls below its factory-trimmed or adjustable threshold and maintain reset for a minimum timeout period after all supplies rise above their thresholds. The integrated dual/triple supervisory circuits significantly improve system reliability and reduce size compared to separate ICs or discrete components. These devices monitor primary supply voltages (VCC1) from 1.8V to 5.0V and secondary supply voltages (VCC2) from 0.9V to 3.3V with factory-trimmed reset threshold voltage options (see the Reset Voltage Threshold Suffix Guide in the full data sheet). An externally adjustable RSTIN input option allows customers to monitor a third supply voltage down to 0.62V. These devices are guaranteed to be in the correct reset output logic state when either VCC1 or VCC2 remains greater than 0.8V. A variety of push-pull or open-drain reset outputs along with watchdog input, manual-reset input, and power-fail input/output features are available (see the Selector Guide in the full data sheet). Select reset timeout periods from 1.1ms to 1120ms (min) (see the Reset Timeout Period Suffix Guide in the full data sheet). The MAX6715A–MAX6729A/MAX6797A are available in small 5-, 6-, and 8-pin SOT23 packages and operate over the -40°C to +125°C temperature range.

Key Features VCC1 (Primary Supply) Reset Threshold Voltages from 1.58V to 4.63V VCC2 (Secondary Supply) Reset Threshold Voltages from 0.79V to 3.08V Externally Adjustable RSTIN Threshold for Auxiliary/Triple-Voltage Monitoring (0.62V Internal Reference) Watchdog Timer Option 35s (min) Long Startup Period 1.12s (min) Normal Timeout Period Manual-Reset Input Option Power-Fail Input/Power-Fail Output Option (Push-Pull and Open-Drain Active-Low) Guaranteed Reset Valid Down to VCC1 or VCC2 = 0.8V Reset Output Logic Options Immune to Short VCC Transients Low Supply Current 14µA (typ) at 3.6V Watchdog Disable Feature Small 5-, 6-, and 8-Pin SOT23 Packages

MAX6715A, MAX6716A, MAX6717A, MAX6718A, MAX6719A, MAX6720A, MAX6721A, MAX6722A, MAX6723A, MAX6724A, MAX6725A, MAX6726A, MAX6727A, MAX6728A, MAX6729A: Typical Operating Circuit Applications/Uses Computers/Servers Industrial Equipment Multivoltage Systems Portable Battery-Powered Equipment Printers/Fax Machines Set-Top Boxes Telecom/Networking Equipment

DataSheet

Parametrics

Quality and Environmental Data

• MAX6721A.pdf

Ordering Information