MAX6821/MAX6825 Low-Voltage SOT23 P Supervisors with Manual Reset and Watchdog Timer General Description Features The MAX6821MAX6825 are low-voltage microproces- Monitors +1.8V, +2.5V, +3.0V, +3.3V, +5.0V Supplies sor (P) supervisory circuits that combine voltage mon- 140ms (min) Reset Timeout Delay itoring, watchdog timer, and manual reset input func- 1.6s Watchdog Timeout Period (MAX6821/MAX6822/ tions in a 5-pin SOT23 package. Microprocessor super- MAX6823/MAX6824) visory circuits significantly improve system reliability and Manual Reset Input (MAX6821/MAX6822/MAX6823/ accuracy compared to separate ICs or discrete compo- MAX6825) nents. These devices assert a reset signal whenever the Three Reset Output Options monitored voltage drops below its preset threshold, keep- ing it asserted for a minimum timeout period after V rises Push-Pull RESET CC Push-Pull RESET above the threshold. In addition, a watchdog timer monitors against code execution errors. A debounced manual reset Open-Drain RESET is also available. The MAX6821MAX6825 monitor voltag- Guaranteed Reset Valid to V = +1.0V CC es from +1.8V to +5.0V. These outputs are guaranteed to Immune to Short Negative V Transients CC be in the correct state for V down to +1.0V. CC No External Components Nine preprogrammed reset threshold voltages are Small 5-Pin SOT23 Packages available (see the Threshold Suffix Guide). The MAX6821, MAX6822, and MAX6823 all have a manual Ordering Information reset input and a watchdog timer. The MAX6821 has PART* TEMP RANGE PIN-PACKAGE push-pull RESET, the MAX6822 has open-drain RESET, MAX6821 UK-T -40C to +125C 5 SOT23-5 and the MAX6823 has push-pull RESET. The MAX6824 MAX6822 UK-T -40C to +125C 5 SOT23-5 has a watchdog timer and both push-pull RESET and push-pull RESET. The MAX6825 has a manual reset MAX6823 UK-T -40C to +125C 5 SOT23-5 input and both push-pull RESET and push-pull RESET. MAX6824 UK-T -40C to +125C 5 SOT23-5 The Selector Guide explains the functions offered in MAX6825 UK-T -40C to +125C 5 SOT23-5 this series of parts. *Insert the desired suffix letter (from the table below) into the blank to complete the part number Applications Devices are available in both leaded and lead(Pb)-free packag- ing.Specify lead-free by replacing -T with +T when ordering. Set-Top Boxes Intelligent Instruments Computers and Con- Critical P Monitoring Threshold Suffix Guide trollers Portable/Battery- RESET Embedded Controllers Powered Equipment SUFFIX THRESHOLD (V) L 4.63 M 4.38 Pin Configurations T 3.08 TOP VIEW S 2.93 R 2.63 RESET(RESET) 1 5 V CC Z 2.32 MAX6821 MAX6822 GND 2 Y 2.19 MAX6823 W 1.67 MR 3 4 WDI V 1.58 SOT23-5 Note: Bold indicates standard versions. Samples are typically (RESET) MAX6821 ONLY available for standard versions only. All parts require a 2.5k Pin Configurations continued at end of data sheet. minimum order increment. Contact factory for availability. Typical Operating Circuit appears at end of data sheet. Selector Guide appears at end of data sheet. 19-1868 Rev 3 7/14MAX6821/MAX6825 Low-Voltage SOT23 P Supervisors with Manual Reset and Watchdog Timer Absolute Maximum Ratings V to GND .........................................................-0.3V to +6.0V Operating Temperature Range ......................... -40C to +125C CC Open-Drain RESET ..............................................-0.3V to +6.0V Junction Temperature ......................................................+150C Push-Pull RESET, RESET, MR, WDI ....... -0.3V to (V + 0.3V) Storage Temperature Range ............................ -65C to +150C CC Input Current (V ) ............................................................20mA Lead Temperature (soldering, 10s) .................................+300C CC Output Current (RESET, RESET) ......................................20mA Continuous Power Dissipation (T = +70C) A 5-Pin SOT23 (derate 7.1mW/C above +70C) ..........571mW Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Electrical Characteristics (V = +4.5V to +5.5V for MAX682 L/M, V = +2.7V to +3.6V for MAX682 T/S/R, V = +2.1V to +2.75V for MAX682 Z/Y, V = CC CC CC CC +1.53V to +2.0V for MAX682 W/V, T = -40C to +125C, unless otherwise specified. Typical values are at T = +25C.) (Note 1) A A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS T = 0C to +85C 1.0 5.5 A Operating Voltage Range V V CC T = -40C to +125C 1.2 5.5 A T = -40C to +85C 10 20 A V = +5.5V, no load CC T = -40C to +125C 30 A T = -40C to +85C 7 16 V Supply Current A CC I V = +3.6V, no load A CC CC (MR and WDI Unconnected) T = -40C to +125C 25 A T = -40C to +85C 5 12 A V = +3.6V, no load CC (MAX6825 only) T = -40C to +125C 20 A TA = -40C to +85C 4.50 4.63 4.75 MAX682 L T = -40C to +125C 4.47 4.63 4.78 A T = -40C to +85C 4.25 4.38 4.50 A MAX682 M T = -40C to +125C 4.22 4.38 4.53 A T = -40C to +85C 3.00 3.08 3.15 A MAX682 T T = -40C to +125C 2.97 3.08 3.17 A T = -40C to +85C 2.85 2.93 3.00 A MAX682 S T = -40C to +125C 2.83 2.93 3.02 A V CC Reset Threshold T = -40C to +85C 2.55 2.63 2.70 VTH A V V ( CC Falling) MAX682 R T = -40C to +125C 2.53 2.63 2.72 A T = -40C to +85C 2.25 2.32 2.38 A MAX682 Z T = -40C to +125C 2.24 2.32 2.40 A T = -40C to +85C 2.12 2.19 2.25 A MAX682 Y T = -40C to +125C 2.11 2.19 2.27 A T = -40C to +85C 1.62 1.67 1.71 A MAX682 W T = -40C to +125C 1.61 1.67 1.72 A MAX682 V T = -40C to +85C 1.52 1.58 1.62 A Reset Threshold Temperature 60 ppm/C Coefficient Reset Threshold Hysteresis 2 V mV TH V to Reset Output Delay t V = V to (V - 100mV) 20 s CC RD CC TH TH Maxim Integrated 2 www.maximintegrated.com