MAX6730AMAX6735A 19-0605 Rev 0 8/06 Single-/Dual-/Triple-Voltage P Supervisory Circuits with Independent Watchdog Output General Description Features The MAX6730AMAX6735A single-/dual-/triple-voltage V 1 (Primary Supply) Reset Threshold Voltages CC microprocessor (P) supervisors feature a watchdog from +1.575V to +4.63V timer and manual reset capability. The MAX6730A V 2 (Secondary Supply) Reset Threshold CC MAX6735A offer factory-set reset thresholds for moni- Voltages from +0.79V to +3.08V toring voltages from +0.9V to +5V and an adjustable reset input for monitoring voltages down to +0.63V. The Adjustable RSTIN Threshold for Monitoring Voltages combination of these features significantly improves Down to +0.63V (MAX6734A/MAX6735A Only) system reliability and accuracy when compared to sep- Six Reset Timeout Options arate ICs or discrete components. Watchdog Timer with Independent Watchdog Output The active-low reset output asserts and remains asserted for the reset timeout period after all the monitored volt- 35s (min) Initial Watchdog Startup Period ages exceed their respective thresholds. Multiple factory- 1.12s (min) Normal Watchdog Timeout Period set reset threshold combinations reduce the number of Manual Reset Input (MAX6730A/MAX6731A/ external components required. The MAX6730A/ MAX6734A/MAX6735A) MAX6731A monitor a single fixed voltage, the MAX6732A/ MAX6733A monitor two fixed voltages, and the Guaranteed Reset Valid down to MAX6734A/MAX6735A monitor two fixed voltages and one V 1 or V 2 = +0.8V CC CC adjustable voltage. All devices are offered with six mini- Push-Pull RESET or Open-Drain RESET Output mum reset timeout periods ranging from 1.1ms to 1120ms. Immune to Short V Transients CC The MAX6730AMAX6735A feature a watchdog timer with an independent watchdog output. The watchdog Low Supply Current: 14A (typ) at +3.6V timer prevents system lockup during code execution Small 6-Pin and 8-Pin SOT23 Packages errors. A watchdog startup delay of 54s after reset asserts allows system initialization during power-up. The watchdog operates in normal mode with a 1.68s Ordering Information delay after initialization. The MAX6730A/MAX6732A/ MAX6734A provide an active-low, open-drain watch- PART* PIN-PACKAGE PKG CODE dog output. The MAX6731A/MAX6733A/MAX6735A MAX6730A UT D -T 6 SOT23-6 U6-1 provide an active-low, push-pull watchdog output. MAX6731AUT D -T 6 SOT23-6 U6-1 Other features include a manual reset input (MAX6730A/ MAX6732A UT D -T 6 SOT23-6 U6-1 MAX6731A/MAX6734A/MAX6735A) and push-pull reset MAX6733A UT D -T 6 SOT23-6 U6-1 output (MAX6731A/MAX6733A/MAX6735A) or open- drain reset output (MAX6730A/MAX6732A/MAX6734A). MAX6734A KA D -T 8 SOT23-8 K8S-3 The MAX6730AMAX6733A are offered in a tiny 6-pin MAX6735AKA D -T 8 SOT23-8 K8S-3 SOT23 package. The MAX6734A/MAX6735A are offered All devices specified over the -40C to +125C operating tem- in an 8-pin, space-saving SOT23 package. All devices perature range. are fully specified over the extended -40C to +125C *Note: Insert the threshold level suffixes for V 1 and V 2 temperature range. CC CC (Table 1) after UT or KA. For the MAX6730A/MAX6731A, Applications insert only the V 1 threshold suffix after the UT. Insert the CC reset timeout delay (Table 2) after D to complete the part num- Multivoltage Systems ber. For example, the MAX6732AUTLTD3-T provides a V 1 CC Telecom/Networking Equipment threshold of +4.625V, a V 2 threshold of +3.075V, and a CC Computers/Servers 210ms reset timeout period. Sample stock is generally held on standard versions only (see the Standard Versions table). Portable/Battery-Operated Equipment Standard versions have an order increment requirement of 2500 Industrial Equipment pieces. Nonstandard versions have an order increment require- Printer/Fax ment of 10,000 pieces. Contact factory for availability. Devices are available in both leaded and lead-free packaging. Set-Top Boxes Specify lead-free by replacing T with +T when ordering. Typical Operating Circuit and Pin Configurations appear at end of data sheet. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.Single-/Dual-/Triple-Voltage P Supervisory Circuits with Independent Watchdog Output ABSOLUTE MAXIMUM RATINGS V 1, V 2, RSTIN, MR, WDI to GND.....................-0.3V to +6V Operating Temperature Range .........................-40C to +125C CC CC Storage Temperature Range .............................-65C to +150C RST, WDO to GND (open drain)...............................-0.3V to +6V RST, WDO to GND (push-pull).................-0.3V to (V 1 + 0.3V) Junction Temperature......................................................+150C CC Lead Temperature (soldering, 10s) .................................+300C Input Current/Output Current (all pins) ...............................20mA Continuous Power Dissipation (T = +70C) A 6-Pin SOT23-6 (derate 8.7mW/C above +70C) ........696mW 8-Pin SOT23-8 (derate 8.9mW/C above +70C) ........714mW 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 1 = V 2 = +0.8V to +5.5V, T = -40C to +125C, unless otherwise noted. Typical values are at T = +25C.) (Note 1) CC CC A A PARAMETER SYMB O L CONDITIONS MIN TYP MAX UNITS V 1, CC Supply Voltage 0.8 5.5 V V 2 CC V 1 < +5.5V, all I/O connections CC 15 39 open, outputs not asserted I 1 CC V 1 < +3.6V, all I/O connections CC 10 28 open, outputs not asserted Supply Current A V 2 < +3.6V, all I/O connections CC 411 open, outputs not asserted I 2 CC V 2 < +2.75V, all I/O connections CC 39 open, outputs not asserted L (falling) 4.500 4.625 4.750 M (falling) 4.250 4.375 4.500 T (falling) 3.000 3.075 3.150 S (falling) 2.850 2.925 3.000 V 1 Reset Threshold V 1 R (falling) 2.550 2.625 2.700 V CC TH Z (falling) 2.250 2.313 2.375 Y (falling) 2.125 2.188 2.250 W (falling) 1.620 1.665 1.710 V (falling) 1.530 1.575 1.620 2 MAX6730AMAX6735A