19-2690; Rev 2; 12/07 Power-Supply Monitor with Reset The MAX700/MAX701/MAX702 are supervisory circuits used to monitor the power supplies in microprocessor (µP) and digital systems. The RESET/RESET outputs of the MAX700/MAX701/MAX702 are guaranteed to be in the correct state for VCC voltages down to +1V (Figure 4). They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +5V-powered circuits. The MAX702 is the simplest part in the family. When VCC falls to 4.65V, RESET goes low. The MAX702 also provides a debounced manual reset input. The MAX701 performs the same functions but has both RESET and RESET outputs. Their primary function is to provide a system reset. Accordingly, an active reset signal is supplied for low supply voltages and for at least 200ms after the supply voltage reaches its operating value. In addition to the features of the MAX701 and MAX702, the MAX700 provides preset or adjustable voltage detection so thresholds other than 4.65V can be selected, and adjustable hysteresis. All parts are supplied in 8-pin PDIP and Narrow SO packages in commercial and extended temperature ranges. Applications Features ♦ Min 200ms RESET Pulse on Power-Up, PowerDown, and During Low-Voltage Conditions ♦ Reset Threshold Factory Trimmed for +5V Systems ♦ No External Components or Adjustments with +5V-Powered Circuits ♦ Debounced Manual Reset Input ♦ Preset or Adjustable Voltage Detection (MAX700) ♦ Adjustable Hysteresis (MAX700) ♦ 8-Pin PDIP and Narrow SO Packages Ordering Information PART* TEMP RANGE PIN-PACKAGE MAX700C/D 0°C to +70°C Dice MAX700CPA 0°C to +70°C 8 PDIP MAX700CSA 0°C to +70°C 8 Narrow SO MAX700EPA -40°C to +85°C 8 PDIP MAX700ESA -40°C to +85°C 8 Narrow SO MAX701C/D 0°C to +70°C Dice MAX701CPA 0°C to +70°C 8 PDIP 8 Narrow SO MAX701CSA 0°C to +70°C Computers MAX701EPA -40°C to +85°C 8 PDIP Controllers MAX701ESA -40°C to +85°C 8 Narrow SO Intelligent Instruments MAX702C/D 0°C to +70°C Automotive Systems MAX702CPA 0°C to +70°C 8 PDIP MAX702CSA 0°C to +70°C 8 Narrow SO MAX702EPA -40°C to +85°C Critical µP Power Monitoring Dice 8 PDIP MAX702ESA -40°C to +85°C 8 Narrow SO *Devices in PDIP and SO packages are available in both leaded and lead-free packaging. Specify lead free by adding the + symbol at the end of the part number when ordering. Pin Configurations TOP VIEW MR 1 SENSE 2 8 VCC MR 1 7 CTL N.C. 2 MAX700 8 VCC MR 1 7 N.C. VCC 2 MAX701 8 N.C. 7 RESET MAX702 3 6 RESET N.C. 3 6 RESET GND 3 6 N.C. GND 4 5 RESET GND 4 5 RESET N.C. 4 5 N.C. HYST DIP/SO DIP/SO DIP/SO ________________________________________________________________ Maxim Integrated Products 1 For pricing delivery, and ordering information please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX700/MAX701/MAX702 General Description MAX700/MAX701/MAX702 Power-Supply Monitor with Reset ABSOLUTE MAXIMUM RATINGS VCC ......................................................................-0.3V to +15.5V Voltage (with respect to GND) at RESET, RESET, HYST, CTL, SENSE ............................................-0.3V to VCC Operating Temperature Range C Suffix .............................................................0°C to +70°C E Suffix...........................................................-40°C to +85°C Rate of Rise, VCC ............................................................100V/µs Power Dissipation, Any Package .....................................380mW Storage Temperature Range .............................-55°C to +150°C Lead Temperature (soldering, 10s)..................................+300°C 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 (VCC = +5V, CTL = GND on MAX700, TA = +25°C, unless otherwise noted.) PARAMETER CONDITIONS VCC Monitor Voltage Range (MAX700 Only) TA = TMIN to TMAX, CTL = VCC Min VCC for Valid Reset Output, Declining Supply TA = TMIN to TMAX, RESET ≤ 0.4V when sinking 1mA MIN 3 TA = TMIN to TMAX Internal Hysteresis HYST not connected VCC Pulse Duration Guaranteeing 15 V 100 200 Power-up 4.50 4.65 4.75 Power-down 4.50 4.62 4.75 200 350 V 30 MAX700/MAX701 only, CLOAD = 100pF 5V to 4V VCC pulse UNITS 1 Reset Output Pulse Width RESET Fall Time MAX 1.5 Supply Current Reset Threshold TYP Reset 10 100 0.7 MR Pullup Current -5 ms ns 1 10 MR Input Threshold V mV 500 200 No reset µA µs V -30 µA MAX700 RESET Output Low RESET Output High RESET Output Low ISINK = 3.2mA, VCC = 5V 0.4 ISINK = 1.6mA, VCC = 3V 0.4 ISOURCE = 3.2mA, VCC = 4.25V VCC 0.4 ISOURCE = 1.6mA, VCC = 3V VCC 0.4 ISOURCE = 0.5mA, VCC = 1.5V VCC 0.4 0.4 ISINK = 1.6mA, VCC = 3V 0.4 ISINK = 0.4mA, VCC = 1.5V 0.4 VCC 0.4 ISOURCE = 1.6mA, VCC = 3V VCC 0.4 RESET Output High 2 V ISINK = 16mA, VCC = 4.25V ISOURCE = 3.2mA, VCC = 5V V V V _______________________________________________________________________________________ Power-Supply Monitor with Reset MAX700/MAX701/MAX702 ELECTRICAL CHARACTERISTICS (continued) (VCC = +5V, CTL = GND on MAX700, TA = +25°C, unless otherwise noted.) PARAMETER CONDITIONS MIN TYP MAX UNITS 0.4 V MAX701 RESET Output Low ISINK = 16mA, VCC = 5V RESET Output High RESET Output Low RESET Output High ISOURCE = 3.2mA, VCC = 4.25V VCC 0.4 ISOURCE = 1.6mA, VCC = 3V VCC 0.4 ISOURCE = 0.5mA, VCC = 1.5V VCC 0.4 V ISINK = 3.2mA, VCC = 4.25V 0.4 ISINK = 1.6mA, VCC = 3V 0.4 ISINK = 0.4mA, VCC = 1.5V 0.4 ISOURCE = 3.2mA, VCC = 5V VCC 0.4 V V MAX702 RESET Output Low RESET Output High ISINK = 3.2mA, VCC = 4.25V 0.4 ISINK = 1.6mA, VCC = 3V 0.4 ISINK = 0.4mA, VCC = 1.5V 0.4 ISOURCE = 3.2mA, VCC = 5V VCC 0.4 V V MAX700 ONLY (CTL = VCC, unless otherwise noted) SENSE Input Threshold TA = TMIN to TMAX 1.25 1.29 1.35 V SENSE Input Current 0.1 nA HYST Input On-Resistance 0.5 kΩ CTL Input Threshold 2 V CTL Pulldown Current 30 100 µA _______________________________________________________________________________________ 3 Power-Supply Monitor with Reset MAX700/MAX701/MAX702 Pin Description PIN 4 NAME MAX700 MAX701 MAX702 1 1 1 MR 2 — — SENSE FUNCTION Input for Manual Pushbutton Reset. Has internal 5µA pullup. Low input activates the RESET/RESET outputs. The voltage-sense input when CTL = VCC. Its threshold is 1.29V. SENSE always remains connected to the internal comparator. So, when VCC is being monitored internally (CTL = GND), SENSE should be left open circuit. 3 — — HYST Normally NOT used when voltage is monitored through VCC (CTL = GND). When monitoring through SENSE (CTL = VCC), HYST allows hysteresis to be added, reducing noise and spurious reset activity (Figure 3). HYST turns on 5µs before the RESET/RESET outputs are activated, and its on-resistance to GND is typically 1kΩ. 4 4 3 GND Ground 5 6 7 RESET Goes low when VCC falls below 4.65V, or when CTL = VCC on the MAX700 goes low when SENSE falls below 1.29V. 6 5 — RESET Inverted Version of RESET 7 — — CTL When CTL = GND, VCC is monitored by the reset circuit. When CTL = VCC, VCC is ignored and SENSE is monitored, allowing the threshold to be set with external resistors. 8 8 2 VCC Chip Power and +5V Sensing Input (When CTL = GND on MAX700) — 2, 3, 7 4, 5, 6, 8 N.C. No Connection _______________________________________________________________________________________ Power-Supply Monitor with Reset 1MΩ 1 8 7 COMPARATOR SENSE 2 VCC MANUAL RESET BUTTON CTL 1 150kΩ N.C. MAX700 RC 6 R OSC HYST 4 RESET MAX700 MR SENSE VCC CTL RESET HYST RESET GND 8 +5V 7 6 N.C. 5 TO µP 3 5 GND 2 3 1.29V REF R MAX700/MAX701/MAX702 MR RESET 4 Figure 2. MAX700 Typical Connection Diagram Figure 1. MAX700 Block Diagram MANUAL RESET BUTTON 1 R1 2 VIN R2 MR MAX700 VCC SENSE CTL 8 VIN 3V TO 15V 7 2V/div RESET R3 3 4 HYST GND RESET RESET 6 N.C. 5 0V TO µP 2V/div VCC VL - 1 VL = LOWER VOLTAGE THRESHOLD 1.29 VTR1 R3 = V = UPPER VOLTAGE THRESHOLD VU - V L U ( R1 = R2 ) 0V 1s/div HYSTERESIS = VU - VL Figure 3. MAX700 Connected for External Senses and Hysteresis Figure 4 shows the RESET output of the MAX700/ MAX701/MAX702 in the correct state for VCC voltages down to 0V. Note the effect of the built-in hysteresis on the trigger lever of RESET. Figure 4. Typical MAX700/MAX701/MAX702 RESET Output vs. VCC Package Information For the latest package outline information, go to www.maxim-ic.com/packages. _______________________________________________________________________________________ 5 MAX700/MAX701/MAX702 Power-Supply Monitor with Reset Revision History REVISION NUMBER REVISION DATE 0 3/90 1 11/05 Added lead-free information to the Ordering Information table. 1 2 12/07 Updated Pin Description table. 4 DESCRIPTION Initial release PAGES CHANGED — Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 6 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2008 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.