19-1623; Rev 1; 12/05 4-Pin SC70 Microprocessor Reset Circuits with Manual Reset Input ____________________________Features The MAX6711/MAX6712/MAX6713 are microprocessor (µP) supervisory circuits used to monitor the power supplies in µP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +5.0V, +3.3V, +3.0V, or +2.5V-powered circuits. They also provide a debounced manual reset input. ♦ Precision Monitoring of 2.5V, 3.0V, 3.3V, and 5.0V Power-Supply Voltages ♦ Fully Specified Over Temperature ♦ Available in Three Output Configurations Push-Pull RESET Output (MAX6711) Push-Pull RESET Output (MAX6712) Open-Drain RESET Output (MAX6713) ♦ 140ms min Power-On Reset Pulse Width ♦ Manual Reset Input ♦ 12µA Supply Current ♦ Guaranteed Reset Valid to VCC = +1V ♦ Power-Supply Transient Immunity ♦ No External Components ♦ 4-Pin SC70 Package These circuits assert a reset signal whenever the VCC supply voltage declines below a preset threshold or whenever manual reset is asserted. Reset remains asserted for at least 140ms after VCC has risen above the reset threshold or when manual reset is deasserted. Reset thresholds suitable for operation with a variety of supply voltages are available. The MAX6713 has an open-drain output stage, while the MAX6711/MAX6712 have push-pull outputs. The MAX6713’s open-drain RESET output requires a pull-up resistor that can be connected to a voltage higher than VCC. The MAX6711/MAX6713 have an active-low reset output, while the MAX6712 has an active-high reset output. The reset comparator is designed to ignore fast transients on VCC, and the outputs are guaranteed to be in the correct logic state for VCC down to 1V. Low supply current makes the MAX6711/MAX6712/ MAX6713 ideal for use in portable equipment. These devices are available in a 4-pin SC70 package. Applications Computers Controllers Intelligent Instruments Critical µP and µC Power Monitoring Portable/Battery-Powered Equipment Automotive Ordering Information PART TEMP RANGE MAX6711_EXS-T MAX6711_EXS-T10 MAX6712_EXS-T MAX6712_EXS-T10 MAX6713_EXS-T MAX6713_EXS-T10 -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C PIN-PACKAGE 4 SC70-4 4 SC70-4 4 SC70-4 4 SC70-4 4 SC70-4 4 SC70-4 Note: These parts are offered in 2.5k or 10k reels and must be ordered in 2.5k or 10k increments. Order MAX6711_EXS-T for 2.5k reels and MAX6711_EXS-T10 for 10k reels. Insert the desired suffix letter from the Selector Guide into the blank to complete the part number. Devices are available in both leaded and lead-free packaging. Specify lead-free by replacing “-T” with “+T” when ordering. Selector Guide appears at end of data sheet. Typical Operating Circuit Pin Configuration TOP VIEW VCC VCC VCC GND 1 4 VCC 3 MR RPULL-UP* µP MAX6711 MAX6713 RESET PUSHBUTTON MR SWITCH GND *MAX6713 ONLY MAX6711 MAX6712 MAX6713 RESET INPUT GND RESET (RESET) 2 ( ) ARE FOR MAX6712. SC70-4 ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z General Description MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z 4-Pin SC70 Microprocessor Reset Circuits with Manual Reset Input ABSOLUTE MAXIMUM RATINGS Terminal Voltage (with respect to GND) VCC ........................................................................-0.3V to +6.0V RESET, RESET (push-pull) .........................-0.3V to (VCC + 0.3V) RESET (open drain)...............................................-0.3V to +6.0V MR ..............................................................-0.3V to (VCC + 0.3V) Input Current, VCC, MR .......................................................20mA Output Current, RESET, RESET ..........................................20mA Rate of Rise, VCC ............................................................100V/µs Continuous Power Dissipation (TA = +70°C) 4-Pin SC70 (derate 3.1mW/°C above +70°C) ..............245mW Operating Temperature Range .........................-40°C to +125°C Storage Temperature Range .............................-65°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 = full range, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = +5V for L/M versions, VCC = +3.3V for T/S versions, VCC = +3V for R version, VCC = +2.5V for Z version, and TA = +25°C.) (Note 1) PARAMETER SYMBOL VCC Range CONDITIONS ICC TA = -40°C to +125°C 1.2 5.5 TA = +85°C to +125°C MAX671_M MAX671_T VTH MAX671_S MAX671_R MAX671_Z VCC < 5.5V, MAX671_L/M 16 35 VCC < 3.6V, MAX671_R/S/T/Z 12 30 VCC < 5.5V, MAX671_L/M 60 VCC < 3.6V, MAX671_R/S/T/Z Reset Active Timeout Period 2 UNITS V µA 60 TA = +25°C 4.56 TA = -40°C to +85°C 4.50 TA = +85°C to +125°C 4.44 TA = +25°C 4.31 TA = -40°C to +85°C 4.25 TA = +85°C to +125°C 4.20 TA = +25°C 3.04 TA = -40°C to +85°C 3.00 TA = +85°C to +125°C 2.95 TA = +25°C 2.89 TA = -40°C to +85°C 2.85 TA = +85°C to +125°C 2.81 TA = +25°C 2.59 TA = -40°C to +85°C 2.55 TA = +85°C to +125°C 2.52 TA = +25°C 2.28 TA = -40°C to +85°C 2.25 TA = +85°C to +125°C 2.22 Reset Threshold Tempco VCC to Reset Delay (Note 2) MAX 5.5 MAX671_L Reset Threshold TYP 1.0 TA = -40°C to +85°C Supply Current MIN TA = 0°C to +70°C 4.63 4.70 4.75 4.82 4.38 4.45 4.50 4.56 3.08 3.11 3.15 3.21 2.93 2.96 3.00 3.05 2.63 2.66 2.70 2.74 2.32 2.35 2.38 2.42 30 VCC = VTH to (VTH - 100mV) ppm/°C 20 TA = -40°C to +85°C 140 TA = +85°C to +125°C 100 V 240 _______________________________________________________________________________________ µs 460 640 ms 4-Pin SC70 Microprocessor Reset Circuits with Manual Reset Input (VCC = full range, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = +5V for L/M versions, VCC = +3.3V for T/S versions, VCC = +3V for R version, VCC = +2.5V for Z version, and TA = +25°C.) (Note 1) PARAMETER RESET Output-Voltage Low (MAX6711/MAX6713) RESET Output-Voltage High (MAX6711) RESET Output-Voltage Low (MAX6712) RESET Output-Voltage High (MAX6712) SYMBOL VOL VOH VOL VOH RESET Open-Drain Output Leakage Current MIN TYP MAX 0.3 VCC = VTH min, ISINK = 3.2mA, MAX6711L/M, MAX6713L/M 0.4 VCC > 1.0V, ISINK = 50µA 0.3 VCC > VTH max, ISOURCE = 500µA, MAX6711R/S/T/Z 0.8 · VCC VCC > VTH max, ISOURCE = 800µA, MAX6711L/M 0.8 · VCC UNITS V V VCC = VTH max, ISINK = 1.2mA, MAX6712R/S/T/Z 0.3 VCC = VTH max, ISINK = 3.2mA, MAX6712L/M 0.4 V 1.8V < VCC < VTH min, ISOURCE = 150µA 0.8 · VCC V VCC > VTH, RESET deasserted VIL MR Input Threshold CONDITIONS VCC = VTH min, ISINK = 1.2mA, MAX6711R/S/T/Z, MAX6713R/S/T/Z 1 0.3 · VCC 0.7 · VCC VIH MR Pull-Up Resistance 10 MR Minimum Pulse Width 1 20 µA V kΩ µs MR Glitch Immunity 100 ns MR to Reset Delay 200 ns Note 1: Production testing done at TA = +25°C; limits over temperature guaranteed by design only. Note 2: RESET output for MAX6711/MAX6713; RESET output for MAX6712. _______________________________________________________________________________________ 3 MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (VCC = full range, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = +5V for L/M versions, VCC = +3.3V for T/S versions, VCC = +3V for R version, VCC = +2.5V for Z version, and TA = +25°C.) MAX671 _Z, VCC = 2.5V MAX671 _R/S/T, VCC = 3.3V 5 MAX671 _L/M/R/S/T/Z, VCC = 1V 0 20 40 60 80 40 VOD = 100mV 100 120 0 20 40 60 80 VOD = 20mV 90 60 VOD = 100mV 30 0 -40 -20 100 120 VOD = 200mV 0 TEMPERATURE (°C) POWER-UP RESET TIMEOUT vs. TEMPERATURE MAX671_ R/S/T/Z 250 RESET THRESHOLD (V) 275 20 40 60 80 TEMPERATURE (°C) RESET THRESHOLD vs. TEMPERATURE 1.001 MAX6711/12/13-TOC4 300 POWER-UP RESET TIMEOUT (ms) 120 VOD = 200mV TEMPERATURE (°C) VTH = 4.63V 1.000 0.999 225 MAX671_ L/M 200 0.998 -40 -20 0 20 40 60 TEMPERATURE (°C) 4 150 MAX6711/12/13-TOC5 -40 -20 VOD = 20mV 0 -40 -20 0 VOD = 10mV 60 20 80 100 120 -40 -20 MAX6711/12/13-TOC3 VOD = 10mV POWER-DOWN RESET DELAY (µs) 10 180 MAX6711/12/13-TOC2 MAX671_L/M, VCC = 5V 80 POWER-DOWN RESET DELAY (µs) MAX6711/12/13 toc01 15 MAX671_L/M POWER-DOWN RESET DELAY vs. TEMPERATURE MAX671_R/S/T/Z POWER-DOWN RESET DELAY vs. TEMPERATURE SUPPLY CURRENT vs. TEMPERATURE (NO LOAD) SUPPLY CURRENT (µA) MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z 4-Pin SC70 Microprocessor Reset Circuits with Manual Reset Input 0 20 40 60 80 100 120 TEMPERATURE (°C) _______________________________________________________________________________________ 100 120 4-Pin SC70 Microprocessor Reset Circuits with Manual Reset Input PIN NAME 1 GND FUNCTION VCC Ground RESET (MAX6711/ MAX6713) RESET output remains low while VCC is below the reset threshold, and for at least 140ms after VCC rises above the reset threshold. RESET (MAX6712) RESET output remains high while VCC is below the reset threshold, and for at least 140ms after VCC rises above the reset threshold. 3 MR Manual Reset Input. RESET (RESET) remains asserted as long as MR is low, and for at least 140ms after MR is deasserted. This active-low input has an internal 20kΩ (typ) pull-up resistor. It can be driven from a TTL- or CMOSlogic line, or shorted to ground with a switch. Leave open or connect to VCC if unused. 4 VCC Supply Voltage (+5.0V, +3.3V, +3.0V, or +2.5V) 2 MAXIMUM TRANSIENT DURATION (µs) 400 TA = +25°C 320 240 160 MAX671_L/M 80 0 10 RESET MR GND R1 100k Figure 2. RESET Valid to VCC = Ground Circuit least 140ms after VCC has risen above the reset threshold. The MAX6713 uses an open-drain output, and the MAX6711/MAX6712 have a push-pull output stage. Connect a pull-up resistor on the MAX6713’s RESET output to any supply between 0 and 6V. Manual Reset Input Many µP-based systems require manual reset capability, allowing the operator, a test technician, or external logic circuitry to initiate a reset. Reset remains asserted while MR is low, and for at least 140ms after MR returns high. This input has an internal 20kΩ pullup resistor, so it can be left open if it is not used. MR can be driven with TTL- or CMOS-logic levels, or with open-drain/collector outputs. To create a manual reset function, connect a normally open momentary switch from MR to ground; external debounce circuitry is not required. If MR is driven from long cables or if the device is used in a noisy environment, connecting a 0.1µF capacitor from MR to ground provides additional noise immunity. Applications Information MAX671_R/S/T/Z 1 MAX6711 100 1000 RESET COMPARATOR OVERDRIVE, VTH - VCC (mV) Figure 1. Maximum Transient Duration Without Causing a Reset Pulse vs. Reset Comparator Overdrive Detailed Description Reset Output A microprocessor’s (µP’s) reset input starts the µP in a known state. The MAX6711/MAX6712/MAX6713 assert reset to prevent code-execution errors during powerup, power-down, or brownout conditions. They assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at Negative-Going VCC Transients In addition to issuing a reset to the µP during power-up, power-down, and brownout conditions, the MAX6711/ MAX6712/MAX6713 are relatively immune to short-duration negative-going VCC transients (glitches). Figure 1 shows typical transient duration vs. reset comparator overdrive, for which the MAX6711/MAX6712/ MAX6713 do not generate a reset pulse. The graph was generated using a negative-going pulse applied to VCC, starting 0.5V above the actual reset threshold and ending below it by the magnitude indicated (reset comparator overdrive). The graph indicates the maximum pulse width a negative-going VCC transient can have without causing a reset pulse. As the magnitude of the transient increases (goes farther below the reset threshold), the _______________________________________________________________________________________ 5 MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z _____________________Pin Description MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z 4-Pin SC70 Microprocessor Reset Circuits with Manual Reset Input +5.0V +3.3V VCC VCC VCC VCC VCC RPULLUP µP MAX6713 RESET MOTOROLA RESET 68HCXX INPUT 5V SYSTEM MAX6713 RESET RESET INPUT MR GND GND Figure 3. Interfacing to µPs with Bidirectional Reset I/O maximum allowable pulse width decreases. Typically, for the MAX671_L and MAX671_M, a VCC transient that goes 100mV below the reset threshold and lasts 20µs or less will not cause a reset pulse. A 0.1µF bypass capacitor mounted as close as possible to the VCC pin provides additional transient immunity. Ensuring a Valid Reset Output Down to VCC = 0 When VCC falls below 1V, the MAX6711 RESET output no longer sinks current—it becomes an open circuit. Therefore, high-impedance CMOS-logic inputs connected to RESET can drift to undetermined voltages. This presents no problem in most applications since most µP and other circuitry is inoperative with VCC below 1V. However, in applications where RESET must be valid down to 0, adding a pull-down resistor to RESET causes any stray leakage currents to flow to ground, holding RESET low (Figure 2). R1’s value is not critical; 100kΩ is large enough not to load RESET and small enough to pull RESET to ground. A 100kΩ pull-up resistor to VCC is also recommended for the MAX6712 if RESET is required to remain valid for VCC < 1V. Interfacing to µPs with Bidirectional Reset Pins Since the RESET output on the MAX6713 is open-drain, this device interfaces easily with µPs that have bidirectional reset pins, such as the Motorola 68HC11. Connecting the µP supervisor’s RESET output directly to the µP’s RESET pin with a single pull-up resistor allows either device to assert reset (Figure 3). 6 GND GND Figure 4. MAX6713 Open-Drain RESET Output Allows Use with Multiple Supplies MAX6713 Open-Drain RESET Output Allows Use with Multiple Supplies Generally, the pull-up connected to the MAX6713 will connect to the supply voltage that is being monitored at the IC’s VCC pin. However, some systems may use the open-drain output to level-shift from the monitored supply to reset circuitry powered by some other supply (Figure 4). Note that as the MAX6713’s VCC decreases below 1V, so does the IC’s ability to sink current at RESET. Also, with any pullup, RESET will be pulled high as VCC decays toward 0. The voltage where this occurs depends on the pull-up resistor value and the voltage to which it is connected. Benefits of Highly Accurate Reset Threshold Most µP supervisor ICs have reset threshold voltages between 5% and 10% below the value of nominal supply voltages. This ensures a reset will not occur within 5% of the nominal supply, but will occur when the supply is 10% below nominal. When using ICs rated at only the nominal supply ±5%, a zone of uncertainty where the supply is between 5% and 10% low, and where the reset may or may not be asserted is left. The MAX671_L/T/Z use highly accurate circuitry to ensure that reset is asserted close to the 5% limit, and long before the supply has declined to 10% below nominal. ___________________Chip Information TRANSISTOR COUNT: 380 _______________________________________________________________________________________ 4-Pin SC70 Microprocessor Reset Circuits with Manual Reset Input PART/SUFFIX RESET THRESHOLD (V) OUTPUT TYPE TOP MARK MAX6711L 4.63 Push-Pull RESET AAB MAX6711M 4.38 Push-Pull RESET AAC MAX6711T 3.08 Push-Pull RESET AAD AAE MAX6711S 2.93 Push-Pull RESET MAX6711R 2.63 Push-Pull RESET AAF MAX6711Z 2.32 Push-Pull RESET AAG AAH MAX6712L 4.63 Push-Pull RESET MAX6712M 4.38 Push-Pull RESET AAI MAX6712T 3.08 Push-Pull RESET AAJ AAK MAX6712S 2.93 Push-Pull RESET MAX6712R 2.63 Push-Pull RESET AAL MAX6712Z 2.32 Push-Pull RESET AAM MAX6713L 4.63 Open-Drain RESET AAN MAX6713M 4.38 Open-Drain RESET AAO MAX6713T 3.08 Open-Drain RESET AAP MAX6713S 2.93 Open-Drain RESET AAQ MAX6713R 2.63 Open-Drain RESET AAR MAX6713Z 2.32 Open-Drain RESET AAS _______________________________________________________________________________________ 7 MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z Selector Guide Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) SC70, 4L.EPS MAX6711L/M/R/S/T/Z, MAX6712L/M/R/S/T/Z, MAX6713L/M/R/S/T/Z 4-Pin SC70 Microprocessor Reset Circuits with Manual Reset Input PACKAGE OUTLINE, 4L SC70 21-0098 C 1 1 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. 8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.