MAX803/MAX809/MAX810 MAX803 MAX809/MAX810 MAX803/MAX809 MAX810 MAX803/MAX809/ - Datasheet Archive

 

3-Pin Microprocessor Reset Circuits The MAX803/MAX809/MAX810 are microprocessor (µP) supervisory circuits used to monitor

 

19-0344; Rev 5; 1/01 3-Pin Microprocessor Reset Circuits The MAX803/MAX809/MAX810 MAX803/MAX809/MAX810 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 +5V, +3.3V, +3.0V, or +2.5V powered circuits. These circuits perform a single function: they assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold. Reset thresholds suitable for operation with a variety of supply voltages are available. The MAX803 MAX803 has an open-drain output stage, while the MAX809/MAX810 MAX809/MAX810 have push-pull outputs. The MAX803 MAX803's open-drain RESET output requires a pull-up resistor that can be connected to a voltage higher than VCC. The MAX803/MAX809 MAX803/MAX809 have an active-low RESET output, while the MAX810 MAX810 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 MAX803/MAX809/ MAX803/MAX809/ MAX810 MAX810 ideal for use in portable equipment. The MAX803 MAX803 is available in a 3-pin SC70 package, and the MAX809/MAX810 MAX809/MAX810 are available in 3-pin SC70 or SOT23 packages. Applications Computers Controllers Intelligent Instruments Critical µP and µC Power Monitoring Portable/Battery-Powered Equipment Automotive _Features o Precision Monitoring of +2.5V, +3V, +3.3V, and +5V Power-Supply Voltages o Fully Specified Over Temperature o Available in Three Output Configurations Open-Drain RESET Output (MAX803 MAX803) Push-Pull RESET Output (MAX809 MAX809) Push-Pull RESET Output (MAX810 MAX810) o 140ms min Power-On Reset Pulse Width o 12µA Supply Current o Guaranteed Reset Valid to VCC = +1V o Power Supply Transient Immunity o No External Components o 3-Pin SC70 and SOT23 Packages Ordering Information PART TEMP. RANGE PIN-PACKAGE MAX803 MAX803_EXR-T MAX803 MAX803_EXR-T10 EXR-T10 MAX809 MAX809_EXR-T MAX809 MAX809_EXR-T10 EXR-T10 MAX809 MAX809_EUR-T MAX809 MAX809_EUR-T10 EUR-T10 MAX810 MAX810_EXR-T MAX810 MAX810_EXR-T10 EXR-T10 MAX810 MAX810_EUR-T MAX810 MAX810_EUR-T10 EUR-T10 -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +105°C -40°C to +105°C -40°C to +125°C -40°C to +125°C -40°C to +105°C -40°C to +105°C 3 SC70-3 SC70-3 3 SC70-3 SC70-3 3 SC70-3 SC70-3 3 SC70-3 SC70-3 3 SOT23-3 3 SOT23-3 3 SC70-3 SC70-3 3 SC70-3 SC70-3 3 SOT23-3 3 SOT23-3 Note: These parts are offered in 2.5k or 10k reels, and must be ordered in 2.5k or 10k increments. Order MAX803 MAX803_EXR-T for 2.5k reels and MAX803 MAX803_EXR-T10 EXR-T10 for 10k reels. Insert the desired suffix letter from the Selector Guide into the blank to complete the part number. All versions of these products may not be available at the time of announcement. Contact factory for availability. Pin Configuration Typical Operating Circuit TOP VIEW VCC GND 1 VCC VCC RPULL-UP* RESET MAX803 MAX803 MAX809 MAX809 MAX810 MAX810 µP MAX803 MAX803 MAX809 MAX809 RESET INPUT 3 VCC RESET (RESET) 2 GND GND SC70-3/SOT23-3 SC70-3/SOT23-3 *MAX803 MAX803 ONLY ( ) ARE FOR MAX810 MAX810. MAX803 MAX803 AVAILABLE IN SC70-3 SC70-3 ONLY. _ 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 MAX803L/M/R/S/T/Z MAX803L/M/R/S/T/Z, MAX809J/L/M/R/S/T/Z MAX809J/L/M/R/S/T/Z, MAX810L/M/R/S/T/Z MAX810L/M/R/S/T/Z General Description MAX803L/M/R/S/T/Z MAX803L/M/R/S/T/Z, MAX809J/L/M/R/S/T/Z MAX809J/L/M/R/S/T/Z, MAX810L/M/R/S/T/Z MAX810L/M/R/S/T/Z 3-Pin Microprocessor Reset Circuits ABSOLUTE MAXIMUM RATINGS Continuous Power Dissipation (TA = +70°C) 3-Pin SC70 (derate 2.17mW/°C above +70°C) .174mW 3-Pin SOT23 (derate 4mW/°C above +70°C).320mW Operating Temperature Range 3-Pin SC70 .-40°C to +125°C 3-Pin SOT23.-40°C to +105°C Storage Temperature Range .-65°C to +150°C Lead Temperature (soldering, 10s) .+300°C 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 Input Current, VCC .20mA Output Current, RESET, RESET .20mA Rate of Rise, VCC .100V/µs 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 +105°C (SOT23) or TA = -40°C to +125°C (SC70), unless otherwise noted. Typical values are at TA = +25°C, VCC = 5V for L/M/J versions, VCC = 3.3V for T/S versions, VCC = 3V for R version, and VCC = 2.5V for Z version.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX TA = 0°C to +70°C 1.2 5.5 TA = -40°C to +125°C (MAX8_ _ _EXR) 1.2 ICC VCC < 5.5V, MAX8_ _L/M 24 60 VCC < 3.6V, MAX8_ _R/S/T/Z 17 50 TA = +85°C to +105°C VCC < 3.6V, MAX8_ _R/S/T/Z TA = -40°C to +85°C Supply Current (SC70) ICC TA = +85°C to +125°C VCC < 5.5V, MAX8_ _L/M 100 100 VCC < 5.5V, MAX8_ _L/M 24 VCC < 3.6V, MAX8_ _R/S/T/Z 17 35 60 VCC < 3.6V, MAX8_ _R/S/T/Z 60 4.86 4.31 TA = -40°C to +85°C 4.25 4.50 4.16 4.56 TA = +25°C 3.93 TA = -40°C to +85°C 3.89 4.10 TA = -40°C to +125°C 3.80 4.20 TA = +25°C MAX8_ _T 4.75 4.40 TA = -40°C to +125°C VTH 4.50 TA = +25°C MAX809J MAX809J (SOT only) 4.56 TA = -40°C to +85°C TA = -40°C to +125°C MAX8_ _M 4.63 3.04 4.38 4.00 3.08 4.70 4.45 4.06 3.11 3.15 2.92 3.23 2.89 TA = -40°C to +85°C 2.85 TA = -40°C to +125°C 2.78 TA = +25°C 2.59 TA = -40°C to +85°C 2.55 2.70 TA = -40°C to +125°C 2 3.00 TA = +25°C MAX8_ _R TA = -40°C to +85°C TA = -40°C to +125°C MAX8_ _S µA 30 VCC < 5.5V, MAX8_ _L/M TA = +25°C MAX8_ _L Reset Threshold (SOT only) V 5.5 TA = -40°C to +85°C Supply Current (SOT23) UNITS 5.5 TA = -40°C to +105°C (MAX8_ _ _EUR) VCC Range 1.0 2.50 2.76 2.93 2.96 3.00 3.08 2.63 _ 2.66 V 3-Pin Microprocessor Reset Circuits (VCC = full range, TA = -40°C to +105°C (SOT23) or TA = -40°C to +125°C (SC70), unless otherwise noted. Typical values are at TA = +25°C, VCC = 5V for L/M/J versions, VCC = 3.3V for T/S versions, VCC = 3V for R version, and VCC = 2.5V for Z version.) (Note 1) PARAMETER SYMBOL CONDITIONS 4.75 4.44 4.82 4.31 TA = -40°C to +85°C 4.25 4.50 4.20 4.56 3.04 TA = -40°C to +85°C 3.00 3.15 TA = -40°C to +125°C 2.95 3.21 TA = +25°C MAX8_ _S 4.70 TA = +25°C VTH 4.63 4.50 TA = -40°C to +125°C Reset Threshold (SC70 only) 4.56 TA = -40°C to +85°C TA = +25°C MAX8_ _T MAX TA = -40°C to +125°C MAX8_ _M TYP TA = +25°C MAX8_ _L MIN 2.89 4.38 3.08 2.93 4.45 3.11 2.96 TA = -40°C to +85°C 2.85 2.81 3.05 TA = +25°C 2.59 2.63 2.66 TA = -40°C to +85°C 2.55 2.70 TA = -40°C to +125°C MAX8_ _Z (SC70 only) 2.52 2.74 TA = +25°C 2.28 2.32 2.35 TA = -40°C to +85°C 2.25 2.38 TA = -40°C to +125°C 2.22 2.42 Reset Threshold Tempco 30 VCC to Reset Delay (Note 2) VCC = VTH to (VTH - 100 mV) Reset Active Timeout Period (SOT23) TA = -40°C to +85°C 140 TA = +85°C to +105°C 100 Reset Active Timeout Period (SC70) TA = -40°C to +85°C 140 TA = +85°C to +125°C 100 ppm/°C 20 240 µs 560 840 240 460 840 RESET Output Voltage High (push-pull active low MAX809 MAX809) RESET Output Voltage Low (pushpull active high, MAX810 MAX810) VCC = VTH min, ISINK = 1.2mA, MAX803R/S/T/Z MAX803R/S/T/Z, MAX809R/S/T/Z MAX809R/S/T/Z VOL VCC = VTH min, ISINK = 3.2mA, MAX803L/M MAX803L/M, MAX809J/L/M MAX809J/L/M 0.4 VCC > VTH max, ISOURCE = 800µA, MAX803L/M MAX803L/M, MAX809J/L/M MAX809J/L/M V 0.8VCC VCC - 1.5 V VCC = VTH max, ISINK = 1.2mA, MAX810R/S/T/Z MAX810R/S/T/Z VOL ms 0.3 VCC > VTH max, ISOURCE = 500µA, MAX803R/S/T/Z MAX803R/S/T/Z, MAX809R/S/T/Z MAX809R/S/T/Z VOH ms 0.3 VCC > 1.0V, ISINK = 50µA RESET Output Voltage Low (pushpull active low and open-drain active low, MAX803 MAX803 and MAX809 MAX809) V 3.00 TA = -40°C to +125°C MAX8_ _R UNITS 0.3 VCC = VTH max, ISINK = 3.2mA, MAX810L/M MAX810L/M 0.4 V _ 3 MAX803L/M/R/S/T/Z MAX803L/M/R/S/T/Z, MAX809J/L/M/R/S/T/Z MAX809J/L/M/R/S/T/Z, MAX810L/M/R/S/T/Z MAX810L/M/R/S/T/Z ELECTRICAL CHARACTERISTICS (continued) ELECTRICAL CHARACTERISTICS (continued) (VCC = full range, TA = -40°C to +105°C (SOT23) or TA = -40°C to +125°C (SC70), unless otherwise noted. Typical values are at TA = +25°C, VCC = 5V for L/M/J versions, VCC = 3.3V for T/S versions, VCC = 3V for R version, and VCC = 2.5V for Z version.) (Note 1) PARAMETER SYMBOL RESET Output Voltage High (push-pull active high, MAX810 MAX810) CONDITIONS MIN 1.8V < VCC < VTH min, ISOURCE = 150µA VOH RESET Open-Drain Output Leakage Current (MAX803 MAX803) (Note 3) TYP MAX UNITS 0.8VCC V VCC > VTH, RESET deasserted 1 µA Note 1: Production testing done at TA = +25°C; limits over temperature guaranteed by design only. Note 2: RESET output for MAX803/MAX809 MAX803/MAX809; RESET output for MAX810 MAX810. Note 3: Guaranteed by design, not production tested. Typical Operating Characteristics (VCC = full range, TA = -40°C to +105°C, unless otherwise noted. Typical values are at TA = +25°C, VCC = +5V for L/M/J versions, VCC = +3.3V for T/S versions, VCC = +3V for R version, and VCC = +2.5V for Z version.) POWER-DOWN RESET DELAY vs. TEMPERATURE (MAX8_ _R/S/T/Z) MAX8_ _R/S/T, VCC = 3.3V 10 MAX8_ _Z, VCC = 2.5V 5 80 VOD = 10mV 60 VOD = 20mV 40 VOD = 100mV 20 140 60 40 VOD = 200mV 0 20 40 60 -20 -40 85 20 0 40 TEMPERATURE (°C) TEMPERATURE (°C) 40 VOD = 200mV 0 85 -40 -20 20 0 40 TEMPERATURE (°C) NORMALIZED RESET THRESHOLD vs. TEMPERATURE 1.003 MAX803-TOC5 MAX803-TOC5 245 1.002 NORMALIZED THRESHOLD POWER-UP RESET TIMEOUT (ms) 60 POWER-UP RESET TIMEOUT vs. TEMPERATURE 250 MAX8_ _J/L/M 240 MAX8_ _R/S/T/Z 235 230 1.001 1.000 0.999 0.998 0.997 225 -40 -20 0 20 40 TEMPERATURE (°C) 4 VOD = 100mV MAX803-TOC6 MAX803-TOC6 0 VOD = 20mV 80 20 0 -20 VOD = 10mV 100 MAX8_ _L/M/R/S/T/Z, VCC = 1V -40 VOD = VTH - VCC 120 60 85 -40 -20 MAX803-TOC4 MAX803-TOC4 VOD = VTH - VCC POWER-DOWN RESET DELAY (µs) MAX803 MAX803 toc01 MAX8_ _L/M, VCC = 5V 100 POWER-DOWN RESET DELAY (µs) 15 POWER-DOWN RESET DELAY vs. TEMPERATURE (MAX8_ _J/L/M) MAX803-TOC3 MAX803-TOC3 SUPPLY CURRENT vs. TEMPERATURE (SC70 PACKAGE, NO LOAD) SUPPLY CURRENT (µA) MAX803L/M/R/S/T/Z MAX803L/M/R/S/T/Z, MAX809J/L/M/R/S/T/Z MAX809J/L/M/R/S/T/Z, MAX810L/M/R/S/T/Z MAX810L/M/R/S/T/Z 3-Pin Microprocessor Reset Circuits 0 20 40 60 TEMPERATURE (°C) _ 85 60 85 3-Pin Microprocessor Reset Circuits PART/SUFFIX RESET THRESHOLD (V) OUTPUT TYPE 4.63 4.38 3.08 2.93 2.63 2.32 4.63 4.38 4.00 3.08 2.93 2.63 2.32 4.63 4.38 3.08 2.93 2.63 2.32 OPEN-DRAIN RESET OPEN-DRAIN RESET OPEN-DRAIN RESET OPEN-DRAIN RESET OPEN-DRAIN RESET OPEN-DRAIN RESET PUSH-PULL RESET PUSH-PULL RESET PUSH-PULL RESET PUSH-PULL RESET PUSH-PULL RESET PUSH-PULL RESET PUSH-PULL RESET PUSH-PULL RESET PUSH-PULL RESET PUSH-PULL RESET PUSH-PULL RESET PUSH-PULL RESET PUSH-PULL RESET MAX803L MAX803L MAX803M MAX803M MAX803T MAX803T MAX803S MAX803S MAX803R MAX803R MAX803Z MAX803Z MAX809L MAX809L MAX809M MAX809M MAX809J MAX809J MAX809T MAX809T MAX809S MAX809S MAX809R MAX809R MAX809Z MAX809Z MAX810L MAX810L MAX810M MAX810M MAX810T MAX810T MAX810S MAX810S MAX810R MAX810R MAX810Z MAX810Z Detailed Description A microprocessor's (µP's) reset input starts the µP in a known state. The MAX803/MAX809/MAX810 MAX803/MAX809/MAX810 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 least 140ms after VCC has risen above the reset threshold. The MAX803 MAX803 uses an open-drain output, and the MAX809/MAX810 MAX809/MAX810 have a push-pull output stage. Connect a pull-up resistor on the MAX803 MAX803's RESET output to any supply between 0 and 6V. Pin Description PIN NAME 1 GND FUNCTION Ground RESET (MAX803/ MAX803/ MAX809 MAX809) RESET Output remains low while VCC is below the reset threshold, and for at least 140ms after VCC rises above the reset threshold. RESET (MAX810 MAX810) RESET Output remains high while VCC is below the reset threshold, and for at least 140ms after VCC rises above the reset threshold. VCC Supply Voltage (+5V, +3.3V, +3.0V, or +2.5V) 2 3 TOP MARK SOT SC70 AAAA ABAA CWAA ACAA ADAA AFAA AGAA AHAA AJAA AKAA ALAA AAZ ABA ABB ABC ABD ABE AAN AAO AAP AAQ AAR AAS AAT AAU AAV AAX AAW AAY Applications Information Negative-Going VCC Transients In addition to issuing a reset to the µP during power-up, power-down, and brownout conditions, the MAX803/ MAX803/ MAX809/MAX810 MAX809/MAX810 are relatively immune to short-duration negative-going VCC transients (glitches). Figure 1 shows typical transient duration vs. reset comparator overdrive, for which the MAX803/MAX809/ MAX803/MAX809/ MAX810 MAX810 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 maximum allowable pulse width decreases. Typically, for the MAX8_L and MAX8_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 MAX809 MAX809 RESET output no longer sinks current-it becomes an open circuit. _ 5 MAX803L/M/R/S/T/Z MAX803L/M/R/S/T/Z, MAX809J/L/M/R/S/T/Z MAX809J/L/M/R/S/T/Z, MAX810L/M/R/S/T/Z MAX810L/M/R/S/T/Z Selector Guide 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 V CC below 1V. However, in applications where RESET must be valid down to 0V, 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; 100k is large enough not to load RESET and small enough to pull RESET to ground. A 100k pull-up resistor to VCC is also recommended for the MAX810 MAX810 if RESET is required to remain valid for VCC < 1V. Interfacing to µPs with Bidirectional Reset Pins Since the RESET output on the MAX803 MAX803 is open drain, this device interfaces easily with µPs that have bidirectional reset pins, such as the Motorola 68HC11 68HC11. Connecting the µP supervisor's RESET output directly to the microcontroller's (µC's) RESET pin with a single pull-up resistor allows either device to assert reset (Figure 3). MAX803 MAX803 Open-Drain RESET Output Allows Use with Multiple Supplies Generally, the pull-up connected to the MAX803 MAX803 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 MAX803 MAX803's VCC decreases 400 MAXIMUM TRANSIENT DURATION (µs) MAX803L/M/R/S/T/Z MAX803L/M/R/S/T/Z, MAX809J/L/M/R/S/T/Z MAX809J/L/M/R/S/T/Z, MAX810L/M/R/S/T/Z MAX810L/M/R/S/T/Z 3-Pin Microprocessor Reset Circuits TA = +25°C 320 VCC 240 MAX809 MAX809 RESET 160 MAX8_ _J/L/M 80 R1 100k GND MAX8_ _R/S/T/Z 0 1 10 100 1000 RESET COMPARATOR OVERDRIVE, VTH - VCC (mV) Figure 2. RESET Valid to VCC = Ground Circuit Figure 1. Maximum Transient Duration Without Causing a Reset Pulse vs. Reset Comparator Overdrive +5.0V +3.3V VCC VCC VCC VCC VCC µP MAX803 MAX803 RESET RESET INPUT RPULLUP 5V SYSTEM MAX803 MAX803 RESET MOTOROLA 68HCXX 68HCXX RESET INPUT GND GND Figure 3. Interfacing to µPs with Bidirectional Reset I/O 6 GND GND Figure 4. MAX803 MAX803 Open-Drain RESET Output Allows Use with Multiple Supplies _ 3-Pin Microprocessor Reset Circuits The MAX8_ _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. 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%, this leaves a zone of uncertainty where the supply is between 5% and 10% low, and where the reset may or may not be asserted. _Chip Information TRANSISTOR COUNT: 275 (SOT23) 380 (SC70) SC70, 3L.EPS Package Information _ 7 MAX803L/M/R/S/T/Z MAX803L/M/R/S/T/Z, MAX809J/L/M/R/S/T/Z MAX809J/L/M/R/S/T/Z, MAX810L/M/R/S/T/Z MAX810L/M/R/S/T/Z below 1V, so does the IC's ability to sink current at RESET. Also, with any pull-up, 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. Package Information (continued) SOTPO3L.EPS MAX803L/M/R/S/T/Z MAX803L/M/R/S/T/Z, MAX809J/L/M/R/S/T/Z MAX809J/L/M/R/S/T/Z, MAX810L/M/R/S/T/Z MAX810L/M/R/S/T/Z 3-Pin Microprocessor Reset Circuits 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 © 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.