MAX6836HXSD3+

MAX6832–MAX6840 Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits General Description The MAX6832–MAX6840 are microprocessor (µP) supervisory circuits used to monitor low-voltage power supplies in µP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +1.2V to +1.8V powered circuits. These devices assert a reset signal whenever the VCC supply voltage declines below a preset threshold or whenever manual reset (MR) is asserted. Reset remains asserted for a fixed timeout delay after VCC has risen above the reset threshold or when manual reset is deasserted. Five different timeout periods are available: 70µs (voltage detector), 1.5ms, 30ms, 210ms, and 1.68s. Reset thresholds suitable for operation with a variety of supply voltages are available. The MAX6832/MAX6835/MAX6838 have a push-pull active-low reset output (RESET). The MAX6833/ MAX6836/MAX6839 have a push-pull active-high reset output (RESET) and the MAX6834/MAX6837/MAX6840 have an open-drain active-low reset output (RESET). The open-drain active-low reset output requires a pullup resistor that can be connected to a voltage higher than VCC. The MAX6835/MAX6836/MAX6837 feature a debounced manual reset input (MR), while the MAX6838/MAX6839/ MAX6840 provide a RESET-IN input allowing the user to externally adjust the reset threshold. The reset comparator is designed to ignore fast transients on VCC. Low supply current of 7.5µA makes the MAX6832– MAX6840 ideal for use in portable equipment. These devices are available in 3- and 4-pin SC70 packages. Features o Factory-Set Reset Threshold Voltages for Nominal Supplies from 1.2V to 1.8V o Low Power Consumption: 7.5µA (typ) o Space-Saving 3- and 4-Pin SC70 Packages o ±2.5% Reset Threshold Accuracy Over Temperature o Five Different Timeout Periods Available: 70µs (voltage detector), 1.5ms, 30ms, 210ms, and 1.68s o Three Reset Output Configurations Push-Pull RESET Push-Pull RESET Open-Drain RESET o Guaranteed Reset Valid to VCC = 0.55V—Active-Low 0.75V—Active-High o Adjustable Threshold Reset-In Option o Manual Reset Input Option o Immune to Short Negative VCC Transients o Pin Compatible with MAX803/MAX809/MAX810, MAX6711/MAX6712/MAX6713, and MAX6381–MAX6390 Series Ordering Information PART TEMP RANGE PIN-PACKAGE MAX6832_XRD_-T -40°C to +85°C 3 SC70-3 MAX6833_XRD_-T -40°C to +85°C 3 SC70-3 MAX6834_XRD_-T -40°C to +85°C 3 SC70-3 MAX6835_XSD_-T -40°C to +85°C 4 SC70-4 MAX6836_XSD_-T -40°C to +85°C 4 SC70-4 MAX6837_XSD_-T -40°C to +85°C 4 SC70-4 Critical µP and µC Power Monitoring MAX6838XSD_-T -40°C to +85°C 4 SC70-4 Portable/Battery-Powered Equipment MAX6839XSD_-T -40°C to +85°C 4 SC70-4 MAX6840XSD_-T -40°C to +85°C 4 SC70-4 Applications Computers Controllers Intelligent Instruments Pin Configurations, Typical Operating Circuit, and Selector Guide appear at end of data sheet. Visit www.maximintegrated.com/products/patents for product patent marking information. Insert the desired suffix letter from the Threshold Suffix Guide (MAX6832–MAX6837) and the Active Timeout Period Guide tables into the blanks to complete the part number. Sample stock is generally available on standard versions only (see Standard Versions table). Standard versions require a minimum order increment of 2.5k units. Nonstandard versions must be ordered in 10k unit increments. Contact factory for availability. All parts are offered in tape-and-reel only. Devices are available in both leaded and lead-free packaging. Specify lead-free by replacing “-T” with “+T” when ordering. For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com. 19-2242; Rev 2; 12/05 MAX6832–MAX6840 Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits ABSOLUTE MAXIMUM RATINGS Terminal Voltage (with respect to GND) VCC ........................................................................-0.3V to +6.0V Open-Drain RESET, MR .......................................-0.3V to +6.0V RESET-IN, Push-Pull RESET and RESET ..............................................-0.3V to (VCC + 0.3V) Input/Output Current (all pins) ............................................20mA Continous Power Dissipation (TA = +70°C) 3-Pin SC70 (derate 2.9mW/°C above +70°C) ...............235mW 4-Pin SC70 (derate 3.1mW/°C above +70°C) ...............245mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°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 = +0.55V to +3.6V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Supply Voltage Range Supply Current SYMBOL VCC ICC CONDITIONS MIN VTH RESET-IN Threshold VRSTIN RESET-IN Leakage Current IRSTIN Reset Threshold Hysteresis VHYS 0.55 3.6 TA = -40°C to +85°C MAX6833/MAX6836/MAX6839 0.85 3.6 TA = 0°C to +85°C MAX6833/MAX6836/MAX6839 0.75 3.6 VCC = 1.2V, no load, reset not asserted 7.5 13 VCC = 1.8V, no load, reset not asserted 9 16 16 25 W 1.620 1.665 1.710 V 1.530 1.575 1.620 I 1.350 1.388 1.425 H 1.275 1.313 1.350 G 1.080 1.110 1.140 F (Note 2) 1.020 1.050 1.080 1.1V ≤ VCC ≤ 3.3V, 0°C to +85°C -2.5% 444 +2.5% 1.1V ≤ VCC ≤ 3.3V, -40°C to +85°C -3.0% 444 +3.0% -25 VCC falling, step signal from (VTH + 100mV) to (VTH - 100mV) VCC or RESET-IN to Reset Delay D0 Reset Active Timeout Period 2 tRP MAX TA = -40°C to +85°C MAX6832/MAX6835/MAX6838 MAX6834/MAX6837/MAX6840 VCC = 3.6V, no load, reset not asserted Reset Threshold TYP +25 UNITS V µA V mV nA 0.75 %VTH 60 µs 0.07 D1 1 1.5 2 D2 20 30 40 D3 140 210 280 D4 1120 1680 2240 ms Maxim Integrated MAX6832–MAX6840 Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits ELECTRICAL CHARACTERISTICS (continued) (VCC = +0.55V to +3.6V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Propagation Delay (D0 only) SYMBOL tP Startup Time (D0 only) MR Input Voltage CONDITIONS VCC rising from 0 to 1.1V (tR < 1µs) 150 VIL VIH MR driven from VCC to 0 MR to Reset Delay MR driven from VCC to 0 MR Pullup Resistance To VCC ILKG ns 500 20 ns 26 VCC ≥ 0.55V, ISINK =15µA, reset asserted 0.15 VCC ≥ 1.0V, ISINK = 80µA, reset asserted 0.15 VCC ≥ 1.5V, ISINK = 200µA, reset asserted 0.2 VCC > VTH, reset not asserted 1.0 VCC ≥ 0.55V, ISINK = 15µA, reset asserted 0.2 x VCC VCC ≥ 1.0V, ISINK = 80µA, reset asserted 0.2 x VCC VCC ≥ 1.5V, ISINK = 200µA, reset asserted 0.2 x VCC VOH VCC ≥ 1.1V, ISOURCE = 50µA, reset not asserted 0.8 x VCC VCC ≥ 1.5V, ISOURCE = 150µA, reset asserted 0.8 x VCC VCC ≥ 0.75V, ISOURCE = 10µA, reset asserted (Note 2) 0.8 x VCC VOH VOL VCC ≥ 0.85V, ISOURCE = 10µA, reset asserted 0.8 x VCC VCC ≥ 1.0V, ISOURCE = 50µA, reset asserted 0.8 x VCC VCC ≥ 1.5V, ISOURCE = 150µA, reset asserted 0.8 x VCC V µs 100 VOL Push-Pull RESET Output Voltage Push-Pull RESET Output Voltage µs 2 14 UNITS µs 0.7 x VCC MR driven from VCC to 0 VOL MAX 0.3 x VCC MR Glitch Rejection Open-Drain RESET Output Leakage Current TYP 70 MR Minimum Input Pulse Width Open-Drain RESET Output Voltage MIN VCC rising, step signal from (VTH - 100mV) to (VTH + 100mV) kΩ V µA V V VCC ≥ 1.1V, ISINK = 80µA, reset not asserted 0.2 x VCC VCC ≥ 1.5V, ISINK = 200µA, reset not asserted 0.2 x VCC Note 1: 100% production tested at +25°C. Over temperature limits are guaranteed by design. Note 2: Temperature range is from 0°C to +85°C. Maxim Integrated 3 MAX6832–MAX6840 Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits Typical Operating Characteristics (VCC = full range and TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C). VCC = 3.6V 14 VCC = 2.5V 10 VCC = 1.8V 8 VCC = 1.5V 6 4 2 VOD = OVERDRIVE (mV) 250 200 VOD = 10mV 150 VOD = 20mV 100 VOD = 100mV 50 VCC = 0.55V 0 VOD = 200mV 0 -40 -20 0 20 40 TEMPERATURE (°C) 60 80 -40 1.04 D1 OPTION 1.00 D2 OPTION 0.98 0.96 1.003 NORMALIZED RESET THRESHOLD MAX6832-40 toc03 NORMALIZED RESET TIMEOUT PERIOD 20 40 60 80 NORMALIZED RESET THRESHOLD vs. TEMPERATURE 1.06 VTH = 1.665V 1.002 1.001 1.000 0.999 0.998 0.997 0.996 0.995 0.94 0.994 -40 -20 0 20 40 TEMPERATURE (°C) 4 0 TEMPERATURE (°C) NORMALIZED POWER-UP RESET TIMEOUT vs. TEMPERATURE 1.02 -20 MAX6832-40 toc04 SUPPLY CURRENT (µA) VCC = 3.0V 12 300 POWER-DOWN RESET DELAY (µs) MAX6832-40 toc01 16 MAX6832-40 toc02 POWER-DOWN RESET DELAY vs. TEMPERATURE SUPPLY CURRENT vs. TEMPERATURE 60 80 -40 -20 0 20 40 60 80 TEMPERATURE (°C) Maxim Integrated MAX6832–MAX6840 Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits Pin Description—MAX6832–MAX6837 PIN MAX6833 SC70-3 MAX6832/ MAX6834 SC70-3 MAX6836 SC70-4 MAX6835/ MAX6837 SC70-4 NAME 1 1 1 1 GND — 2 2 — — 2 2 — FUNCTION Ground RESET Reset Output, Open-Drain or Push-Pull, Active-Low. RESET changes from HIGH to LOW when VCC drops below the selected reset threshold or MR is pulled low. RESET remains LOW for the reset timeout period after VCC exceeds the device reset threshold and MR is released high. RESET Reset Output, Push-Pull, Active-High. RESET changes from LOW to HIGH when the VCC input drops below the selected reset threshold or MR is pulled low. RESET remains HIGH for the reset timeout period after VCC exceeds the device reset threshold and MR is released high. — — 3 3 MR Active-Low Manual Reset Input. Internal 20kΩ pullup to VCC. Pull LOW to force a reset. Reset remains active as long as MR is LOW and for the reset timeout period after MR goes HIGH. Leave unconnected or connect to VCC if unused. 3 3 4 4 VCC Supply Voltage and Monitored Supply Pin Description—MAX6838/MAX6839/MAX6840 PIN MAX6839 SC70-4 MAX6838/ MAX6840 SC70-4 NAME FUNCTION Adjustable Reset Threshold Input. High-impedance input for reset comparator. Connect this pin to an external resistive-divider network to set the reset threshold voltage; the typical threshold is 444mV. Reset is asserted when RESET-IN is below the threshold (VCC is not monitored). 1 1 RESET-IN 2 2 VCC 3 3 GND 4 — RESET Reset Output, Push-Pull, Active-High. RESET changes from LOW to HIGH when the RESET-IN input drops below the typical reset threshold (444mV). RESET remains HIGH for the reset timeout period after RESET-IN exceeds the reset threshold. — 4 RESET Reset Output, Open-Drain or Push-Pull, Active-Low. RESET changes from HIGH to LOW when RESET-IN drops below the typical reset threshold (444mV). RESET remains LOW for the reset timeout period after RESET-IN exceeds the reset threshold. Maxim Integrated Supply Voltage (1.1V to 3.3V) Ground 5 MAX6832–MAX6840 Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits Functional Diagrams MR (MAX6835/MAX6836/MAX6837 ONLY) VCC VCC MR PULLUP MANUAL RESET DETECT RESET TIMEOUT PERIOD RESET-IN RESET TIMEOUT PERIOD RESET OUTPUT RESET/ RESET VREF = 444mV VREF = 444mV RESET/ RESET RESET OUTPUT MAX6838/ MAX6839/ MAX6840 MAX6832– MAX6837 GND GND Detailed Description Reset Output A microprocessor’s (µP’s) reset input starts the µP in a known state. The MAX6832–MAX6840 assert a reset to prevent code-execution errors during power-up, powerdown, or brownout conditions. They also assert a reset signal whenever the VCC supply voltage falls below a preset threshold (MAX6832–MAX6837) or RESET-IN falls below the adjustable threshold (MAX6838/ MAX6839/MAX6840), keeping reset asserted for a fixed timeout delay (Table 2) after VCC or RESET-IN has risen above the reset threshold. The MAX6832/MAX6835/ MAX6838 use a push-pull active-low output, the MAX6833/MAX6836/MAX6839 have a push-pull activehigh output, and the MAX6834/MAX6837/MAX6840 have an open-drain active-low output stage. Connect a pullup resistor on the MAX6834/MAX6837/MAX6840’s RESET output to any supply between 0 and 6V. 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. RESET-IN Information The MAX6838/MAX6839/MAX6840 feature a RESET-IN input for monitoring supply voltages down to 0.44V. An external resistive-divider network can be used to set voltage monitoring thresholds as shown in Figure 1. As the monitored voltage falls, the voltage at RESET-IN decreases and asserts a reset when it falls below the RESET-IN threshold (VRSTIN). The low-leakage current VMONITORED R1 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 a fixed timeout delay 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 CMOS logic level, 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 6 VCC MAX6838/ MAX6839/ MAX6840 RESET (RESET) RESET-IN R2 GND ( ) ARE FOR MAX6839 R1 = R2 [(VMONITORED/VREF) -1] WHERE VMONITORED IS THE DESIRED TRIP LEVEL, VREF = 444mV Figure 1. Setting the Adjustable Threshold Externally Maxim Integrated MAX6832–MAX6840 Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits at RESET-IN allows for relatively large-value resistors to be used, which reduce power consumption. For example, for a 0.6V monitored trip level, if R2 = 200kΩ, then R1 = 70.3kΩ. Note that the minimum VCC of 1.1V is required to guarantee the RESET-IN threshold accuracy (see Electrical Characteristics table). Applications Information Negative-Going VCC Transients In addition to issuing a reset to the µP during power-up, power-down, and brownout conditions, the MAX6832– MAX6840 are relatively immune to short-duration negative-going VCC transients (glitches). Figure 2 shows typical transient duration vs. reset comparator overdrive, for which the MAX6832–MAX6840 do not generate a reset pulse. The graph was generated using a negative-going pulse applied to VCC, starting 0.1V 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. 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 0.55V, the MAX6832/MAX6835/ MAX6838 push-pull RESET output no longer sinks current—it becomes an open circuit. Therefore, highimpedance CMOS logic inputs connected to RESET MAXIMUM TRANSIENT DURATION vs. OVERDRIVE can drift to undetermined voltages. This presents no problem in most applications since most µP and other circuitry are inoperative with VCC lower than 0.55V. However, in applications where RESET must be valid down to 0, adding a pulldown resistor to RESET causes any stray leakage currents to flow to ground, holding RESET low (Figure 3). R3’s value is not critical; 100kΩ is large enough not to load RESET and small enough to pull RESET to ground. A 100kΩ pullup resistor to VCC is also recommended for the MAX6833/MAX6836/MAX6839 if RESET is required to remain valid for VCC < 0.85V. VCC MAX6832 MAX6835 MAX6838 RESET R3 100kΩ GND Figure 3. RESET Valid to VCC = Ground Circuit Interfacing to µPs with Bidirectional Reset Pins Since the RESET output on the MAX6834/MAX6837/ MAX6840 is open-drain, these devices interface easily with µPs that have bidirectional reset pins. Connecting the µP supervisor’s RESET output directly to the µP’s RESET pin with a single pullup resistor allows either device to assert a reset (Figure 4). MAXIMUM TRANSIENT DURATION (µs) 900 VCC 800 700 VCC VCC 600 RESET OCCURS ABOVE THIS LINE 500 400 MAX6834 MAX6837 MAX6840 300 BIDIRECTIONAL µP RESET RESET INPUT 200 100 0 1 10 100 GND GND OVERDRIVE VTH - VCC (mV) Figure 2. Maximum Transient Duration Without Causing a Reset Pulse vs. Reset Comparator Overdrive Maxim Integrated Figure 4. Interfacing to µPs with Bidirectional Reset I/O 7 MAX6832–MAX6840 Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits Using The MAX6834/MAX6837/MAX6840 Open-Drain RESET Output with Multiple Supplies Generally, the pullup connected to the MAX6834/ MAX6837/MAX6840 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 levelshift from the monitored supply to reset circuitry powered by some other supply (Figure 5). Note that as the MAX6834/MAX6837/MAX6840’s V CC decreases, so does the IC’s ability to sink current at RESET. Also, with any pullup, RESET will be pulled high as VCC declines toward 0. The voltage where this occurs depends on the pullup resistor value and the voltage to which it is connected. Table 1. Threshold Suffix Guide SUFFIX RESET THRESHOLD (V) W 1.665 V 1.575 I 1.388 H 1.313 G 1.110 F 1.050 Table 2. Active Timeout Period Guide SUFFIX TYPICAL RESET ACTIVE TIMEOUT PERIOD (ms) D0 0.07 D1 1.5 +5.0V +1.2V VCC VCC RPULLUP MAX6834 MAX6837 MAX6840 RESET GND 5V SYSTEM RESET INPUT GND Chip Information TRANSISTOR COUNT: 681 PROCESS: BiCMOS D2 30 D3 210 D4 1680 Table 3. Standard Versions Figure 5. Using The MAX6834/MAX6837/MAX6840 Open-Drain RESET Output with Multiple Supplies 8 Selector Guide DEVICE TOP MARK MAX6832VXRD0 AIQ MAX6832VXRD3 AIR MAX6832HXRD0 AIS MAX6832HXRD3 AIT MAX6832FXRD0 AIU MAX6832FXRD3 AIV MAX6833VXRD0 AHJ MAX6833VXRD3 AIW MAX6833HXRD0 AIX MAX6833HXRD3 AIY MAX6833FXRD0 AIZ MAX6833FXRD3 AJA MAX6834VXRD0 AJB MAX6834VXRD3 AJC MAX6834HXRD0 AJD MAX6834HXRD3 AJE MAX6834FXRD0 AJF MAX6834FXRD3 AJG MAX6835VXSD0 AEX Maxim Integrated MAX6832–MAX6840 Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits Pin Configurations TOP VIEW GND GND 1 MAX6832 MAX6833 MAX6834 RESET (RESET) 3 2 4 1 MAX6835 MAX6836 MAX6837 VCC 2 RESET (RESET) 3 SC70-3 VCC RESET-IN MR VCC RESET (RESET) 2 3 GND SC70-4 ( ) ARE FOR MAX6836 Typical Operating Circuit 4 MAX6838 MAX6839 MAX6840 SC70-4 ( ) ARE FOR MAX6833 1 ( ) ARE FOR MAX6839 Selector Guide (continued) Table 3. Standard Versions (continued) VIN 3.3V DEVICE 1.2V DC/DC CONVERTER VCC RESET CORE SUPPLY RESET I/O SUPPLY µP MAX6834G/F GND GND Maxim Integrated TOP MARK MAX6835VXSD3 AFF MAX6835HXSD0 AFG MAX6835HXSD3 AFH MAX6835FXSD0 AFI MAX6835FXSD3 AFJ MAX6836VXSD0 AFK MAX6836VXSD3 AFL MAX6836HXSD0 AFM MAX6836HXSD3 AFN MAX6836FXSD0 AFO MAX6836FXSD3 AFP MAX6837VXSD0 AFQ MAX6837VXSD3 AFR MAX6837HXSD0 AFS MAX6837HXSD3 AFT MAX6837FXSD0 AFU MAX6837FXSD3 AFC MAX6838XSD0 AFW MAX6838XSD3 AFV MAX6839XSD0 AFX MAX6839XSD3 AEZ MAX6840XSD0 AFY MAX6840XSD3 AFZ 9 MAX6832–MAX6840 Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. 10 Maxim Integrated MAX6832–MAX6840 Ultra-Low-Voltage SC70 Voltage Detectors and µP Reset Circuits Package Information (continued) For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 ________________________________ 11 © 2005 Maxim Integrated Products, Inc. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.