MAX6806/MAX6807/ MAX6808 Voltage Detectors General Description The MAX6806/MAX6807/MAX6808 precision voltage detectors are ideal for accurate monitoring of power supplies in digital systems. They provide circuit reliability and reduce total cost by eliminating external components and adjustments. The MAX6806/MAX6807/MAX6808 assert a reset signal whenever the supply voltage (VCC) falls below the factorypreset, ±2% accurate threshold. Internal hysteresis ensures stable switching. The MAX6806/MAX6807/ MAX6808 are available in 4.6V and 2.6V thresholds (2.3V is also available for the MAX6806 only). The MAX6806 features an active-low, push-pull RESET output; the MAX6807 features an active-high, push-pull RESET output; and the MAX6808 features an active-low, opendrain RESET output. RESET is valid for VCC down to 1V (MAX6806/MAX6808), and RESET (MAX6807) is guaranteed for VCC down to 1.2V. The MAX6806/MAX6807/MAX6808 are available in 3-pin SC70, 3-pin SOT23, 8-pin µMAX, 8-pin SO, and 4-pin SOT143 packages. The SOT143 package includes a manual-reset input. Features ●● Preset Reset Thresholds: 4.6V and 2.6V (2.3V also available for MAX6806 only) ●● ±2% Accurate Reset Thresholds ●● Reset Output Available in Active-Low (MAX6806), Active-High (MAX6807), and Open-Drain (MAX6808) Versions ●● Immune to Power-Supply Transients ●● RESET Valid to VCC = 1.0V (MAX6806/MAX6808) ●● 35µA Supply Current ●● No External Components ●● Manual Reset Available with 4-Pin SOT143 Package ●● Miniature 3-Pin SC70, 3-Pin SOT23, and 4-Pin SOT143 Packages ●● 8-Pin µMAX and 8-Pin SO Packages are Pin Compatible with the MC33064/MC33164/ MC34064/MC34164 Ordering Information PART TEMP. RANGE PIN-PACKAGE MAX6806XR_ _ -T -40°C to +85°C 3 SC70 MAX6806UR_ _ -T -40°C to +85°C 3 SOT23 MAX6806US_ _ -T -40°C to +85°C 4 SOT143 MAX6806UA_ _ -40°C to +85°C 8 µMAX MAX6806SA_ _ -40°C to +85°C 8 SO Selector Guide and Pin Configurations appear at end of data sheet. MAX6807XR_ _ -T -40°C to +85°C 3 SC70 MAX6807UR_ _ -T -40°C to +85°C 3 SOT23 Typical Operating Circuit MAX6807US_ _ -T -40°C to +85°C 4 SOT143 MAX6807UA_ _ -40°C to +85°C 8 µMAX MAX6807SA_ _ -40°C to +85°C 8 SO MAX6808XR_ _ -T -40°C to +85°C 3 SC70 MAX6808UR_ _ -T -40°C to +85°C 3 SOT23 MAX6808US_ _ -T -40°C to +85°C 4 SOT143 MAX6808UA_ _ -40°C to +85°C 8 µMAX MAX6808SA_ _ -40°C to +85°C 8 SO Applications ●● ●● ●● ●● Computers Controllers Intelligent Instruments Critical µP and µC Power Monitoring ●● Portable/Battery●● Powered Equipment ●● Bar-Code Scanners VCC VCC VCC MAX6806 MAX6807 MAX6808 (RESET)/RESET GND ( ) ARE FOR MAX6807 19-1421; Rev 3; 7/14 µP RESET INPUT GND * SOT23, SOT143, and SC70s are available in tape-and-reel only, 2500 piece minimum order quantity. Note: Insert the desired number from the Selector Guide into the blank to complete the part number. Also see Selector Guide for top mark for SOT23 MAX6806/MAX6807/ MAX6808 Voltage Detectors Absolute Maximum Ratings VCC to GND .........................................................-0.3V to +6.0V RESET, RESET to GND (MAX6806/MAX6807) .............................. -0.3V to (VCC + 0.3V) RESET to GND (MAX6808).................................-0.3V to + 6.0V MR to GND (SOT143 package only)...................-0.3V to + 6.0V Input Current, VCC ...........................................................±20mA Output Current, RESET, RESET ......................................±20mA Rate of Rise, VCC ..........................................................100V/µs Continuous Power Dissipation (TA = +70°C) SOT23, SOT143 (derate 4mW/°C above +70°C) .......320mW SC70 (derate 2.17mW/°C above +70vC) ....................174mW µMAX (derate 4.5mW/°C above +70°C) .....................362mW SO (derate 5.9mW/°C above +70°C) ..........................471mW Operating Temperature Range ........................... -40°C to +85°C Storage Temperature Range............................. -65°C to +160°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, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL Supply Voltage Range VCC Supply Current ICC Reset Threshold Reset Threshold Hysteresis RESET Output Voltage (MAX6806/MAX6808) VTH- VHYST VOL CONDITIONS TA = -40°C to +85°C 1.2 5.5 VCC = +3.6V, no load 35 60 VCC = +5.5V, no load 50 80 TA = +25°C VCC falling MAX680_ _ _46 4.508 4.60 4.692 MAX680_ _ _32 3.136 3.20 3.264 MAX680_ _ _26 2.548 2.60 2.652 MAX680_ _ _23 2.254 2.30 2.346 0.02 VTH- 0.03 VTH- TA = +25°C, Figure 2 ISINK = 20µA, VCC = 1.0V 0.3 ISINK = 1.0mA, VCC = 2.0V 0.4 RESET Output Leakage Current IOH VCC = 5.5V, RESET deasserted (MAX6808 only) RESET Output Voltage (MAX6807) VOH 1 ISOURCE = 20µA, VCC = 1.2V 0.8 VCC ISOURCE = 400µA, VCC = 2.0V 0.8 VCC MR Input Threshold VIH 40 VCC > VTH+ µA V V V µA 0.4 VCC falling at 1mV/µs VIL V V ISINK = 3.2mA, VCC = 5.0V RMR UNITS 0.8 VCC Reset Threshold Tempco MR Pulldown Resistance MAX 5.5 ISOURCE = 2.0mA, VCC = 5.0V (MAX6806 only) VCC to Reset Delay (Note 2) TYP 1.0 VOH VOL MIN TA = 0°C to +70°C 30 µs 30 ppm/°C 80 120 0.6 0.7 VCC kW V Note1: All devices are 100% production tested at TA = +25°C, and are guaranteed by design for TA = TMIN to TMAX, as specified. Note 2: RESET output for MAX6806/MAX6808, RESET output for MAX6807. www.maximintegrated.com Maxim Integrated │ 2 MAX6806/MAX6807/ MAX6808 Voltage Detectors Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. TEMPERATURE 35 41 VCC = 3.3V 30 25 VCC = 1.8V 20 15 10 0 -60 -30 0 30 60 90 39 37 35 33 31 29 VCC = 1.0V 5 VOD = VTH- - VCC = 100mV VCC FALLING AT 1mV/µS 43 27 25 120 -60 -45 -30 -15 0 15 30 45 60 75 90 105 120135 TEMPERATURE (°C) TEMPERATURE (°C) POWER-UP RESET DELAY vs. TEMPERATURE 11 DELAY TIME (µs) 10 1.0100 NORMALIZED RESET THRESHOLD VOD = VCC - VTH+ MAX6806/7/8-03 12 9 VOD = 50mV 8 7 VOD = 100mV 6 5 4 VOD = 200mV -60 -30 0 30 60 90 1.0080 1.0060 VCC RISING (VTH+) 1.0040 1.0020 1.0000 0.9980 0.9960 VCC FALLING (VTH-) 0.9940 0.9920 0.9900 120 NORMALIZED RESET THRESHOLD vs. TEMPERATURE MAX6806/7/8-04 40 45 MAX6806/7/8toc02 VCC = 5.0V RESET DELAY (µs) SUPPLY CURRENT (µA) 45 MAX6806/7/8-01 50 POWER-DOWN RESET DELAY vs. TEMPERATURE -40 -30 -15 0 15 30 45 60 75 85 TEMPERATURE (°C) TEMPERATURE (°C) Pin Description PIN SOT23/SC70 1 SOT143 1 2 4 µMAX/SO NAME FUNCTION RESET Active-Low Reset Output (MAX6806/MAX6808). RESET remains low while VCC is below the reset-threshold voltage or while MR is held high. RESET Active-High Reset Output (MAX6807). RESET remains high while VCC is below the reset-threshold voltage or while MR is held high. 1 4 GND Ground 3 3 2 VCC Supply Voltage Input — 2 — MR Active-High Manual Reset Input. Internal 80kW resistor to GND. — — 3,5–8 N.C. Not Internally Connected www.maximintegrated.com Maxim Integrated │ 3 MAX6806/MAX6807/ MAX6808 Voltage Detectors Detailed Description Manual-Reset Input Reset Output The MAX6806 voltage detector features an active-low, push-pull RESET output, while the MAX6807 features an active-high, push-pull RESET output. Unlike microprocessor (µP) supervisory circuits that offer a reset timeout period, the MAX6806 and MAX6807 RESET goes high and RESET goes low virtually immediately once VCC exceeds the reset threshold. If a brownout occurs (VCC falls below the reset threshold), RESET goes low and RESET goes high. RESET is guaranteed to be a logic low for VCC ≥ 1V and RESET is guaranteed to be a logic high for VCC ≥ 1.2V. The MAX6808 features an active-low, open-drain RESET output. The output sinks current when VCC falls below the reset threshold. Connect a pullup resistor from RESET to any supply voltage up to 6V (Figure 1). Select a resistor value large enough to provide a logic low and small enough to provide a logic high while supplying all input and leakage currents connected to the RESET line. A 100kΩ resistor is sufficient in applications driving high-impedance loads. The manual reset input (MR, 4-pin SOT143 package) can also initiate a reset (see Manual Reset Input section). +3.3V +5.0V Many applications require manual-reset capabilities, allowing an operator, a test technician, or external logic circuitry to initiate a reset. A logic high on MR asserts a reset and remains asserted while MR is high. This input has an 80kΩ pulldown resistor, so the input can be left unconnected if not used. Connect a normally open momentary switch from MR to VCC to create a manual-reset function. 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 noise immunity. Hysteresis The MAX6806/MAX6807/MAX6808 feature internal hysteresis that creates two trip points: one for the rising supply voltage and one for the falling supply voltage (Figure 2). The hysteresis prevents the output from oscillating (chattering) when VCC is near the reset threshold. Reset Threshold Accuracy The MAX6806/MAX6807/MAX6808 are ideal for sys-tems using a 5V ±5%, 3V ±5%, or 2.5V ±5% power supply with ICs specified for 5V ±10%, 3V ±10%, or 2.5V ±10%, respectively. The reset is guaranteed to assert after the power supply falls out of regulation, but before power drops below the minimum specified oper-ating voltage range for the system ICs. VTH+ HYST VCC VCC MAX6808 100kΩ VHYST = VTH+ - VTH- VTH- VOH 5V SYSTEM RESET (MAX6806/MAX6808) VOL RESET VOH GND GND RESET (MAX6807) Figure 1. The MAX6808 Open-Drain RESET Output Allows Use with Multiple Supplies www.maximintegrated.com VOL Figure 2. Input and Output Waveforms with VCC Varied Maxim Integrated │ 4 MAX6806/MAX6807/ MAX6808 Voltage Detectors Applications Information Ensuring a Valid Reset Output Down to VCC = Ground Negative-Going VCC Transients In addition to asserting a reset signal during power-up, power-down, and brown-out conditions, the MAX6806/ MAX6807/MAX6808 are immune to short-duration, negative-going VCC transients. Figure 3 displays typical transient durations vs. reset-comparator overdrive for which the MAX6806/MAX6807/ MAX6808 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 further below the reset threshold), the maximum allowable pulse width decreases. A 0.1µF capacitor mounted as close as possible to VCC provides additional transient immunity. When VCC falls below 1V, the MAX6806/MAX6808 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 circuitry is inoperative when VCC is below 1V. In applications where RESET must be valid down to ground, add a pulldown resistor to RESET so any stray leakage currents flow to ground, holding RESET low (Figure 4). Select R1 to be large enough not to load RESET and small enough to pull RESET to ground. For most applications, 100kΩ will not load RESET and will pull RESET to ground. Similarly, if RESET (MAX6807) must be valid below 1.2V, add a pullup resistor to RESET. MAXIMUM TRANSIENT DURATION (µs) 80 TA = +25°C 70 VCC VCC 60 MAX6806 50 40 MAX680 46 RESET 30 20 MAX6807 R1 100kΩ RESET R1 100kΩ 10 100 1000 GND GND RESET COMPARATOR OVERDRIVE, VTH- - VCC (mV) Figure 3. Maximum Transient Duration without Causing a Reset Pulse vs. Reset Comparator Overdrive www.maximintegrated.com Figure 4. RESET / RESET Valid to VCC = Ground Circuit Maxim Integrated │ 5 MAX6806/MAX6807/ MAX6808 Voltage Detectors Interfacing to µPs with Bidirectional Reset Pins µPs with bidirectional reset pins (such as the Motorola 68HC11 series) can contend with push-pull RESET outputs, resulting in indeterminate logic levels. Use the MAX6808 with the open-drain RESET when interfacing to this type of controller. VCC VCC VCC MAX6808 RESET GND 4.7kΩ µP RESET GND Figure 5. Interfacing to μPs with Bidirectional Reset I/O Selector Guide TOP MARK NOMINAL VTH- (V)† MAX6806SA46 PART RESET OUTPUT — 4.6 MAX6806SA26 — 2.6 MAX6806SA23 — 2.3 MAX6806UA46 — 4.6 MAX6806UA26 — 2.6 MAX6806UA23 — 2.3 MAX6806UR46-T FZDP 4.6 FZDQ 2.6 FZDR 2.3 MAX6806US46-T KABT 4.6 MAX6806US26-T KABU 2.6 MAX6806US23-T KABV 2.3 MAX6806XR46-T AAA 4.6 MAX6806XR26-T AAB 2.6 MAX6806XR23-T AAC 2.3 MAX6806UR26-T MAX6806UR23-T www.maximintegrated.com Active-Low, Push-Pull Maxim Integrated │ 6 MAX6806/MAX6807/ MAX6808 Voltage Detectors Selector Guide (continued) TOP MARK NOMINAL VTH- (V) † MAX6807SA46 PART — 4.6 MAX6807SA26 — 2.6 MAX6807UA46 — 4.6 MAX6807UA26 — 2.6 FZDS 4.6 FZDT 2.6 MAX6807US46-T KABW 4.6 MAX6807US26-T KABX 2.6 MAX6807XR46-T AAD 4.6 MAX6807XR26-T MAX6807UR46-T MAX6807UR26-T RESET OUTPUT Active-High, Push-Pull AAE 2.6 MAX6808SA46 — 4.6 MAX6808SA32 — 3.2 MAX6808SA26 — 2.6 MAX6808UA46 — 4.6 MAX6808UA32 — 3.2 MAX6808UA26 — 2.6 FZDU 4.6 MAX6808UR46-T MAX6808UR32-T Active-Low, Open-Drain FZFL 3.2 FZDV 2.6 MAX6808US46-T KABY 4.6 MAX6808US32-T KACC 3.2 MAX6808US26-T KABZ 2.6 MAX6808XR46-T AAF 4.6 MAX6808XR32-T ACD 3.2 MAX6808XR26-T AAG 2.6 MAX6808UR26-T Other voltage thresholds may be available. Contact factory for availability. www.maximintegrated.com Maxim Integrated │ 7 MAX6806/MAX6807/ MAX6808 Voltage Detectors Pin Configurations TOP VIEW (RESET)/RESET 1 MAX6806 MAX6807 MAX6808 GND 2 SOT23/SC70 ( ) ARE FOR MAX6807 Chip Information TRANSISTOR COUNT: 72 (RESET)/RESET 3 1 VCC MAX6806 MAX6807 MAX6808 8 N.C. 7 N.C. VCC 2 N.C. 3 6 N.C. GND 4 5 N.C. (RESET)/RESET GND 3 VCC MAX6806 MAX6807 MAX6808 MR 2 SOT143 µMAX/SO 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. PACKAGE TYPE www.maximintegrated.com 4 1 PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 3 SC70 X3-2 21-0075 90-0208 3 SOT23 U3-1 21-0051 90-0179 4 SOT143 U4-1 21-0052 90-0183 8 SO — 21-0041 — 8 μMAX — 21-0036 — Maxim Integrated │ 8 MAX6806/MAX6807/ MAX6808 Voltage Detectors Revision History REVISION NUMBER REVISION DATE 3 7/14 PAGES CHANGED DESCRIPTION No /V OPNs; removed Automotive reference from Applications section; updated Package Information 1, 9–13 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com. 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 and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. © 2014 Maxim Integrated Products, Inc. │ 9