MAX812SEUS+TG035

Click here for production status of specific part numbers. MAX811/MAX812 4-Pin μP Voltage Monitors with Manual Reset Input General Description The MAX811/MAX812 are low-power microprocessor (μP) supervisory circuits used to monitor power supplies in μP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with 5Vpowered or 3V-powered circuits. The MAX811/MAX812 also provide a debounced manual reset input. These devices perform a single function: They assert a reset signal whenever the VCC supply voltage falls below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold. The only difference between the two devices is that the MAX811 has an active-low RESET output (which is guaranteed to be in the correct state for VCC down to 1V), while the MAX812 has an active-high RESET output. The reset comparator is designed to ignore fast transients on VCC. Reset thresholds are available for operation with a variety of supply voltages. Low supply current makes the MAX811/MAX812 ideal for use in portable equipment. The devices come in a 4-pin SOT143 package. Applications Benefits and Features ●● Integrated Voltage Monitor Increases System Robustness with Added Manual Reset • Precision Monitoring of 3V, 3.3V, and 5V Power-Supply Voltages • 140ms Min Power-On-Reset Pulse Width • RESET Output (MAX811), RESET Output (MAX812) • Guaranteed Over Temperature • Guaranteed RESET Valid to VCC = 1V (MAX811) • Power-Supply Transient Immunity ●● Saves Board Space • No External Components • 4-Pin SOT143 Package ●● Low Power Consumption Simplifies Power-Supply Requirements • 6μA Supply Current Ordering Information PART* TEMP RANGE PIN-PACKAGE MAX811_EUS-T -40°C to +85°C 4 SOT143 MAX812_EUS-T -40°C to +85°C 4 SOT143 *This part offers a choice of five different reset threshold voltages. Select the letter corresponding to the desired nominal reset threshold voltage, and insert it into the blank to complete the part number. Devices are available in both leaded and lead(Pb)-free packaging. Specify lead-free by replacing “-T” with “+T” when ordering. ●● Computers ●● Controllers ●● Intelligent Instruments ●● Critical μP and μC Power Monitoring RESET THRESHOLD ●● Portable/Battery-Powered Equipment Typical Operating Circuit SUFFIX VOLTAGE (V) L 4.63 M 4.38 T 3.08 S 2.93 R 2.63 Pin Configuration VCC TOP VIEW MR VCC VCC MAX811 MAX812 µP RESET (RESET) GND PUSHBUTTON SWITCH 19-0411; Rev 6; 5/18 RESET INPUT GND 1 4 VCC 3 MR MAX811 MAX812 (RESET) RESET 2 GND ( ) ARE FOR MAX812 SOT143 ( ) ARE FOR MAX812 NOTE: SEE PACKAGE INFORMATION FOR MARKING INFORMATION. MAX811/MAX812 4-Pin μP Voltage Monitors with Manual Reset Input Absolute Maximum Ratings Terminal Voltage (with respect to GND) VCC. ....................................................................-0.3V to 6.0V All Other Inputs...................................... -0.3V to (VCC + 0.3V) Input Current, VCC, MR.......................................................20mA Output Current, RESET or RESET.....................................20mA Continuous Power Dissipation (TA = +70°C) SOT143 (derate 4mW/°C above +70°C)......................320mW Operating Temperature Range............................ -40°C to +85°C Junction Temperature.......................................................+150°C Storage Temperature Range............................. -65°C to +160°C Lead Temperature (soldering, 10sec).............................. +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 for L/M versions, VCC = 3.3V for T/S versions, VCC = 3V for R version, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL Operating Voltage Range VCC Supply Current ICC CONDITIONS TA = 0°C to +70°C TA = -40°C to +85°C MAX81_R/S/T, VCC = 3.6V, IOUT = 0 MAX81_M VTH MAX81_T MAX81_S MAX81_R Reset Threshold Tempco Reset Active Timeout Period MR Minimum Pulse Width MR Glitch Immunity (Note 3) MR to Reset Propagation Delay (Note 2) tRP tMR MR Pull-Up Resistance VIL VIH VIL VOH RESET Output Voltage (MAX812) www.maximintegrated.com 4.54 TA = +25°C 4.30 TA = +25°C 3.03 TA = +25°C 2.88 TA = +25°C 2.58 TA = -40°C to +85°C 4.50 TA = -40°C to +85°C 4.25 TA = -40°C to +85°C 3.00 TA = -40°C to +85°C 2.85 TA = -40°C to +85°C 2.55 VOL VCC > VTH(MAX), MAX81_L/M VCC > VTH(MAX), MAX81_R/S/T 6 15 2.7 10 4.63 4.72 UNITS V µA 4.75 4.38 4.46 4.50 3.08 3.14 3.15 2.93 V 2.98 3.00 2.63 2.68 2.70 ppm/°C 40 µs 20 140 560 10 ms µs 100 ns 0.5 µs 2.3 0.8 0.7 x VCC 10 ISOURCE = 150µA, 1.8V < VCC < VTH(MIN) 5.5 30 tMD VIH MR Input Threshold TA = +25°C VOD = 125mV, MAX81_R/S/T VCC = VTH(MAX) MAX 1.2 VOD = 125mV, MAX81_L/M VCC to Reset Delay (Note 2) TYP 1.0 MAX81_L/M, VCC = 5.5V, IOUT = 0 MAX81_L Reset Threshold MIN 20 0.25 x VCC 30 V kΩ 0.8 x VCC MAX812R/S/T only, ISINK = 1.2mA, VCC = VTH(MAX) 0.3 MAX812L/M only, ISINK = 3.2mA, VCC = VTH(MAX) 0.4 V Maxim Integrated │  2 MAX811/MAX812 4-Pin μP Voltage Monitors with Manual Reset Input Electrical Characteristics (continued) (VCC = 5V for L/M versions, VCC = 3.3V for T/S versions, VCC = 3V for R version, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL VOL RESET Output Voltage (MAX811) VOH CONDITIONS MIN TYP MAX MAX811R/S/T only, ISINK = 1.2mA, VCC = VTH(MIN) 0.3 MAX811L/M only, ISINK = 3.2mA, VCC = VTH(MIN) 0.4 ISINK = 50µA, VCC > 1.0V 0.3 MAX811R/S/T only, ISOURCE = 500µA, VCC > VTH(MAX) 0.8 x VCC MAX811L/M only, ISOURCE = 800µA, VCC > VTH(MAX) VCC - 1.5 UNITS V Note 1: Production testing done at TA = +25°C, over temperature limits guaranteed by design using six sigma design limits. Note 2: RESET output for MAX811, RESET output for MAX812. Note 3: “Glitches” of 100ns or less typically will not generate a reset pulse. www.maximintegrated.com Maxim Integrated │  3 MAX811/MAX812 4-Pin μP Voltage Monitors with Manual Reset Input Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) VCC = 3.3V 2.0 1.5 1.0 0.5 0 -40 -15 MAX811/12-TOC2 4 VCC = 3V 2 10 35 60 0 85 VCC = 1V -40 TEMPERATURE (°C) 10 35 TEMPERATURE (°C) POWER-DOWN RESET DELAY vs. TEMPERATURE (MAX81_R/S/T) POWER-DOWN RESET DELAY vs. TEMPERATURE (MAX81_L/M) VOD = 20mV 80 60 40 VOD = 125mV 20 -15 200 VOD = VTH - VCC VOD = 20mV 150 50 -15 10 35 60 VOD = 125mV -40 -15 10 35 60 TEMPERATURE (°C) POWER-UP RESET TIMEOUT vs. TEMPERATURE RESET THRESHOLD DEVIATION vs. TEMPERATURE MAX81_R/S/T 220 210 200 MAX81_L/M -40 -15 10 35 TEMPERATURE (°C) www.maximintegrated.com 60 85 1.0005 85 MAX811/12-TOC6 MAX811/12-TOC5 POWER-UP RESET TIMEOUT (ms) 85 VOD = 200mV TEMPERATURE (°C) 230 190 0 NORMALIZED THRESHOLD (V) -40 85 100 VOD = 200mV 0 60 MAX811/12-TOC4 VOD = VTH - VCC POWER-DOWN RESET DELAY (µs) 100 POWER-DOWN RESET DELAY (µs) VCC = 5.5V 6 VCC = 1V MAX811/12-TOC3 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) VCC = 3.6V 2.5 8 MAX811/12-TOC1 3.0 SUPPLY CURRENT vs. TEMPERATURE (MAX81_L/M) SUPPLY CURRENT vs. TEMPERATURE (MAX81_R/S/T) 1.0000 0.9995 0.9990 0.9985 0.9980 -40 -15 10 35 60 85 TEMPERATURE (°C) Maxim Integrated │  4 MAX811/MAX812 4-Pin μP Voltage Monitors with Manual Reset Input Pin Description PIN NAME FUNCTION MAX811 MAX812 1 1 GND 2 — RESET Active-Low Reset Output. RESET remains low while VCC is below the reset threshold or while MR is held low. RESET remains low for the Reset Active Timeout Period (tRP) after the reset conditions are terminated. — 2 RESET Active-High Reset Output. RESET remains high while VCC is below the reset threshold or while MR is held low. RESET remains high for Reset Active Timeout Period (tRP) after the reset conditions are terminated. Ground 3 3 MR Manual Reset Input. A logic low on MR asserts reset. Reset remains asserted as long as MR is low and for 180ms after MR returns high. This active-low input has an internal 20kΩ pull-up resistor. It can be driven from a TTL or CMOS-logic line, or shorted to ground with a switch. Leave open if unused. 4 4 VCC +5V, +3.3V, or +3V Supply Voltage Detailed Description Reset Output A microprocessor’s (μP’s) reset input starts the μP in a known state. These μP supervisory circuits assert reset to prevent code execution errors during power-up, powerdown, or brownout conditions. RESET is guaranteed to be a logic low for VCC > 1V. Once VCC exceeds the reset threshold, an internal timer keeps RESET low for the reset timeout period; after this interval, RESET goes high. If a brownout condition occurs (VCC dips below the reset threshold), RESET goes low. Any time VCC goes below the reset threshold, the internal timer resets to zero, and RESET goes low. The internal timer starts after VCC returns above the reset threshold, and RESET remains low for the reset timeout period. The manual reset input (MR) can also initiate a reset. See the Manual Reset Input section. The MAX812 has an active-high RESET output that is the inverse of the MAX811’s RESET output. www.maximintegrated.com Manual Reset Input Many μP-based products require manual reset capability, allowing the operator, a test technician, or external logic circuitry to initiate a reset. A logic low on MR asserts reset. Reset remains asserted while MR is low, and for the Reset Active Timeout Period (tRP) after MR returns high. This input has an internal 20kΩ pull-up 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. Connect a normally open momentary switch from MR to GND to create a manual-reset function; 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. Reset Threshold Accuracy The MAX811/MAX812 are ideal for systems using a 5V ±5% or 3V ±5% power supply with ICs specified for 5V ±10% or 3V ±10%, respectively. They are designed to meet worst-case specifications over temperature. The reset is guaranteed to assert after the power supply falls out of regulation, but before power drops below the minimum specified operating voltage range for the system ICs. The thresholds are pre-trimmed and exhibit tight distribution, reducing the range over which an undesirable reset may occur. Maxim Integrated │  5 MAX811/MAX812 MAXIMUM TRANSIENT DURATION (ms) 8 4-Pin μP Voltage Monitors with Manual Reset Input TA = +25°C 7 6 VCC MAX81 _L/M 5 MAX811 4 MAX81 _R/S/T 3 RESET R1 2 1 0 GND 1 10 100 1000 RESET COMPARATOR OVERDRIVE, VTH - VCC (mV) Figure 1. Maximum Transient Duration without Causing a Reset Pulse vs. Comparator Overdrive Figure 2. RESET Valid to VCC = Ground Circuit Applications Information Ensuring a Valid RESET Output Down to VCC = 0V Negative-Going VCC Transients In addition to issuing a reset to the μP during power-up, power-down, and brownout conditions, the MAX811/ MAX812 are relatively immune to short duration negativegoing VCC transients (glitches). Figure 1 shows typical transient durations vs. reset comparator overdrive, for which the MAX811/MAX812 do not generate a reset pulse. This graph was generated using a negative-going pulse applied to VCC, starting above the actual reset threshold and ending below it by the magnitude indicated (reset comparator overdrive). The graph indicates the typical maximum pulse width a negative-going VCC transient may have without causing a reset pulse to be issued. As the magnitude of the transient increases (goes farther below the reset threshold), the maximum allowable pulse width decreases. Typically, a VCC transient that goes 125mV below the reset threshold and lasts 40μs or less (MAX81_L/M) or 20μs or less (MAX81_T/S/R) will not cause a reset pulse to be issued. A 0.1μF capacitor mounted as close as possible to VCC provides additional transient immunity. www.maximintegrated.com When VCC falls below 1V, the MAX811 RESET output no longer sinks current—it becomes an open circuit. Therefore, high-impedance CMOS-logic inputs connected to the RESET output 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 the RESET output must be valid down to 0V, adding a pulldown resistor to the RESET pin will cause 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 MAX812 if RESET is required to remain valid for VCC < 1V. Maxim Integrated │  6 MAX811/MAX812 4-Pin μP Voltage Monitors with Manual Reset Input Interfacing to μPs with Bidirectional Reset Pins μPs with bidirectional reset pins (such as the Motorola 68HC11 series) can contend with the MAX811/MAX812 reset outputs. If, for example, the MAX811 RESET output is asserted high and the μP wants to pull it low, indeterminate logic levels may result. To correct such cases, connect a 4.7kΩ resistor between the MAX811 RESET (or MAX812 RESET) output and the μP reset I/O (Figure 3). Buffer the reset output to other system components. BUFFER VCC VCC MAX811 RESET GND BUFFERED RESET TO OTHER SYSTEM COMPONENTS 4.7k µP RESET GND Chip Information TRANSISTOR COUNT: 341 www.maximintegrated.com Figure 3. Interfacing to μPs with Bidirectional Reset I/O Maxim Integrated │  7 MAX811/MAX812 4-Pin μP Voltage Monitors with Manual Reset Input 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 PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 4 SOT143 U4+1 21-0052 90-0183 www.maximintegrated.com Maxim Integrated │  8 MAX811/MAX812 4-Pin μP Voltage Monitors with Manual Reset Input Revision History REVISION NUMBER REVISION DATE PAGES CHANGED DESCRIPTION 5 6/15 Updated Benefits and Features and Package Information sections 6 5/18 Updated Absolute Maximum Ratings 1, 8 2 For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https://www.maximintegrated.com/en/storefront/storefront.html. 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. ©  2018 Maxim Integrated Products, Inc. │  9