19-0539; Rev 5; 9/08 Microprocessor Voltage Monitors with Programmable Voltage Detection ____________________________Features Maxim’s MAX8211 and MAX8212 are CMOS micropower voltage detectors that warn microprocessors (µPs) of power failures. Each contains a comparator, a 1.5V bandgap reference, and an open-drain n-channel output driver. Two external resistors are used in conjunction with the internal reference to set the trip voltage to the desired level. A hysteresis output is also included, allowing the user to apply positive feedback for noise-free output switching. The MAX8211 provides a 7mA current-limited output sink whenever the voltage applied to the threshold pin is less than the 1.5V internal reference. In the MAX8212, a voltage greater than 1.5V at the threshold pin turns the output stage on (no current limit). o µP Power-Fail Warning o Improved 2nd Source for ICL8211/ICL8212 o Low-Power CMOS Design The CMOS MAX8211/MAX8212 are plug-in replacements for the bipolar ICL8211/ICL8212 in applications where the maximum supply voltage is less than 16.5V. They offer several performance advantages, including reduced supply current, a more tightly controlled bandgap reference, and more available current from the hysteresis output. o o o o o o 5µA Quiescent Current On-Board Hysteresis Output ±40mV Threshold Accuracy (±3.5%) 2.0V to 16.5V Supply-Voltage Range Define Output Current Limit (MAX8211) High Output Current Capability (MAX8212) _______________Ordering Information TEMP RANGE PINPACKAGE MAX8211CPA -0°C to +70°C 8 Plastic DIP MAX8211CSA -0°C to +70°C 8 SO MAX8211CUA -0°C to +70°C 8 µMAX MAX8211CTY -0°C to +70°C 8 TO-99 MAX8211EPA -40°C to +85°C 8 Plastic DIP µP Voltage Monitoring MAX8211ESA -40°C to +85°C 8 SO Undervoltage Detection MAX8211EJA -40°C to +85°C 8 CERDIP MAX8211ETY -40°C to +85°C 8 TO-99 MAX8211MJA -55°C to +125°C 8 CERDIP** ________________________Applications Overvoltage Detection Battery-Backup Switching PART Ordering Information continued on last page. *Contact factory for dice specifications. **Contact factory for availability and processing to MIL-STD-883. Power-Supply Fault Monitoring Low-Battery Detection _________________Pin Configurations ___________Typical Operating Circuit V+ TOP VIEW R3 V+ N.C. 1 HYST 2 THRESH 3 OUT 4 MAX8211 MAX8212 8 V+ 7 N.C. 6 N.C. 5 GND HYST OUT R2 µP NMI MAX8211 THRESH GND R1 DIP/SO Pin Configurations continued at end of data sheet. LOGIC-SUPPLY UNDERVOLTAGE DETECTOR (DETAILED CIRCUIT DIAGRAM—FIGURE 5) ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX8211/MAX8212 ________________General Description MAX8211/MAX8212 Microprocessor Voltage Monitors with Programmable Voltage Detection ABSOLUTE MAXIMUM RATINGS Supply Voltage .......................................................-0.5V to +18V Output Voltage .......................................................-0.5V to +18V Hysteresis...................+0.5V to -18V with respect to (V+ + 0.5V) Threshold Input Voltage ...............................-0.5V to (V+ + 0.5V) Current into Any Terminal .................................................±50mA Continuous Power Dissipation (TA = +70°C) 8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) .....727mW 8-Pin SO (derate 5.88mW/°C above +70°C)..................471mW 8-Pin CERDIP (derate 8.00mW/°C above +70°C)..........640mW 8-Pin TO-99 (derate 6.67mW/°C above +70°C).............533mW Operating Temperature Ranges MAX821_C_ _ .......................................................0°C to +70°C MAX821_E_ _.....................................................-40°C to +85°C MAX821_M_ _ ..................................................-55°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 (V+ = 5V, TA = +25°C, unless otherwise noted.) PARAMETER Supply Current SYMBOL I+ CONDITIONS 2V ≤ V+ ≤ 16.5V, GND ≤ VTH ≤ V+ TA = +25°C Threshold Trip Voltage VTH TA = TMIN to TMAX Threshold Voltage Disparity between Output and Hysteresis Output VTHP Guaranteed Operating Supply Voltage Range VSUPP Typical Operating Supply Voltage Range VSUPP Threshold Voltage Temperature Coefficient Variation of Threshold Voltage with Supply Voltage Threshold Input Current TA = +25°C ITH 5 TA = TMIN to TMAX V+ = 16.5V, IOUT = 4mA V+ = 2V, IOUT = 500µA V+ = 16.5V, IOUT = 3mA V+ = 2.2V, IOUT = 500µA 15 5 20 20 1.19 1.11 1.19 1.05 1.25 1.05 1.25 ±0.1 ±0.1 2.0 16.5 2.0 16.5 TA = TMIN to TMAX 2.2 16.5 2.2 16.5 1.5 16.5 1.5 16.5 V V -200 -200 ppm/°C V+ = 4.5V to 5.5V 1.0 0.2 mV 0V ≤ VTH ≤ V+, TA = +25°C 0.01 TA = TMIN to TMAX 10 20 VOUT = 5V, VTH = 1.3V VOUT = 5V, VTH = 1.3V 0.01 10 20 nA 10 10 1 1 VOUT = 16.5V, VTH = 0.9V TA = TMIN to TMAX, VOUT = 16.5V, VTH = 1.3V M temp. range VOUT = 5V, VTH = 0.9V 2 mV TA = +25°C TA = TMIN to TMAX, VOUT = 16.5V, VTH = 1.3V C/E temp. ranges VOUT = 5V, VTH = 1.0V ILOUT µA V VOUT = 16.5V, VTH = 1.0V Output Leakage Current 15 1.11 IOUT = 4mA, IHYST = 1mA ∆VTH/∆T See Figure 4 ∆VTH MAX8211 MAX8212 UNITS MIN TYP MAX MIN TYP MAX 30 30 10 10 _______________________________________________________________________________________ µA Microprocessor Voltage Monitors with Programmable Voltage Detection (V+ = 5V, TA = +25°C, unless otherwise noted.) PARAMETER SYMBOL Output Saturation Voltage VOL Maximum Available Output Current IOH Hysteresis Leakage Current MAX8211 MAX8212 UNITS MIN TYP MAX MIN TYP MAX CONDITIONS IOUT = 2mA, VTH = 1.0V 0.17 0.4 IOUT = 2mA, VTH = 1.3V C temp. range, VOUT = 5V 0.17 VTH = 1.0V (Note 1) 4 0.4 7.0 VTH = 1.3V (Note 2) 12 TA = TMIN to TMAX, C/E temp. ranges, V+ = 16.5V, VTH = 1.0V, VHYST = -16.5V with respect to V+ mA 35 0.1 V 0.1 ILHYS µA TA = TMIN to TMAX, M temp. range, V+ = 16.5V, VTH = 0.9V, VHYST = -16.5V with respect to V+ Hysteresis Saturation Voltage VHYS (MAX) IHYST = 0.5mA, VTH = 1.3V, measured with respect to V+ Maximum Available Hysteresis Current VHYS (MAX) VTH = 1.3V, VHYS = 0V 3 -0.1 2 3 -0.2 10 -0.1 2 -0.2 10 V mA Note 1: The maximum output current of the MAX8211 is limited by design to 30mA under any operating condition. The output voltage may be sustained at any voltage up to +16.5V as long as the maximum power dissipation of the device is not exceeded. Note 2: The maximum output current of the MAX8212 is not defined, and systems using the MAX8212 must therefore ensure that the output current does not exceed 50mA and that the maximum power dissipation of the device is not exceeded. _______________Detailed Description As shown in the block diagrams of Figures 1 and 2, the MAX8211 and MAX8212 each contain a 1.15V reference, a comparator, an open-drain n-channel output transistor, and an open-drain p-channel hysteresis output. The MAX8211 output n-channel turns on when the voltage applied to the THRESH pin is less than the internal reference (1.15V). The sink current is limited to 7mA (typical), allowing direct drive of an LED without a series resistor. The MAX8212 output turns on when the voltage applied to THRESH is greater than the internal reference. It is not current limited, and will typically sink 35mA. V+ P THRESH HYST OUT N 1.15V REFERENCE Compatibility with ICL8211/ICL8212 The CMOS MAX8211/MAX8212 are plug-in replacements for the bipolar ICL8211/ICL8212 in most applications. The use of CMOS technology has several advantages. The quiescent supply current is much less than in the bipolar parts. Higher-value resistors can also be used Figure 1. MAX8211 Block Diagram ________________________________________________________________________________________ 3 MAX8211/MAX8212 ELECTRICAL CHARACTERISTICS (continued) MAX8211/MAX8212 Microprocessor Voltage Monitors with Programmable Voltage Detection V+ V+ VIN R2 P THRESH V+ R3 HYST HYST OUT VOUT MAX8211 MAX8212 THRESH OUT 1.15V REFERENCE N GND R1 Figure 2. MAX8212 Block Diagram Figure 3. Basic Overvoltage/Undervoltage Circuit in the networks that set up the trip voltage, since the comparator input (THRESH pin) is a low-leakage MOSFET transistor. This further reduces system current drain. The tolerance of the internal reference has also been significantly improved, allowing for more precise voltage detection without the use of potentiometers. The available current from the HYST output has been increased from 21µA to 10mA, making the hysteresis feature easier to use. The disparity between the HYST output and the voltage required at THRESH to switch the OUT pin has also been reduced in the MAX8211 from 8mV to 0.1mV to eliminate output “chatter” or oscillation. Most voltage detection circuits operate with supplies of 15V or less; in these applications, the MAX8211/ MAX8212 will replace ICL8211/ICL8212s with the performance advantages described above. However, note that the CMOS parts have an absolute maximum supply-voltage rating of 18V, and should never be used in applications where this rating could be exceeded. Exercise caution when replacing ICL8211/ICL8212s in closed-loop applications such as programmable zeners. Although neither the ICL8211/ICL8212 nor the MAX8211/MAX8212 are internally compensated, the CMOS parts have higher gain and may not be stable for the external compensation-capacitor values used in lower-gain ICL8211/ICL8212 circuits. __________Applications Information 4 Basic Voltage Detectors Figure 3 shows the basic circuit for both undervoltage detection (MAX8211) and overvoltage detection (MAX8212). For applications where no hysteresis is needed, R3 should be omitted. The ratio of R1 to R2 is then chosen such that, for the desired trip voltage at VIN, 1.15V is applied to the THRESH pin. Since the comparator inputs are very low-leakage MOSFET transistors, the MAX8211/MAX8212 can use much higher resistors values in the attenuator network than can the bipolar ICL8211/ICL8212. See Table 1 for switching delays. Table 1. Switching Delays TYPICAL DELAYS MAX8211 MAX8212 t(on) 40µs 250µs t(off) 1.5ms 3ms Voltage Detectors with Hysteresis To ensure noise-free output switching, hysteresis is frequently used in voltage detectors. For both the MAX8211 and MAX8212 the HYST output is on for threshold voltages greater than 1.15V. R3 (Figure 3) controls the amount of current (positive feedback) supplied from the HYST output to the mid-point of the resistor divider, and hence the magnitude of the hysteresis, or dead-band. ________________________________________________________________________________________ Microprocessor Voltage Monitors with Programmable Voltage Detection MAX8211/MAX8212 VIN MAX8211,8212-FIG 4 1.250 1.230 1.210 VTH (V) 1.190 R3 48.7kΩ 1% V+ V+ = 16.5V 1.170 HYST 1.150 1.130 MAX8211 R2 2.2MΩ 1% V+ = 2V 1.110 OUT VOUT (LOW FOR VIN < 4.5V) THRESH 1.090 GND R1 750kΩ 1% 1.070 1.050 -55 -25 25 75 125 TA (°C) Figure 4. MAX8211/MAX8212 Threshold Trip Voltage vs. Ambient Temperature Figure 5. MAX8211 Logic-Supply Low-Voltage Detector Calculate resistor values for Figure 3 as follows: 1) Choose a value for R1. Typical values are in the 10kΩ to 10MΩ range. 2) Calculate R2 for the desired upper trip point VU using the formula: Calculate resistor values for Figure 5 as follows: 1) Choose a value for R1. Typical values are in the 10kΩ to 10MΩ range. 2) Calculate R2: (VU − VTH ) (VU − 1.15V) R2 = R1 × = R1 × VTH 1.15V 3) Calculate R3 for the desired amount of hysteresis, where VL is the lower trip point: R3 = R2 × (V + − VTH ) (V + − 1.15V) = R2 × (VU − VL ) (VU − VL ) or, if V+ = VIN: R3 = R2 × (VL − VTH ) (VL − 1.15V) = R2 × (VU − VL ) (VU − VL ) Figure 5 shows an alternate circuit, suitable only when the voltage being detected is also the power-supply voltage for the MAX8211 or MAX8212. R2 = R1 × (VL − VTH ) (VL − 1.15V) = R1 × VTH 1.15V 3) Calculate R3: R3 = R1 × (VU − VL ) 1.15V Low-Voltage Detector for Logic Supply The circuit of Figure 5 will detect when a 5.0V (nominal) supply goes below 4.5V, which is the VMIN normally specified in logic systems. The selected resistor values ensure that false undervoltage alarms will not be generated, even with worst-case threshold trip values and resistor tolerances. R3 provides approximately 75mV of hysteresis. ________________________________________________________________________________________ 5 MAX8211/MAX8212 Microprocessor Voltage Monitors with Programmable Voltage Detection _____________________________________________Pin Configurations (continued) TOP VIEW TOP VIEW HYST 7 1 OUT 1 8 THRESH N.C. 2 7 HYST 6 N.C. 5 V+ N.C. 3 GND 4 MAX8211 MAX8212 OUT V+ 8 THRESH 6 2 3 N.C. 5 4 N.C. N.C. GND µMAX TO-99* * CASE IS CONNECTED TO PIN 7 ON TV PACKAGE. CASE IS CONNECTED TO PIN 4 ON TY PACKAGE. Package Information _Ordering Information (continued) PART MAX8211MSA/PR TEMP RANGE -55°C to +125°C PINPACKAGE For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. 8 SO** PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 8 CERDIP J8-2 21-0045 MAX8211MSA/PR-T -55°C to +125°C 8 SO** MAX8211MTV -55°C to +125°C 8 TO-99** 8 Plastic DIP P8-1 21-0043 8 SO S8-2 21-0041 MAX8212CPA -0°C to +70°C 8 Plastic DIP MAX8212CSA -0°C to +70°C 8 SO 8 TO-99 T99-8 21-0022 MAX8212CUA -0°C to +70°C 8 µMAX 8 µMAX U8-1 21-0036 MAX8212CTY -0°C to +70°C 8 TO-99 MAX8212EPA -40°C to +85°C 8 Plastic DIP MAX8212ESA -40°C to +85°C 8 SO MAX8212EJA -40°C to +85°C 8 CERDIP MAX8212ETY -40°C to +85°C 8 TO-99 MAX8212MJA -55°C to +125°C 8 CERDIP** MAX8212MSA/PR -55°C to +125°C 8 SO** MAX8212MSA/PR-T -55°C to +125°C 8 SO** MAX8212MTV -55°C to +125°C 8 TO-99** *Contact factory for dice specifications. **Contact factory for availability and processing to MIL-STD-883. 6 _______________________________________________________________________________________ Microprocessor Voltage Monitors with Programmable Voltage Detection REVISION NUMBER REVISION DATE 0 1/91 Initial release 4 9/02 Updated Figure 5. 5 9/08 Updated Ordering Information. DESCRIPTION PAGES CHANGED — 5 1, 6 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. 7 ___________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600 © 2008 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc. MAX8211/MAX8212 Revision History