19-0450; Rev 3; 2/03 Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators The MAX971–MAX974 and MAX981–MAX984 single/ dual/quad low-voltage comparators feature the lowest power consumption available. These micropower devices draw less than 4µA supply current over temperature (MAX971/MAX972/MAX981/MAX982), and include an internal 1.182V ±1% (MAX971/MAX973/ MAX974) or ±2% (MAX981–MAX984) voltage reference and programmable hysteresis. Ideal for 3V or 5V single-supply applications, these devices operate from a single 2.5V to 11V supply (or ±1.25V to ±5.5V dual supplies), and each comparator’s input voltage ranges from the negative supply rail to within 1.3V of the positive supply. ♦ Available in Ultra-Small Packages: UCSP™ (MAX972) µMAX (MAX9_1/MAX9_2/MAX9_3) ♦ Ultra-Low Quiescent Current (4µA, max) Over Extended Temp Range (MAX971/MAX981) ♦ Power Supplies: Single 2.5V to 11V Dual ±1.25V to ±5.5V ♦ Input Voltage Range Includes Negative Supply ♦ Internal Bandgap Reference 1.182V ±1% (MAX97_) 1.182V ±2% (MAX98_) ♦ 12µs Propagation Delay (10mV Overdrive) ♦ Output Has Separate GND Pin (MAX9_1/MAX9_4) Applications Battery-Powered Systems Window Comparators Threshold Detectors Oscillator Circuits Level Translators Ordering Information PART TEMP RANGE 0°C to +70°C 8 SO MAX971CUA 0°C to +70°C 8 µMAX 1% 1 Yes 8-Pin DIP/SO/µMAX MAX972 None 2 No 8-Pin UCSP/ DIP/SO/µMAX 3 IN+ MAX973 1% 2 Yes 8-Pin DIP/SO/µMAX 4 IN- PACKAGE INTERNAL HYSTERESIS MAX971CSA COMPARATORS PER PACKAGE 8 Plastic Dip INTERNAL PRECISION REFERENCE 0°C to +70°C MAX971 MAX974 1% 4 No 16-Pin DIP/SO MAX981 2% 1 Yes 8-Pin DIP/SO/µMAX MAX982 2% 2 Yes 8-Pin DIP/SO/µMAX MAX983 2% 2 Yes 8-Pin DIP/SO/µMAX MAX984 2% 4 No 16-Pin DIP/SO PIN-PACKAGE MAX971CPA PART The single MAX971/MAX981 and the dual MAX973/ MAX982/MAX983 provide a unique, simple method for adding hysteresis without feedback or complicated equations, simply by using the HYST pin plus two resistors. The MAX971–MAX974 and MAX981–MAX984’s opendrain outputs permit wire-ORed configurations. Thanks to an 11V output range and separate GND pin for the output transistor (MAX971/MAX974, MAX981/MAX984), these devices are ideal for level translators and bipolar to singleended converters. For similar devices with complementary output stages, see the MAX921–MAX924 (1% reference) and the MAX931–MAX934 (2% reference). Features Ordering Information continued at end of data sheet. Typical Operating Circuit VIN 7 V+ OUT 8 5 HYST MAX971 MAX981 6 REF V2 GND 1 THRESHOLD DETECTOR UCSP is a trademark of Maxim Integrated Products, Inc. ________________________________________________________________________________________ 1 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. MAX971–MAX974/MAX981–MAX984 General Description MAX971–MAX974/MAX981–MAX984 Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators ABSOLUTE MAXIMUM RATINGS V+ to V-, V+ to GND, GND to V-................................-0.3V, +12V Inputs Current: IN_+, IN_-, HYST..............................................20mA Voltage: IN_+, IN_-, HYST ...............(V+ + 0.3V) to (V- - 0.3V) Outputs Current: REF...................................................................20mA OUT_ ................................................................50mA Voltage: REF ....................................(V+ + 0.3V) to (V- - 0.3V) OUT_ (MAX9_1/9_4)..................12V to (GND - 0.3V) (MAX9_2/9_3).......................12V to (V- - 0.3V) OUT_ Short-Circuit Duration ..................................Continuous Continuous Power Dissipation (TA = +70°C) 8-Bump UCSP (derate 4.7mW/°C above +70°C) ........379mW 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 µMAX (derate 4.1mW/°C above +70°C) .............330mW 16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)..842mW 16-Pin SO (derate 8.70mW/°C above +70°C) ................696mW Operating Temperature Ranges MAX97_C_ _/MAX98_C_ _ ..................................0°C to +70°C MAX97_E_ _/MAX98_E_ _ ...............................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C Bump Temperature (soldering) Reflow ..........................................................................+235°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—5V OPERATION (V+ = 5V, V- = GND = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER CONDITIONS MIN TYP MAX UNITS POWER REQUIREMENTS Supply Voltage Range (Note 2) Output Voltage Range MAX9_1, HYST = REF Supply Current IN+ = IN- + 100mV 11 V 0 11 V TA = +25°C 2.5 3.2 2.5 3.2 C/E temp ranges 4 TA = +25°C MAX972 C/E temp ranges MAX982/ MAX9_3, HYST = REF MAX9_4 2.5 4 TA = +25°C 3.1 C/E temp ranges 4.5 µA 6 TA = +25°C 5.5 C/E temp ranges 6.5 8.5 COMPARATOR Input Offset Voltage VCM = 2.5V Input Leakage Current (IN-, IN+) IN+ = IN- = 2.5V Input Leakage Current (HYST) MAX9_1/MAX982/MAX9_3 C/E temp ranges ±0.01 ±10 mV ±5 nA ±0.02 Input Common-Mode Voltage Range V- nA V+ - 1.3 V Common-Mode Rejection Ratio V- to (V+ - 1.3V) 0.1 1.0 mV/V Power-Supply Rejection Ratio V+ = 2.5V to 11V 0.1 1.0 mV/V Voltage Noise 100Hz to 100kHz Hysteresis Input Voltage Range MAX9_1/MAX982/MAX9_3 Response Time (High-to-Low Transition) TA = +25°C, 100pF load, 1MΩ pullup to V+ Response Time (Low-to-High Transition) (Note 3) TA = +25°C, 100pF load, 1MΩ pullup to V+ 2 20 REF - 0.05 µVRMS REF Overdrive = 10mV 12 Overdrive = 100mV 4 300 _______________________________________________________________________________________ V µs µs Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators (V+ = 5V, V- = GND = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Output Low Voltage Output Leakage Current CONDITIONS MIN TYP MAX UNITS MAX9_2/MAX9_3, IOUT = 1.8mA V- + 0.4 MAX9_1/MAX9_4, IOUT = 1.8mA GND + 0.4 V 100 nA VOUT = 11V REFERENCE (MAX9_1/MAX982/MAX9_3/MAX9_4 ONLY) MAX971/MAX973/ MAX974 Reference Voltage MAX981–MAX984 Source Current Sink Current Voltage Noise C temp range 1% 1.170 E temp range 2% 1.158 C temp range 2% 1.158 E temp range 3% 1.147 TA = +25°C 15 C/E temp ranges 6 TA = +25°C 8 C/E temp ranges 4 100Hz to 100kHz 1.182 1.194 1.206 1.182 1.206 V 1.217 25 µA 15 µA 100 µVRMS ELECTRICAL CHARACTERISTICS—3V OPERATION (V+ = 3V, V- = GND = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER CONDITIONS MIN TYP MAX 2.4 3.0 UNITS POWER REQUIREMENTS MAX9_1 HYST = REF, IN+ = (IN- + 100mV) Supply Current MAX972 MAX982/ MAX9_3 MAX9_4 TA = +25°C C/E temp ranges 3.8 TA = +25°C 2.4 3.0 3.4 4.3 5.2 6.2 C/E temp ranges 3.8 TA = +25°C C/E temp ranges µA 5.8 TA = +25°C C/E temp ranges 8.0 COMPARATOR Input Offset Voltage VCM = 1.5V Input Leakage Current (IN-, IN+) IN+ = IN- = 1.5V Input Leakage Current (HYST) Input Common-Mode Voltage Range Common-Mode Rejection Ratio MAX9_1/MAX982/MAX9_3 V- to (V+ - 1.3V) Power-Supply Rejection Ratio Voltage Noise Hysteresis Input Voltage Range MAX9_1/MAX982/MAX9_3 C/E temp ranges ±0.01 ±10 mV ±5 nA ±0.02 V- nA V+ - 1.3 V 0.2 1 mV/V V+ = 2.5V to 11V 0.1 1 100Hz to 100kHz 20 REF - 0.05 mV/V µVRMS REF V _______________________________________________________________________________________ 3 MAX971–MAX974/MAX981–MAX984 ELECTRICAL CHARACTERISTICS—5V OPERATION (continued) MAX971–MAX974/MAX981–MAX984 Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators ELECTRICAL CHARACTERISTICS—3V OPERATION (continued) (V+ = 3V, V- = GND = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER CONDITIONS MIN 12 Overdrive = 100mV 4 Response Time (High-to-Low Transition) TA = +25°C, 100pF load, 1MΩ pullup to V+ Response Time (Low-to-High Transition) (Note 3) TA = +25°C, 100pF load, 1MΩ pullup to V+ Output Low Voltage Output Leakage Current TYP Overdrive = 10mV MAX UNITS µs 300 µs MAX9_2/MAX9_3, IOUT = 0.8mA V- + 0.4 MAX9_1/MAX9_4, IOUT = 0.8mA GND + 0.4 VOUT = 11V 100 V nA REFERENCE MAX971/MAX973/ MAX974 Reference Voltage MAX981–MAX984 Source Current Sink Current Voltage Noise C temp range 1% 1.170 E temp range 2% 1.158 C temp range 2% 1.158 E temp range 3% 1.147 TA = +25°C 15 C/E temp ranges 6 TA = +25°C 8 C/E temp ranges 4 100Hz to 100kHz 1.182 1.194 1.206 1.182 1.206 V 1.217 25 15 100 µA µA µVRMS Note 1: The MAX972EBL is 100% tested at TA = +25°C. Temperature limits are guaranteed by design. Note 2: MAX974/MAX984 comparators work below 2.5V; see Low-Voltage Operation section for more details. Note 3: Low-to-high response time is the result of the 1MΩ pullup and the 100pF capacitive load, based on three time constants. A faster response time is achieved with a smaller RC. 4 _______________________________________________________________________________________ Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators REFERENCE OUTPUT VOLTAGE vs. OUTPUT LOAD CURRENT 1.0 0.5 1.180 SOURCE 1.175 1.170 1.165 V+ = 5V OR V+ = 3V 1.160 4 8 16 12 1.17 1.16 1.15 10 5 20 15 25 30 -60 -40 -20 0 20 40 60 80 100 120 140 MAX9_1 SUPPLY CURRENT vs. TEMPERATURE MAX972 SUPPLY CURRENT vs. TEMPERATURE MAX982/MAX9_3 SUPPLY CURRENT vs. TEMPERATURE 3.0 V+ = 3V, V- = 0V 4.0 3.5 V+ = 10V, V- = 0V 3.0 2.5 V+ = 5V, V- = 0V 5.0 4.5 2.0 V+ = 5V, V- = 0V 3.5 3.0 2.5 V+ = 3V, V- = 0V 1.5 2.0 20 4.0 V+ = 3V, V- = 0V V+ = 5V, V- = 0V -20 MAX971-4/981-4 TOC6 IN+ = (IN- + 100mV) SUPPLY CURRENT (µA) MAX971-4/981-4 TOC4 V+ = 5V, V- = - 5V 4.5 2.5 60 100 2.0 -60 140 -20 20 100 60 140 -60 -20 20 60 100 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) MAX9_4 SUPPLY CURRENT vs. TEMPERATURE MAX9_4 SUPPLY CURRENT vs. LOW SUPPLY VOLTAGES MAX9_1/MAX982/MAX9_3 HYSTERESIS CONTROL V+ = 5V, V- = -5V 6 V+ = 5V, V- = 0V 5 4 1 0.1 20 60 TEMPERATURE (°C) 20 0 NO CHANGE -20 OUTPUT LOW -60 3 -20 OUTPUT HIGH 40 -40 V+ = 3V, V- = 0V -60 60 140 MAX971-4/981-4 TOC9 8 80 IN+ - IN- (V) 9 10 MAX971-4/981-4 TOC8 IN+ = (IN- + 100mV) SUPPLY CURRENT (µA) MAX971-4/981-4 TOC7 10 SUPPLY CURRENT (µA) 1.18 TEMPERATURE (°C) 4.0 -60 COMMERCIAL TEMP RANGE 1.19 OUTPUT LOAD CURRENT (µA) IN+ = IN- + 100mV 3.5 EXTENDED TEMP RANGE 1.20 LOAD CURRENT (mA) 4.5 7 1.21 1.14 0 20 SUPPLY CURRENT (µA) 0 MAX971-4/981-4 TOC3 1.185 1.22 1.155 0 SUPPLY CURRENT (µA) SINK MAX971-4/981-4 TOC5 VOL (V) V+ = 3V 1.5 1.190 REFERENCE VOLTAGE (V) 2.0 MAX971/MAX973/MAX974 REFERENCE VOLTAGE vs. TEMPERATURE MAX971-4/981-4 TOC2 V+ = 5V REFERENCE OUTPUT VOLTAGE (V) 2.5 MAX971-4/981-4-TOC1 OUTPUT VOLTAGE LOW vs. LOAD CURRENT 100 140 -80 0.01 1.0 1.5 2.0 SINGLE-SUPPLY VOLTAGE (V) 2.5 0 10 20 30 40 50 VREF - VHYST (mV) _______________________________________________________________________________________ 5 MAX971–MAX974/MAX981–MAX984 __________________________________________Typical Operating Characteristics (V+ = 5V, V- = GND = 0V, TA = +25°C, unless otherwise noted.) Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators Typical Operating Characteristics (continued) (V+ = 5V, V- = GND = 0V, TA = +25°C, unless otherwise noted.) 3.0 2.5 2.0 1.5 1.0 14 VOHL 12 0 5 4 10mV 3 100mV 2 10 1 8 0 6 4 0.5 20mV 50mV 100 0 2 0.3 0 RESPONSE TIME AT LOW SUPPLY VOLTAGES (VOHL) 100 -20mV 10 40 60 80 100 -2 2 6 10 14 LOAD CAPACITANCE (nF) RESPONSE TIME (µs) MAX9_4 SINK CURRENT AT LOW SUPPLY VOLTAGES SHORT-CIRCUIT SINK CURRENT vs. SUPPLY VOLTAGE MAX971-4/981-4 TOC14 100 CURRENT (mA) RPULLUP = 10kΩ MAX971-4/981-4 TOC13 1000 20 10 1 25 OUT CONNECTED TO V+ GND CONNECTED TO V20 18 MAX971-4/981-4 TOC15 0.2 0.1 -0.2 -0.1 0 IN+ INPUT VOLTAGE (mV) SINK CURRENT (mA) -0.3 RESPONSE TIME (µs) MAX971-4/981-4 TOC11 10µF 3.5 V- = 0V 16 VOUT (V) V0 VIN (mV) 100kΩ RESPONSE TIME FOR VARIOUS INPUT OVERDRIVES (VOHL) 18 RESPONSE TIME (µs) +5V 10kΩ 4.0 OUTPUT VOLTAGE (V) MAX971-4/981-4 TOC10 5.0 4.5 RESPONSE TIME vs. LOAD CAPACITANCE MAX971-4/981-4 TOC12 MAX9_1/MAX972/MAX9_4 TRANSFER FUNCTION 15 10 5 -100mV SINK CURRENT AT VOUT = 0.4V 1 0.1 1.0 1.2 1.4 1.6 1.8 2.0 2.2 SINGLE-SUPPLY VOLTAGE (V) 6 2.4 1.0 1.5 2.0 SINGLE-SUPPLY VOLTAGE (V) 2.5 0 5 0 TOTAL SUPPLY VOLTAGE (V) _______________________________________________________________________________________ 10 Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators PIN MAX971/ MAX981 MAX972 MAX982 MAX973/ MAX983 NAME FUNCTION DIP/SO/ µMAX DIP/SO/ µMAX UCSP DIP/SO/ µMAX DIP/SO/ µMAX 1 — — — — GND Ground. Connect to V- for single-supply operation. 2 2 C2 2 2 V- Negative Supply. Connect to GND for single-supply operation (MAX9_1). 3 — — — — IN+ Noninverting Comparator Input 4 — — — — IN- Inverting Comparator Input 5 — — 5 5 HYST 6 — — 6 6 REF Reference Output. 1.182V with respect to V-. 7 7 A2 7 7 V+ Positive Supply 8 — — — — OUT — 1 A1 1 1 OUTA — 3 C1 3 3 INA+ Noninverting Input of Comparator A — 4 B1 — — INA- Inverting Input of Comparator A — 5 B3 — 4 INB- Inverting Input of Comparator B — 6 C3 4 — INB+ Noninverting Input of Comparator B — 8 A3 8 8 OUTB Comparator B Open-Drain Output. Sinks current to V-. Hysteresis Input. Connect to REF if not used. Input voltage range is from VREF to (VREF - 50mV). Comparator Output. Sinks current to GND. Comparator A Open-Drain Output. Sinks current to V-. _______________________________________________________________________________________ 7 MAX971–MAX974/MAX981–MAX984 Pin Description Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators MAX971–MAX974/MAX981–MAX984 Pin Description (continued) PIN MAX974 MAX984 8 NAME FUNCTION 1 OUTB Comparator B Open-Drain Output. Sinks current to GND. 2 OUTA Comparator A Open-Drain Output. Sinks current to GND. 3 V+ 4 INA- Inverting Input of Comparator A 5 INA+ Noninverting Input of Comparator A 6 INB- Inverting Input of Comparator B 7 INB+ Noninverting Input of Comparator B 8 REF Reference Output. 1.182V with respect to V-. 9 V- 10 INC- Inverting Input of Comparator C 11 INC+ Noninverting Input of Comparator C 12 IND- Inverting Input of Comparator D 13 IND+ Noninverting Input of Comparator D 14 GND Ground. Connect to V- for single-supply operation. 15 OUTD Comparator D Open-Drain Output. Sinks current to GND. 16 OUTC Comparator C Open-Drain Output. Sinks current to GND. Positive Supply Negative Supply. Connect to ground for single-supply operation. _______________________________________________________________________________________ Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators Power-Supply and Input Signal Ranges The MAX971–MAX974/MAX981–MAX984 comprise various combinations of a micropower 1.182V reference and micropower comparators. The Typical Operating Circuit shows the MAX971/MAX981 configuration, and Figures 1a–1d show the MAX9_2–MAX9_4 configurations. Internal hysteresis in the MAX9_1, MAX982, and MAX9_3 provides the easiest method for implementing hysteresis. It also produces faster hysteresis action and consumes much less current than circuits using external positive feedback. This family of devices operates from a single 2.5V to 11V power supply. The MAX9_1 and MAX9_4 have a separate ground for the output driver, allowing operation with dual supplies ranging from ±1.25V to ±5.5V. Connect V- to GND when operating the MAX9_1 or MAX9_4 from a single supply. The maximum total supply voltage in this case is still 11V. MAX972 1 (A1) OUTA 2 (C2) V- OUTB 8 (A3) V+ 7 (A2) 3 (C1) INA+ INB+ 6 (C3) 4 (B1) INA- INB- 5 (B3) For proper comparator operation, the input signal can range from the negative supply (V-) to within one volt of the positive supply (V+ - 1V). The guaranteed commonmode input voltage range extends from V- to (V+ 1.3V). The inputs can be taken above and below the supply rails by up to 300mV without damage. MAX9_3 1 OUTA 2 V- OUTB 8 V+ 7 3 INA+ REF 6 4 INB- HYST 5 V- Figure 1c. MAX973/MAX983 Functional Diagram (Window Comparator) ( ) BUMPS FOR THE UCSP Figure 1a. MAX972 Functional Diagram 1 OUTB 2 OUTA MAX982 1 OUTA 2 V- MAX9_4 OUTC 16 OUTD 15 3 V+ GND 14 4 INA- IND+ 13 5 INA+ IND- 12 6 INB- INC+ 11 7 INB+ INC- 10 8 REF V- 9 OUTB 8 V+ 7 3 INA+ REF 6 4 INB+ HYST 5 V- Figure 1b. MAX982 Functional Diagram Figure 1d. MAX974/MAX984 Functional Diagram _______________________________________________________________________________________ 9 MAX971–MAX974/MAX981–MAX984 Detailed Description MAX971–MAX974/MAX981–MAX984 Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators THRESHOLDS IN+ INVREF - VHYST HYSTERESIS VHB The negative supply does not affect the output sink current. The positive supply provides gate drive for the output N-channel MOSFET and heavily influences the output current capability, especially at low supply voltages (see Typical Operating Characteristics section). The MAX9_2 and MAX9_3 have no GND pin, and their outputs sink current to V-. BAND Voltage Reference The internal bandgap voltage reference has an output of 1.182V above V-. Note that the REF voltage is referenced to V-, not to GND. Its accuracy is ±1% (MAX971/MAX973/MAX974) or ±2% (MAX981–MAX984) in the 0°C to +70°C range. The REF output is typically capable of sourcing 25µA and sinking 15µA. Do not bypass the REF output. OUT Noise Considerations Figure 2. Threshold Hysteresis Band Low-Voltage Operation: V+ = 1V (MAX9_4 Only) The guaranteed minimum operating voltage is 2.5V (or ±1.25V). As the total supply voltage falls below 2.5V, performance degrades and the supply current falls. The reference will not function below about 2.2V, although the comparators will continue to operate with a total supply voltage as low as 1V. While the MAX9_4 has comparators that may be used at supply voltages below 2V, the MAX9_1/MAX9_2/MAX9_3 may not be used with supply voltages below 2.5V. At low supply voltages, the comparators’ output sink capability is reduced and the propagation delay increases (see Typical Operating Characteristics). The useful input voltage range extends from the negative supply to a little under 1V below the positive supply, which is slightly closer to the positive rail than when the device operates from higher supply voltages. Test your prototype over the full temperature and supply-voltage range if you anticipate operation below 2.5V. Although the comparators have a very high gain, useful gain is limited by noise. This is shown in the Transfer Function graph (see Typical Operating Characteristics). As the input voltage approaches the comparator’s offset, the output begins to bounce back and forth; this peaks when VIN = VOS. (The lowpass filter shown on the graph averages out the bouncing, making the transfer function easy to observe.) Consequently, the comparator has an effective wideband peak-to-peak noise of around 300µV. The voltage reference has peak-to-peak noise approaching 1mV. Thus, when a comparator is used with the reference, the combined peak-to-peak noise is about 1mV. This, of course, is much higher than the RMS noise of the individual components. Take care in your layout to avoid capacitive coupling from any output to the reference pin. Crosstalk can significantly increase the actual noise of the reference. IREF Comparator Output With 100mV of overdrive, propagation delay is typically 3µs. The Typical Operating Characteristics show the propagation delay for various overdrive levels. The open-drain outputs are intended for wire-ORed and level-shifting applications. The maximum output voltage is 11V above V-, and may be applied even when no supply voltage is present (V+ = V-). The MAX9_1 and MAX9_4 outputs sink current to GND, making these devices ideal for bipolar to single-ended conversion and level-shifting applications. 10 6 REF 2.5V TO 11V 7 V+ MAX9_1 MAX982 MAX9_3 R1 5 R2 HYST V2 Figure 3. Programming the HYST Pin ______________________________________________________________________________________ Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators V+ Hysteresis RH Hysteresis increases the comparators’ noise margin by increasing the upper threshold and decreasing the lower threshold (Figure 2). Hysteresis (MAX9_1/MAX982/MAX9_3) To add hysteresis to the MAX9_1, MAX982, or MAX9_3, connect resistor R1 between REF and HYST, and connect resistor R2 between HYST and V- (Figure 3). If no hysteresis is required, connect HYST to REF. When hysteresis is added, the upper threshold increases by the same amount that the lower threshold decreases. The hysteresis band (the difference between the upper and lower thresholds, VHB) is approximately equal to twice the voltage between REF and HYST. The HYST input can be adjusted to a maximum voltage of REF and to a minimum voltage of (REF - 50mV). The maximum difference between REF and HYST (50mV) will therefore produce a 100mV (max) hysteresis band. Use the following equations to determine R1 and R2: VHB R1 = 2 × IREF ( ) VHB 1.182 – 2 R2 = IREF where I REF (the current sourced by the reference) should not exceed the REF source capability, and should be significantly larger than the HYST input current. IREF values between 0.1µA and 4µA are usually appropriate. If 2.4MΩ is chosen for R2 (IREF = 0.5µA), the equation for R1 and VHB can be approximated as: R1 (kΩ) = VHB (mV) When hysteresis is obtained in this manner for the MAX982/MAX9_3, the same hysteresis applies to both comparators. Hysteresis (MAX972/MAX9_4) Hysteresis can be implemented with any comparator using positive feedback, as shown in Figure 4. This approach generally draws more current than circuits using the HYST pin on the MAX9_1/MAX982/MAX9_3, and the high feedback impedance slows hysteresis. In addition, because the output does not source current, any increase in the upper threshold is dependent on the load or pullup resistor on the output. RPULLUP VIN V+ MAX9_4 V- OUT GND VREF Figure 4. External Hysteresis Board Layout and Bypassing Power-supply bypass capacitors are not needed if the supply impedance is low, but 100nF bypass capacitors should be used when the supply impedance is high or when the supply leads are long. Minimize signal lead lengths to reduce stray capacitance between the input and output that might cause instability. Do not bypass the reference output. Window Detector The MAX9_3 is ideal for making window detectors (undervoltage/overvoltage detectors). The schematic is shown in Figure 5, with component values selected for a 4.5V undervoltage threshold and a 5.5V overvoltage threshold. Choose different thresholds by changing the values of R1, R2, and R3. To prevent chatter at the output when the supply voltage is close to a threshold, hysteresis has been added using R4 and R5. Taken alone, OUTA would provide an active-low undervoltage indication, and OUTB would give an active-low overvoltage indication. Wired-ORing the two outputs provides an active-high, power-good signal. The design procedure is as follows: 1) Choose the required hysteresis level and calculate values for R4 and R5 according to the formulas in the Hysteresis (MAX9_1/MAX982/MAX9_3) section. In this example, ±5mV of hysteresis has been added at the comparator input (VH = VHB/2). This means that the hysteresis apparent at V IN will be larger because of the input resistor divider. ______________________________________________________________________________________ 11 MAX971–MAX974/MAX981–MAX984 __________Applications Information MAX971–MAX974/MAX981–MAX984 Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators 2) Select R1. The leakage current into INB- is normally under 1nA, so the current through R1 should exceed 100nA for the thresholds to be accurate. R1 values up to about 10MΩ can be used, but values in the 100kΩ to 1MΩ range are usually easier to deal with. In this example, choose R1 = 294kΩ. VIN VOTH = 5.5V VUTH = 4.5V R3 1MΩ 3) Calculate R2 + R3. The overvoltage threshold should be 5.5V when V IN is rising. The design equation is as follows: VOTH R2 + R3 = R1 × − 1 VREF + VH 5V 7 V+ 3 INA+ OUTA 1 5 HYST 5.5 = 294kΩ × − 1 (1.182 + 0.005) R2 62.2kΩ R5 10kΩ R4 2.4MΩ 6 REF = 1.068MΩ OUTB 8 4) Calculate R2. The undervoltage threshold should be 4.5V when VIN is falling. The design equation is as follows: R2 = (R1 + R2 + R 3) × 4 INBR1 294kΩ POWER GOOD V- MAX9_3 2 (VREF − VH ) − R1 VUTH = (294kΩ + 1.068MΩ) × (1.182 − 0.005) 4.5 Figure 5. Window Detector − 294kΩ = 62.2kΩ Battery Switchover Circuit Choose R2 = 61.9kΩ (1% s tan dard value). 5) Calculate R3: R3 = (R2 + R3 ) − R2 = 1.068MΩ − 61.9 kΩ = 1.006MΩ Choose R3 = 1MΩ (1% standard value) 6) Verify the resistor values. The equations are as follows, evaluated for the above example: Overvoltage Threshold: (R1 + R2 + R3) VOTH = (VREF + VH ) × R1 = 5.474V Undervoltage Threshold : (R1 + R2 + R3) VUTH = (VREF − VH ) × (R1 + R2) The switchover from line-powered DC to a backup battery is often accomplished with diodes. But this simple method is sometimes unacceptable, due to the voltage drop and associated power loss across the diode in series with the battery. Figure 6’s circuit replaces the diode with a P-channel MOSFET controlled by one of the MAX9_3 comparator outputs. When the DC wall adapter drops below 4V (determined by R1 and R2), OUTA goes low, turning on Q1. Comparator B is used to measure the battery voltage, and gives a “low-battery” indication when the battery drops below 3.6V. Level-Shifter Figure 7 shows a circuit to shift from bipolar ±5V inputs to single-ended 5V outputs. The 10kΩ resistors protect the comparator inputs, and do not materially affect the circuit’s operation. = 4.484V where the hysteresis voltage VH = VREF × 12 1MΩ R5 . R4 ______________________________________________________________________________________ Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators 3.3V 3 WALL ADAPTER V+ 9V DC 10kΩ STEP-DOWN REGULATOR 3.3V LOGIC SUPPLY Q1 5 INA+ VINA MAX974 MAX984 OUTA 2 4 INA- 1MΩ 10kΩ 7 V+ BATTERY (4 CELLS) 7 INB+ VINB OUTB 1 MAX973 MAX983 953kΩ 10kΩ 6 INB- 4 INB- 10kΩ OUTB 8 470kΩ VINC 11 INC+ LOW BATT OUTC 16 1 OUTA R1 110kΩ 10 INC- DC OK 10kΩ VIND 3 INA+ 13 IND+ OUTD 15 REF 6 20kΩ R2 47kΩ 12 INDREF HYST 5 V2 2.4MΩ GND 14 8 N.C. V9 -5V Figure 6. Battery Switchover Circuit Figure 7. Level Shifter: ±5V Input to Single-Ended 3.3V Output UCSP Applications Information For the latest application details on UCSP contruction, dimensions, tape carrier information, printed circuit board techniques, bump-pad layout and recommended reflow temperature profile as well as the latest information on reliability testing results, go to Maxim’s web site at www.maxim-ic.com/ucsp to find the Application Note: UCSP–A Wafer-Level Chip-Scale Package. ______________________________________________________________________________________ 13 MAX971–MAX974/MAX981–MAX984 5V Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators MAX971–MAX974/MAX981–MAX984 Pin Configurations TOP VIEW GND 1 V- 2 MAX971 MAX981 IN+ 3 IN- 4 8 OUT 7 V+ 6 REF INA+ 3 5 HYST INA- 4 OUTA 1 V- 2 DIP/SO/µMAX MAX972 8 OUTB 7 V+ 6 INB+ INA+ 3 5 INB- INB+ 4 OUTA 1 V- 2 MAX982 8 OUTB 7 V+ 6 REF 5 HYST DIP/SO/µMAX DIP/SO/µMAX TOP VIEW (BUMPS ON BOTTOM) A 1 2 3 OUTA V+ OUTB OUTA 1 V- 2 B INA- MAX972 INB- INA+ 3 MAX973 MAX983 INB- 4 C INA+ V- UCSP INB+ 8 OUTB OUTB 1 16 OUTC 7 V+ OUTA 2 15 OUTD 6 REF 5 HYST V+ 3 INA- 4 INA+ 5 DIP/SO/µMAX 14 GND MAX974 MAX984 12 IND- INB- 6 11 INC+ INB+ 7 10 INC- REF 8 9 DIP/Narrow SO 14 13 IND+ ______________________________________________________________________________________ V- Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators PART PART TEMP RANGE PIN-PACKAGE TEMP RANGE PIN-PACKAGE MAX971EPA -40°C to +85°C 8 Plastic Dip MAX981CSA MAX971ESA -40°C to +85°C 8 SO MAX981CUA 0°C to +70°C MAX972CPA 0°C to +70°C 8 Plastic Dip MAX981EPA -40°C to +85°C 8 Plastic Dip MAX972CSA 0°C to +70°C 8 SO MAX981ESA -40°C to +85°C 8 SO 8 µMAX MAX982CPA 0°C to +70°C 8 Plastic Dip 8 SO MAX972CUA 0°C to +70°C 0°C to +70°C 8 SO 8 µMAX MAX972EBL-T* -40°C to +85°C 8 UCSP-8 MAX982CSA 0°C to +70°C MAX972EPA -40°C to +85°C 8 Plastic Dip MAX982CUA 0°C to +70°C -40°C to +85°C 8 Plastic Dip 8 SO 8 µMAX MAX972ESA -40°C to +85°C 8 SO MAX982EPA MAX973CPA 0°C to +70°C 8 Plastic Dip MAX982ESA -40°C to +85°C MAX973CSA 0°C to +70°C 8 SO MAX983CPA 0°C to +70°C 8 Plastic Dip MAX973CUA 0°C to +70°C 8 µMAX MAX983CSA 0°C to +70°C 8 SO MAX973EPA -40°C to +85°C 8 Plastic Dip MAX983CUA 0°C to +70°C MAX973ESA -40°C to +85°C 8 SO MAX983EPA -40°C to +85°C 8 Plastic Dip MAX974CPE 0°C to +70°C 16 Plastic Dip MAX983ESA -40°C to +85°C 8 SO 8 µMAX MAX974CSE 0°C to +70°C 16 Narrow SO MAX984CPE 0°C to +70°C 16 Plastic Dip MAX974EPE -40°C to +85°C 16 Plastic Dip MAX984CSE 0°C to +70°C 16 Narrow SO MAX974ESE -40°C to +85°C 16 Narrow SO MAX984EPE -40°C to +85°C 16 Plastic Dip MAX981CPA 0°C to +70°C 8 Plastic Dip MAX984ESE -40°C to +85°C 16 Narrow SO *UCSP top mark is “ABC.” ___________________Chip Information MAX971/MAX972/MAX973/MAX981/MAX982/MAX984 TRANSISTOR COUNT: 164 MAX974/MAX984 TRANSISTOR COUNT: 267 ______________________________________________________________________________________ 15 MAX971–MAX974/MAX981–MAX984 Ordering Information (continued) Package Information 4X S 8 8 E ÿ 0.50±0.1 H MIN 0.002 0.030 0.6±0.1 L 1 α 0.6±0.1 S BOTTOM VIEW D MAX 0.043 0.006 0.037 0.05 0.75 1.10 0.15 0.95 0.25 0.36 0.13 0.18 2.95 3.05 0.65 BSC 2.95 3.05 4.78 5.03 0.41 0.66 0∞ 6∞ 0.5250 BSC 0.010 0.014 0.005 0.007 0.116 0.120 0.0256 BSC 0.116 0.120 0.188 0.198 0.016 0.026 6∞ 0∞ 0.0207 BSC c D e E H 1 MILLIMETERS MAX MIN INCHES DIM A A1 A2 b 8LUMAXD.EPS (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) TOP VIEW A1 A2 A α c e L b SIDE VIEW FRONT VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, 8L uMAX/uSOP APPROVAL DOCUMENT CONTROL NO. 21-0036 DIM A A1 B C e E H L N E H INCHES MILLIMETERS MAX MIN 0.069 0.053 0.010 0.004 0.014 0.019 0.007 0.010 0.050 BSC 0.150 0.157 0.228 0.244 0.016 0.050 MAX MIN 1.35 1.75 0.10 0.25 0.35 0.49 0.19 0.25 1.27 BSC 3.80 4.00 5.80 6.20 0.40 REV. 1 J 1 SOICN .EPS MAX971–MAX974/MAX981–MAX984 Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators 1.27 VARIATIONS: 1 INCHES TOP VIEW DIM D D D MIN 0.189 0.337 0.386 MAX 0.197 0.344 0.394 MILLIMETERS MIN 4.80 8.55 9.80 MAX 5.00 8.75 10.00 N MS012 8 AA 14 AB 16 AC D A B e C 0∞-8∞ A1 L FRONT VIEW SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, .150" SOIC APPROVAL DOCUMENT CONTROL NO. 21-0041 16 REV. B 1 1 ______________________________________________________________________________________ Ultra Low-Power, Open-Drain, Single/Dual-Supply Comparators 9LUCSP, 3x3.EPS PDIPN.EPS 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 17 © 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX971–MAX974/MAX981–MAX984 Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.)