19-1862; Rev 2; 8/02 SC70, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Reference Applications Features ♦ Space-Saving SC70 Package (Half the Size of SOT23) ♦ Ultra-Low Supply Current 350nA Per Comparator (MAX9119/MAX9120) 600nA Per Comparator with Reference (MAX9117/MAX9118) ♦ Guaranteed to Operate Down to +1.8V ♦ Internal 1.252V ±1.75% Reference (MAX9117/MAX9118) ♦ Input Voltage Range Extends 200mV Beyond-the-Rails ♦ CMOS Push-Pull Output with ±5mA Drive Capability (MAX9117/MAX9119) ♦ Open-Drain Output Versions Available (MAX9118/MAX9120) ♦ Crowbar-Current-Free Switching ♦ Internal Hysteresis for Clean Switching ♦ No Phase Reversal for Overdriven Inputs 2-Cell Battery Monitoring/Management Ultra-Low-Power Systems Ordering Information Mobile Communications Notebooks and PDAs Threshold Detectors/Discriminators PART TEMP RANGE PINPACKAGE TOP MARK MAX9117EXK-T -40°C to +85°C 5 SC70-5 ABW MAX9118EXK-T -40°C to +85°C 5 SC70-5 ABX Sensing at Ground or Supply Line MAX9119EXK-T -40°C to +85°C 5 SC70-5 ABY Telemetry and Remote Systems MAX9120EXK-T -40°C to +85°C 5 SC70-5 ABZ Medical Instruments Selector Guide PART INTERNAL REFERENCE OUTPUT TYPE SUPPLY CURRENT (nA) MAX9117 Yes Push-Pull 600 MAX9118 Yes Open-Drain 600 MAX9119 No Push-Pull 350 MAX9120 No Open-Drain 350 Typical Application Circuit appears at end of data sheet. Pin Configurations TOP VIEW OUT 1 VEE 2 Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd. VCC 4 IN- (REF) MAX9117 MAX9118 MAX9119 MAX9120 IN+ 3 Beyond-the-Rails is a trademark of Maxim Integrated Products, Inc. 5 SC70 ( ) ARE FOR MAX9117/MAX9118. ________________________________________________________________ Maxim Integrated Products 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. 1 MAX9117–MAX9120 General Description The MAX9117–MAX9120 nanopower comparators in space-saving SC70 packages feature Beyond-theRails™ inputs and are guaranteed to operate down to +1.8V. The MAX9117/MAX9118 feature an on-board 1.252V ±1.75% reference and draw an ultra-low supply current of only 600nA, while the MAX9119/MAX9120 (without reference) require just 350nA of supply current. These features make the MAX9117–MAX9120 family of comparators ideal for all 2-cell battery-monitoring/management applications. The unique design of the output stage limits supply-current surges while switching, virtually eliminating the supply glitches typical of many other comparators. This design also minimizes overall power consumption under dynamic conditions. The MAX9117/MAX9119 have a push-pull output stage that sinks and sources current. Large internal-output drivers allow Rail-to-Rail® output swing with loads up to 5mA. The MAX9118/MAX9120 have an open-drain output stage that makes them suitable for mixed-voltage system design. All devices are available in the ultra-small 5-pin SC70 package. MAX9117–MAX9120 SC70, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Reference ABSOLUTE MAXIMUM RATINGS Continuous Power Dissipation (TA = +70°C) 5-Pin SC70 (derate 2.5mW/°C above +70°C) .............200mW 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 Supply Voltage (VCC to VEE)..................................................+6V Voltage Inputs (IN+, IN-, REF) .........(VEE - 0.3V) to (VCC + 0.3V) Output Voltage MAX9117/MAX9119 ....................(VEE - 0.3V) to (VCC + 0.3V) MAX9118/MAX9120 ..................................(VEE - 0.3V) to +6V Current Into Input Pins ........................................................20mA Output Current..................................................................±50mA Output Short-Circuit Duration .................................................10s 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—MAX9117/MAX9118 (VCC = +5V, VEE = 0V, VIN+ = VREF, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Supply Voltage Range SYMBOL VCC CONDITIONS Inferred from the PSRR test MIN VCC = 1.8V Supply Current ICC VCC = 5V Input Offset Voltage VOS (Note 2) Input-Referred Hysteresis VHB (Note 3) Output Voltage Swing High PSRR VCC VOH ILEAK Output Short-Circuit Current MAX9117, VCC = 1.8V, ISOURCE = 1mA TA = +25°C tPD- 0.1 1 400 500 100 200 190 400 TA = TMIN to TMAX TA = +25°C 500 100 TA = TMIN to TMAX mV/V mV 200 mV 1 mA 35 VCC = 1.8V 3 VCC = 5V 35 VCC = 1.8V nA 300 0.002 VCC = 5V mV 300 TA = TMIN to TMAX TA = +25°C V mV 1 190 TA = TMIN to TMAX MAX9118 only, VO = 5.5V ISC 5 10 2 TA = +25°C Sinking, VO = VCC High-to-Low Propagation Delay (Note 4) 1 4 MAX9117, VCC = 5V, ISOURCE = 5mA Sourcing, VO = VEE µA VCC + 0.2 0.15 VCC = 1.8V to 5.5V VCC = 1.8V, ISINK= 1mA Output Leakage Current TA = +25°C VEE 0.2 TA = TMIN to TMAX VOL V 1.30 TA = TMIN to TMAX TA = +25°C VCC = 5V, ISINK= 5mA Output Voltage Swing Low UNITS 5.5 0.68 TA = TMIN to TMAX Inferred from output swing test Power-Supply Rejection Ratio 2 TA = +25°C VIN+ IB MAX 0.60 IN+ Voltage Range Input Bias Current TYP 1.8 mA 3 VCC = 1.8V 16 VCC = 5V 14 _______________________________________________________________________________________ µs SC70, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Reference (VCC = +5V, VEE = 0V, VIN+ = VREF, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MAX9117 only Low-to-High Propagation Delay (Note 4) tPD+ MAX9118 only MIN TYP VCC = 1.8V 15 VCC = 5V 40 VCC = 1.8V, RPULLUP = 100kΩ 16 VCC = 5V, RPULLUP = 100kΩ 45 MAX UNITS µs Rise Time tRISE MAX9117 only, CL = 15pF 1.6 µs Fall Time tFALL CL = 15pF 0.2 µs Power-Up Time tON Reference Voltage VREF Reference Voltage Temperature Coefficient 1.2 TA = +25°C 1.230 TA = TMIN to TMAX 1.196 1.252 ms 1.274 1.308 ppm/ °C 100 TCREF V BW = 10Hz to 100kHz 1.1 BW = 10Hz to 100kHz, CREF = 1nF 0.2 ∆VREF/ ∆VCC VCC = 1.8V to 5.5V 0.25 mV/V ∆VREF/ ∆IOUT ∆IOUT = 10nA ±1 mV/ nA Reference Output Voltage Noise EN Reference Line Regulation Reference Load Regulation mVRMS ELECTRICAL CHARACTERISTICS—MAX9119/MAX9120 (VCC = +5V, VEE = 0V, VCM = 0V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Supply Voltage Range SYMBOL VCC CONDITIONS Inferred from the PSRR test MIN VCC = 1.8V Supply Current ICC VCC = 5V TA = +25°C Inferred from the CMRR test Input Offset Voltage VOS -0.2V ≤ VCM ≤ (VCC + 0.2V) (Note 2) Input Bias Current IB Input Offset Current 0.45 TA = TMIN to TMAX VCM VHB MAX UNITS 5.5 V 0.80 µA 0.35 Input Common-Mode Voltage Range Input-Referred Hysteresis TYP 1.8 TA = +25°C 1.2 VEE 0.2 VCC + 0.2 1 V 5 mV TA = TMIN to TMAX -0.2V ≤ VCM ≤ (VCC + 0.2V) (Note 3) TA = +25°C 10 4 0.15 TA = TMIN to TMAX IOS mV 1 2 75 nA pA Power-Supply Rejection Ratio PSRR VCC = 1.8V to 5.5V 0.1 1 mV/V Common-Mode Rejection Ratio CMRR (VEE - 0.2V) ≤ VCM ≤ (VCC + 0.2V) 0.5 3 mV/V _______________________________________________________________________________________ 3 MAX9117–MAX9120 ELECTRICAL CHARACTERISTICS—MAX9117/MAX9118 (continued) MAX9117–MAX9120 SC70, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Reference ELECTRICAL CHARACTERISTICS—MAX9119/MAX9120 (continued) (VCC = +5V, VEE = 0V, VCM = 0V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Output Voltage Swing High Output Voltage Swing Low Output Leakage Current SYMBOL VCC VOH VOL ILEAK CONDITIONS MAX9119 only, VCC = 5V, ISOURCE = 5mA TA = +25°C MAX9120 only, VCC = 1.8V, ISOURCE = 1mA TA = +25°C VCC = 5V, ISINK = 5mA VCC = 1.8V, ISINK = 1mA ISC Sourcing, VO = VCC High-to-Low Propagation Delay (Note 4) tPDMAX9119 only Low-to-High Propagation Delay (Note 4) tPD+ MAX9120 only TYP MAX 190 400 100 200 TA = TMIN to TMAX 500 TA = TMIN to TMAX TA = +25°C TA = +25°C 190 400 100 200 500 TA = TMIN to TMAX VCC = 5V UNITS mV 300 TA = TMIN to TMAX MAX9120 only, VO = 5.5V Sourcing, VO = VEE Output Short-Circuit Current MIN mV 300 0.001 1 µA 35 VCC = 1.8V 3 VCC = 5V 35 VCC = 1.8V 3 VCC = 1.8V 16 VCC = 5V 14 VCC = 1.8V 15 VCC = 5V 40 VCC = 1.8V, RPULLUP = 100kΩ 16 VCC = 5V, RPULLUP = 100kΩ 45 mA µs µs Rise Time tRISE MAX9119 only, CL = 15pF 1.6 µs Fall Time tFALL CL = 15pF 0.2 µs 1.2 ms Power-Up Time tON Note 1: All specifications are 100% tested at TA = +25°C. Specification limits over temperature (TA = TMIN to TMAX) are guaranteed by design, not production tested. Note 2: VOS is defined as the center of the hysteresis band at the input. Note 3: The hysteresis-related trip points are defined as the edges of the hysteresis band, measured with respect to the center of the band (i.e., VOS) (Figure 2). Note 4: Specified with an input overdrive (VOVERDRIVE) of 100mV, and load capacitance of CL = 15pF. VOVERDRIVE is defined above and beyond the offset voltage and hysteresis of the comparator input. For the MAX9117/MAX9118, reference voltage error should also be added. 4 _______________________________________________________________________________________ SC70, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Reference MAX9119/MAX9120 SUPPLY CURRENT vs. SUPPLY VOLTAGE AND TEMPERATURE 800 750 TA = +25°C 700 650 500 TA = +85°C 450 TA = +25°C 400 350 850 TA = -40°C TA = -40°C 600 900 MAX9117-20 toc02 TA = +85°C 850 550 SUPPLY CURRENT (nA) 250 2.0 2.5 3.0 3.5 4.0 4.5 5.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 -40 -15 10 35 60 85 SUPPLY VOLTAGE (V) TEMPERATURE (°C) MAX9119/MAX9120 SUPPLY CURRENT vs. TEMPERATURE MAX9117/MAX9118 SUPPLY CURRENT vs. OUTPUT TRANSITION FREQUENCY MAX9119/MAX9120 SUPPLY CURRENT vs. OUTPUT TRANSITION FREQUENCY 450 400 350 300 VCC = +1.8V 25 20 VCC = +5V 15 10 VCC = +3V 30 5 VCC = +1.8V 250 10 35 60 VCC = +3V VOL (mV) 300 10 VCC = +3V 10k 100k 1 10 100 1k 10k 100k OUTPUT TRANSITION FREQUENCY (Hz) OUTPUT VOLTAGE LOW vs. SINK CURRENT AND TEMPERATURE MAX9117/MAX9119 OUTPUT VOLTAGE HIGH vs. SOURCE CURRENT 0.7 0.6 0.5 TA = +25°C 400 VCC = +1.8V 1k 500 500 400 100 MAX9117-20 toc08 600 10 600 MAX9117-20 toc07 700 VCC = +5V 15 OUTPUT TRANSITION FREQUENCY (Hz) TEMPERATURE (°C) OUTPUT VOLTAGE LOW vs. SINK CURRENT 20 0 1 85 VCC - VOH (V) -15 VCC = +1.8V 25 5 0 -40 MAX9117-20 toc06 MAX9117-20 toc05 VCC = +3V 30 35 SUPPLY CURRENT (µA) VCC = +5V 35 SUPPLY CURRENT (µA) MAX9117-20 toc04 500 SUPPLY CURRENT (nA) 2.0 SUPPLY VOLTAGE (V) 550 VOL (mV) 650 550 1.5 5.5 VCC = +3V 700 600 550 1.5 750 VCC = +1.8V 300 500 VCC = +5V 800 TA = +85°C 300 MAX9117-20 toc09 SUPPLY CURRENT (nA) 900 SUPPLY CURRENT (nA) MAX9117-20 toc01 950 MAX9117/MAX9118 SUPPLY CURRENT vs. TEMPERATURE MAX9117-20 toc03 MAX9117/MAX9118 SUPPLY CURRENT vs. SUPPLY VOLTAGE AND TEMPERATURE VCC = +3V 0.4 VCC = +1.8V 0.3 200 200 0.2 100 VCC = +5V 100 0 0 0 1 2 3 4 5 6 7 SINK CURRENT (mA) 8 9 10 VCC = +5V 0.1 TA = -40°C 0 0 1 2 3 4 5 6 7 SINK CURRENT (mA) 8 9 10 0 1 2 3 4 5 6 7 8 9 10 SOURCE CURRENT (mA) _______________________________________________________________________________________ 5 MAX9117–MAX9120 Typical Operating Characteristics (VCC = +5V, VEE = 0V, CL = 15pF, VOVERDRIVE = 100mV, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VCC = +5V, VEE = 0V, CL = 15pF, VOVERDRIVE = 100mV, TA = +25°C, unless otherwise noted.) SHORT-CIRCUIT SINK CURRENT vs. TEMPERATURE TA = +25°C TA = +85°C 0.2 30 25 20 15 VCC = +3V 10 1 2 3 4 5 6 7 8 9 10 25 20 VCC = +3V 15 VCC = +1.8V 0 -40 -15 10 35 60 85 -40 -15 10 35 60 85 SOURCE CURRENT (mA) TEMPERATURE (°C) TEMPERATURE (°C) OFFSET VOLTAGE vs. TEMPERATURE HYSTERESIS VOLTAGE vs. TEMPERATURE MAX9117/MAX9118 REFERENCE VOLTAGE vs. TEMPERATURE 0.9 1.258 VHB (mV) 0.7 0.6 4.5 4.0 0.5 0.4 VCC = +5V -15 10 35 60 3.0 -40 85 1.252 VCC = +3V VCC = +1.8V 1.250 1.248 1.246 1.242 0.3 -40 1.254 1.244 3.5 0.2 VCC = +5V 1.256 5.0 VCC = +3V 0.8 MAX9117-20 toc15 5.5 REFERENCE VOLTAGE (V) VCC = +1.8V 1.260 MAX9117-20 toc14 1.1 1.0 6.0 MAX9117-20 toc13 1.2 -15 10 35 60 1.240 -40 85 -15 10 35 60 85 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) MAX9117/MAX9118 REFERENCE VOLTAGE vs. SUPPLY VOLTAGE MAX9117/MAX9118 REFERENCE OUTPUT VOLTAGE vs. REFERENCE SOURCE CURRENT MAX9117/MAX9118 REFERENCE OUTPUT VOLTAGE vs. REFERENCE SINK CURRENT 1.252 1.251 1.250 1.249 1.5 1.256 1.254 1.252 1.250 VCC = +1.8V, +3V 1.248 VCC = +5V 1.246 2.5 3.0 3.5 4.0 4.5 SUPPLY VOLTAGE (V) 5.0 5.5 1.258 1.256 VCC = +5V 1.254 1.252 1.250 VCC = +3V VCC = +1.8V 1.248 1.246 1.244 1.244 1.242 1.242 1.240 2.0 1.260 MAX9117-20 toc18 MAX9117-20 toc17 1.258 REFERENCE VOLTAGE (V) 1.253 1.260 REFERENCE VOLTAGE (V) MAX9117-20 toc16 1.254 6 30 5 0 0 VCC = +5V 35 10 VCC = +1.8V 5 0 VOS (mV) 45 40 TA = -40°C 0.1 MAX9117-20 toc12 VCC = +5V 50 SOURCE CURRENT (mA) 0.4 0.3 35 SINK CURRENT (mA) 0.5 VCC - VOH (V) 40 MAX9117-20 toc10 0.6 MAX9117/MAX9119 SHORT-CIRCUIT SOURCE CURRENT vs. TEMPERATURE MAX9117-20 toc11 MAX9117/MAX9119 OUTPUT VOLTAGE HIGH vs. SOURCE CURRENT AND TEMPERATURE REFERENCE VOLTAGE (V) MAX9117–MAX9120 SC70, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Reference 1.240 0 1 2 3 4 5 6 7 SOURCE CURRENT (nA) 8 9 10 0 1 2 3 4 5 6 7 SINK CURRENT (nA) _______________________________________________________________________________________ 8 9 10 SC70, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Reference MAX9117/MAX9119 PROPAGATION DELAY (tPD+) vs. TEMPERATURE 26 24 50 16 30 VCC = +3V 10 10 -15 10 35 60 20 -40 -15 10 35 60 0 0.01 85 0.1 1 10 CAPACITIVE LOAD (nF) MAX9117/MAX9119 PROPAGATION DELAY (tPD+) vs. CAPACITIVE LOAD PROPAGATION DELAY (tPD-) vs. INPUT OVERDRIVE MAX9117/MAX9119 PROPAGATION DELAY (tPD+) vs. INPUT OVERDRIVE 70 40 30 80 VCC = +3V VCC = +5V 60 tPD+ (µs) tPD- (µs) 100 50 VCC = +1.8V 40 20 10 100 0 0 1000 VCC = +1.8V 5 VCC = +3V 10 1 VCC = +3V 20 10 40 0.1 25 15 VCC = +5V 30 20 VCC = +5V 35 60 120 10 20 30 40 50 0 10 20 30 INPUT OVERDRIVE (mV) INPUT OVERDRIVE (mV) MAX9118/MAX9120 PROPAGATION DELAY (tPD-) vs. PULLUP RESISTANCE MAX9118/MAX9120 PROPAGATION DELAY (tPD+) vs. PULLUP RESISTANCE PROPAGATION DELAY (tPD-) (VCC = +5V) MAX9117-20 toc26 MAX9117-20 toc25 VCC = +1.8V 80 tPD+ (µs) VCC = +3V 50 MAX9117-20 toc27 100 IN+ (50mV/div) 13 tPD- (µs) 40 CAPACITIVE LOAD (nF) 15 1000 MAX9117-20 toc24 80 MAX9117-20 toc23 VCC = +1.8V 140 12 100 TEMPERATURE (°C) 160 14 VCC = +5V TEMPERATURE (°C) 180 0 0.01 VCC = +3V 40 VCC = +1.8V 0 85 MAX9117-20 toc22 -40 100 60 VCC = +5V 8 120 80 20 12 tPD+ (µs) 140 VCC = +3V 14 VCC = +1.8V 160 tPD- (µs) 18 180 VCC = +5V 40 VCC = +1.8V tPD+ (µs) tPD- (µs) 22 20 200 MAX9117-20 toc20 60 MAX9117-20 toc19 28 PROPAGATION DELAY (tPD-) vs. CAPACITIVE LOAD MAX9117-20 toc21 PROPAGATION DELAY (tPD-) vs. TEMPERATURE OV 60 VCC = +5V 40 VCC = +3V 11 OUT (2V/div) 20 10 OV VCC = +1.8V VCC = +5V 9 0 10 100 1000 RPULLUP (kΩ) 10,000 10 100 1000 10,000 20µs/div RPULLUP (kΩ) _______________________________________________________________________________________ 7 MAX9117–MAX9120 Typical Operating Characteristics (continued) (VCC = +5V, VEE = 0V, CL = 15pF, VOVERDRIVE = 100mV, TA = +25°C, unless otherwise noted.) MAX9117–MAX9120 SC70, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Reference Typical Operating Characteristics (continued) (VCC = +5V, VEE = 0V, CL = 15pF, VOVERDRIVE = 100mV, TA = +25°C, unless otherwise noted.) MAX9117/MAX9119 PROPAGATION DELAY (tPD+) (VCC = +5V) MAX9117/MAX9119 PROPAGATION DELAY (tPD+) (VCC = +3V) PROPAGATION DELAY (tPD-) (VCC = +3V) MAX9117-20 toc29 MAX9117-20 toc28 MAX9117-20 toc30 IN+ (50mV/div) IN+ (50mV/div) IN+ (50mV/div) OV OV OV OUT (2V/div) OUT (2V/div) OV OUT (2V/div) OV OV 20µs/div 20µs/div 20µs/div PROPAGATION DELAY (tPD-) (VCC = +1.8V) MAX9117/MAX9119 PROPAGATION DELAY (tPD+) (VCC = +1.8V) MAX9117/MAX9119 10kHz RESPONSE (VCC = +1.8V) MAX9117-20 toc31 MAX9117-20 toc32 MAX9117-20 toc33 IN+ (50mV/div) IN+ (50mV/div) IN+ (50mV/div) OV OV OV OUT (1V/div) OV OUT (1V/div) OV OUT (1V/div) 20µs/div OV 20µs/div 20µs/div MAX9117/MAX9119 1kHz RESPONSE (VCC = +5V) POWER-UP/DOWN RESPONSE MAX9117-20 toc34 MAX9117-20 toc35 IN+ (50mV/div) VCC (2V/div) OV OV OUT (2V/div) OUT (2V/div) OV OV 200µs/div 8 40µs/div _______________________________________________________________________________________ SC70, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Reference VCC VCC IN+ IN+ OUT REF OUT IN- MAX9119 MAX9120 MAX9117 MAX9118 REF 1.252V VEE VEE Pin Description mum of 6V above VEE. These open-drain versions are ideal for implementing wire-OR output logic functions. PIN MAX9117/ MAX 9118 MAX9119/ MAX 9120 NAME FUNCTION 1 1 OUT Comparator Output 2 2 VEE Negative Supply Voltage 3 3 IN+ Comparator Noninverting Input 4 — REF 1.252V Reference Output 5 5 VCC Positive Supply Voltage 4 IN- Comparator Inverting Input Detailed Description The MAX9117/MAX9118 feature an on-board 1.252V ±1.75% reference, yet draw an ultra-low supply current of 600nA. The MAX9119/MAX9120 (without reference) consume just 350nA of supply current. All four devices are guaranteed to operate down to +1.8V. Their common-mode input voltage range extends 200mV beyond-the-rails. Internal hysteresis ensures clean output switching, even with slow-moving input signals. Large internal output drivers allow rail-to-rail output swing with up to ±5mA loads. The output stage employs a unique design that minimizes supply-current surges while switching, virtually eliminating the supply glitches typical of many other comparators. The MAX9117/MAX9119 have a push-pull output stage that sinks as well as sources current. The MAX9118/MAX9120 have an open-drain output stage that can be pulled beyond VCC to an absolute maxi- Input Stage Circuitry The input common-mode voltage range extends from VEE - 0.2V to VCC + 0.2V. These comparators operate at any differential input voltage within these limits. Input bias current is typically ±0.15nA if the input voltage is between the supply rails. Comparator inputs are protected from overvoltage by internal ESD protection diodes connected to the supply rails. As the input voltage exceeds the supply rails, these ESD protection diodes become forward biased and begin to conduct. Output Stage Circuitry The MAX9117–MAX9120 contain a unique breakbefore-make output stage capable of rail-to-rail operation with up to ±5mA loads. Many comparators consume orders of magnitude more current during switching than during steady-state operation. However, with this family of comparators, the supply-current change during an output transition is extremely small. In the Typical Operating Characteristics, the Supply Current vs. Output Transition Frequency graphs show the minimal supply-current increase as the output switching frequency approaches 1kHz. This characteristic reduces the need for power-supply filter capacitors to reduce glitches created by comparator switching currents. In battery-powered applications, this characteristic results in a substantial increase in battery life. _______________________________________________________________________________________ 9 MAX9117–MAX9120 Functional Diagrams MAX9117–MAX9120 SC70, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Reference Reference (MAX9117/MAX9118) The internal reference in the MAX9117/MAX9118 has an output voltage of +1.252V with respect to VEE. Its typical temperature coefficient is 100ppm/°C over the full -40°C to +85°C temperature range. The reference is a PNP emitter-follower driven by a 120nA current source (Figure 1). The output impedance of the voltage reference is typically 200kΩ, preventing the reference from driving large loads. The reference can be bypassed with a low-leakage capacitor. The reference is stable for any capacitive load. For applications requiring a lower output impedance, buffer the reference with a low-input-leakage op amp, such as the MAX4162. Applications Information Low-Voltage, Low-Power Operation The MAX9117–MAX9120 are ideally suited for use with most battery-powered systems. Table 1 lists a variety of battery types, capacities, and approximate operating times for the MAX9117–MAX9120, assuming nominal conditions. Internal Hysteresis Many comparators oscillate in the linear region of operation because of noise or undesired parasitic feedback. This tends to occur when the voltage on one input is equal or very close to the voltage on the other input. The MAX9117–MAX9120 have internal hysteresis to counter parasitic effects and noise. The hysteresis in a comparator creates two trip points: one for the rising input voltage (VTHR) and one for the falling input voltage (VTHF) (Figure 2). The difference between the trip points is the hysteresis (VHB). When the comparator’s input voltages are equal, the hysteresis effectively causes one comparator input to move quickly past the other, thus taking the input out of the VCC 120nA REF VBIAS VEE Figure 1. MAX9117/MAX9118 Voltage Reference Output Equivalent Circuit region where oscillation occurs. Figure 2 illustrates the case in which IN- has a fixed voltage applied, and IN+ is varied. If the inputs were reversed, the figure would be the same, except with an inverted output. Additional Hysteresis (MAX9117/MAX9119) The MAX9117/MAX9119 have a 4mV internal hysteresis band (VHB). Additional hysteresis can be generated with three resistors using positive feedback (Figure 3). Unfortunately, this method also slows hysteresis response time. Use the following procedure to calculate resistor values. 1) Select R3. Leakage current at IN is under 2nA, so the current through R3 should be at least 0.2µA to minimize errors caused by leakage current. The current through R3 at the trip point is (VREF - VOUT) / R3. Considering the two possible output states in solving for R3 yields two formulas: R3 = VREF / IR3 or R3 = (VCC - VREF) / IR3. Use the smaller of the two resulting resistor values. For example, when using the Table 1. Battery Applications Using MAX9117–MAX9120 BATTERY TYPE RECHARGEABLE VFRESH (V) VEND-OF-LIFE (V) CAPACITY, AA SIZE (mA-h) MAX9117/MAX9118 OPERATING TIME (hr) MAX9119/MAX9120 OPERATING TIME (hr) Alkaline (2 Cells) No 3.0 1.8 2000 2.5 x 106 5 x 106 Nickel-Cadmium (2 Cells) Yes 2.4 1.8 750 937,500 1.875 x 106 Lithium-Ion (1 Cell) Yes 3.5 2.7 1000 1.25 x 106 2.5 x 106 Nickel-MetalHydride (2 Cells) Yes 2.4 1.8 1000 1.25 x 106 2.5 x 106 10 ______________________________________________________________________________________ SC70, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Reference R3 VTHR R1 HYSTERESIS INVHB VIN VCC BAND R2 VTHF OUT VEE VREF MAX9117 MAX9119 OUT Figure 2. Threshold Hysteresis Band Figure 3. MAX9117/MAX9119 Additional Hysteresis MAX9117 (VREF = 1.252V) and VCC = +5V, and if we choose IR3 = 1µA, then the two resistor values are 1.2MΩ and 3.8MΩ. Choose a 1.2MΩ standard value for R3. 2) Choose the hysteresis band required (VHB). For this example, choose 50mV. external pullup resistor (Figure 4). Additional hysteresis can be generated using positive feedback, but the formulas differ slightly from those of the MAX9117/ MAX9119. Use the following procedure to calculate resistor values. 3) Calculate R1 according to the following equation: R1 = R3 (VHB / VCC) For this example, insert the values: R1 = 1.2MΩ (50mV / 5V) = 12kΩ 4) Choose the trip point for VIN rising (VTHR) such that VTHR > VREF ✕ (R1 + R3) / R3, (VTHF is the trip point for VIN falling). This is the threshold voltage at which the comparator switches its output from low to high as VIN rises above the trip point. For this example, choose 3V. 5) Calculate R2 as follows: R2 = 1 / [VTHR / (VREF ✕ R1) - (1 / R1) - (1 / R3)] R2 = 1 / [3.0V / (1.2V ✕ 12kΩ) - (1 / 12kΩ) (1 / 1.2MΩ)] = 8.05kΩ For this example, choose an 8.2kΩ standard value. 6) Verify the trip voltages and hysteresis as follows: VIN rising: VTHR = VREF ✕ R1 [(1 / R1) + (1 / R2) + (1 / R3)] VIN falling: VTHF = VTHR - (R1 ✕ VCC / R3) Hysteresis = VTHR - VTHF Additional Hysteresis (MAX9118/MAX9120) 1) Select R3 according to the formulas R3 = VREF / 1µA or R3 = (VCC - VREF) / 1µA - R4. Use the smaller of the two resulting resistor values. 2) Choose the hysteresis band required (VHB). 3) Calculate R1 according to the following equation: R1 = (R3 + R4) (VHB / VCC) 4) Choose the trip point for VIN rising (VTHR) (VTHF is the trip point for VIN falling). This is the threshold voltage at which the comparator switches its output from low to high as VIN rises above the trip point. 5) Calculate R2 as follows: 1 1 R2 = 1 VTHR (VREF × R1) − − R1 R 3 6) Verify the trip voltages and hysteresis as follows: 1 1 1 VIN risin g : VTHR = VREF × R1 + + R1 R2 R 3 VIN falling : R1 1 1 1 VTHF = VREF × R1 + + × VCC − R1 R2 R 3 + R4 R 3 + R4 Hysteresis = VTHR - VTHF The MAX9118/MAX9120 have a 4mV internal hysteresis band. They have open-drain outputs and require an ______________________________________________________________________________________ 11 MAX9117–MAX9120 VCC THRESHOLDS IN+ MAX9117–MAX9120 SC70, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Reference Typical Application Circuit Board Layout and Bypassing Power-supply bypass capacitors are not typically needed, but use 100nF bypass capacitors close to the device’s supply pins when supply impedance is high, supply leads are long, or excessive noise is expected on the supply lines. Minimize signal trace lengths to reduce stray capacitance. A ground plane and surface-mount components are recommended. If the REF pin is decoupled, use a new low-leakage capacitor. +5V (+3V) +3V (+5V) 2MΩ VCC RPULLUP IN- Figure 5 shows a zero-crossing detector application. The MAX9119’s inverting input is connected to ground, and its noninverting input is connected to a 100mVP-P signal source. As the signal at the noninverting input crosses 0V, the comparator’s output changes state. Logic-Level Translator The Typical Application Circuit shows an application that converts 5V logic to 3V logic levels. The MAX9120 is powered by the +5V supply voltage, and the pullup resistor for the MAX9120’s open-drain output is connected to the +3V supply voltage. This configuration allows the full 5V logic swing without creating overvoltage on the 3V logic inputs. For 3V to 5V logic-level translations, simply connect the +3V supply voltage to VCC and the +5V supply voltage to the pullup resistor. 3V (5V) LOGIC OUT OUT Zero-Crossing Detector 2MΩ IN+ MAX9120 VEE 5V (3V) LOGIC IN LOGIC-LEVEL TRANSLATOR Chip Information TRANSISTOR COUNT: 98 VCC VCC R3 VCC 100mVP-P R1 R4 VIN VCC R2 OUT OUT IN- VEE VREF IN+ MAX9118 MAX9120 MAX9119 VEE Figure 4. MAX9118/MAX9120 Additional Hysteresis 12 Figure 5. Zero-Crossing Detector ______________________________________________________________________________________ SC70, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Reference SC70, 5L.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 ____________________ 13 © 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX9117–MAX9120 Package Information (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.)