LMC6772/LMC6772Q Dual Micropower Rail-To-Rail Input CMOS Comparator with Open Drain Output General Description Features The LMC6772 is an ultra low power dual comparator with a maximum 10 A/comparator power supply current. It is designed to operate over a wide range of supply voltages, with a minimum supply voltage of 2.7V. The common mode voltage range of the LMC6772 exceeds both the positive and negative supply rails, a significant advantage in single supply applications. The open drain output of the LMC6772 allows for wired-OR configurations. The open drain output also offers the advantage of allowing the output to be pulled to any voltage rail up to 15V, regardless of the supply voltage of the LMC6772. The LMC6772 is targeted for systems where low power consumption is the critical parameter. Guaranteed operation at supply voltages of 2.7V and rail-to-rail performance makes this comparator ideal for battery-powered applications. Refer to the LMC6762 datasheet for a push-pull output stage version of this device. (Typical unless otherwise noted) Low power consumption (max): IS = 10 A/comp Wide range of supply voltages: 2.7V to 15V Rail-to-Rail input common mode voltage range Open drain output Short circuit protection: 40 mA Propagation delay (@VS = 5V, 100 mV overdrive): 5 s LMC6772Q is AEC-Q qualified LMC6772Q has -40C to 125C temperature range Applications Laptop computers Mobile phones Metering systems Hand-held electronics RC timers Alarm and monitoring circuits Window comparators, multivibrators Connection Diagram 8-Pin MDIP/SOIC/MSOP 1234701 Top View (c) 2008 National Semiconductor Corporation 12347 www.national.com LMC6772/LMC6772Q Dual Micropower Rail-To-Rail Input CMOS Comparator with Open Drain Output December 2, 2008 LMC6772/LMC6772Q Storage Temperature Range Junction Temperature (Note 4) Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Operating Ratings -65C to 150C 150C (Note 1) 2.7 VS 15V Supply Voltage ESD Tolerance (Note 2) 1.5 kV Differential Input Voltage (V+)+0.3V to (V-)-0.3V Voltage at Input/Output Pin (V+)+0.3V to (V-)-0.3V Supply Voltage (V+-V-) 16V Current at Input Pin (Note 8) 5 mA Current at Output Pin (Notes 3, 7) 30 mA Current at Power Supply Pin, LMC6772 40 mA Lead Temperature (Soldering, 10 seconds) 260C Junction Temperature Range LMC6772AI, LMC6772BI 40C TJ 85C 40C TJ 125C LMC6772Q Thermal Resistance (JA) N Package, 8-Pin Molded DIP M Package, 8-Pin Surface Mount 100C/W 172C/W 2.7V Electrical Characteristics Unless otherwise specified, all limits guaranteed for TJ = 25C, V+ = 2.7V, V- = 0V, VCM = V+/2. Boldface limits apply at the temperature extremes. Symbol Parameter Conditions Typ LMC6772AI LMC6772BI LMC6772Q (Note 5) Limit Limit Limit (Note 6) (Note 6) (Note 6) VOS Input Offset Voltage 3 TCVOS Input Offset Voltage Temperature Drift 2.0 V/C 3.3 V/ Month Input Offset Voltage Average Drift (Note 10) 5 8 15 18 10 13 Units mV max IB Input Current 0.02 pA IOS Input Offset Current 0.01 pA CMRR Common Mode Rejection Ratio 75 dB PSRR Power Supply Rejection Ratio 1.35V < VS < 7.5V 80 dB AV Voltage Gain (By Design) 100 dB VCM Input Common-Mode Voltage Range CMRR > 55 dB 3.0 2.9 2.7 2.9 2.7 2.9 2.7 V min -0.3 -0.2 0.0 -0.2 0.0 -0.2 0.2 V max VOL Output Voltage Low ILOAD = 2.5 mA 0.2 0.3 0.4 0.3 0.4 0.3 0.45 V max IS Supply Current For Both Comparators (Output Low) 12 20 25 20 25 20 25 A max ILeakage Output Leakage Current VIN(+) = 0.5V, VIN(-) = 0V, VO = 15V 0.1 500 500 500 1000 nA www.national.com 2 Unless otherwise specified, all limits guaranteed for TJ = 25C, V+ = 5.0V and 15.0V, V- = 0V, VCM = V+/2. Boldface limits apply at the temperature extremes. Symbol Parameter VOS Input Offset Voltage TCVOS Input Offset Voltage Temperature Drift Input Offset Voltage Average Drift Conditions Typ LMC6772AI LMC6772BI LMC6772Q (Note 5) Limit Limit Limit (Note 6) (Note 6) (Note 6) 3 V+ = 5V 2.0 V+ = 15V 4.0 V+ = 5V (Note 10) 3.3 V+ = 15V (Note 10) 4.0 5 8 15 18 10 13 Units mV max V/C V/ Month IB Input Current V = 5V 0.04 pA IOS Input Offset Current V+ = 5V 0.02 pA Common Mode Rejection Ratio V+ CMRR = 5V 75 V+ = 15V dB 82 PSRR Power Supply Rejection Ratio 2.5V < VS < 5V 80 dB AV Voltage Gain (By Design) 100 dB Input Common-Mode Voltage Range V+ 5.3 5.2 5.0 5.2 5.0 5.2 5.0 V min -0.3 -0.2 0.0 -0.2 0.0 -0.2 0.0 Vmax 15.3 15.2 15.0 15.2 15.0 15.2 15.0 V min -0.3 -0.2 0.0 -0.2 0.0 -0.2 0.0 V max V+ = 5V ILOAD = 5 mA 0.2 0.4 0.55 0.4 0.55 0.4 0.55 V max V+ = 15V ILOAD = 5 mA 0.2 0.4 0.55 0.4 0.55 0.4 0.55 V max 20 25 20 25 20 25 A max VCM = 5.0V CMRR > 55 dB V+ = 15.0V CMRR > 55 dB VOL Output Voltage Low IS Supply Current For Both Comparators (Output Low) 12 ISC Short Circuit Current V+ = 15V, Sinking, VO = 12V (Note 7) 45 mA AC Electrical Characteristics Unless otherwise specified, all limits guaranteed for TJ = 25C, V+ = 5V, V- = 0V, VCM = VO = V+/2. Boldface limits apply at the temperature extreme. Symbol Parameter Conditions Typ (Note 5) LMC6772AI Limit (Note 6) LMC6772BI Limit (Note 6) Units tRISE Rise Time f = 10 kHz, CL = 50 pF, Overdrive = 10 mV (Note 9) 0.3 s tFALL Fall Time f = 10 kHz, CL = 50 pF, Overdrive = 10 mV (Note 9) 0.3 s 3 www.national.com LMC6772/LMC6772Q 5.0V and 15.0V Electrical Characteristics LMC6772/LMC6772Q Symbol tPHL Parameter Propagation Delay (High to Low) Conditions Typ (Note 5) LMC6772AI Limit (Note 6) LMC6772BI Limit (Note 6) Units 10 mV 10 s 100 mV 4 s 10 mV 10 s 100 mV 4 s f = 10 kHz, 10 mV 10 s CL = 50 pF 100 mV 4 s 10 mV 8 s 100 mV 4 s f = 10 kHz, CL = 50 pF (Note 9) V+ = 2.7V, f = 10 kHz, CL = 50 pF (Note 9) tPLH Propagation Delay (Low to High) (Note 9) V+ = 2.7V, f = 10 kHz, CL = 50 pF (Note 9) Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the electrical characteristics. Note 2: Human body model, 1.5 k in series with 100 pF. The output pins of the two comparators (pin 1 and pin 7) have an ESD tolerance of 1.5 kV. All other pins have an ESD tolerance of 2 kV. Note 3: Applies to both single-supply and split-supply operation. Continuous short circuit operation at elevated ambient temperature can result in exceeding the maximum allowed junction temperature of 150C. Output currents in excess of 30 mA over long term may adversely affect reliability. Note 4: The maximum power dissipation is a function of TJ(MAX), JA, and TA. The maximum allowable power dissipation at any ambient temperature is PD = (TJ(MAX) - TA)/JA. All numbers apply for packages soldered directly into a PC board. Note 5: Typical Values represent the most likely parametric norm. Note 6: All limits are guaranteed by testing or statistical analysis. Note 7: Do not short circuit output to V+, when V+ is > 12V or reliability will be adversely affected. Note 8: Limiting input pin current is only necessary for input voltages that exceed absolute maximum input voltage ratings. Note 9: CL inlcudes the probe and jig capacitance. The rise time, fall time and propagation delays are measured with a 2V input step. Note 10: Input offset voltage Average Drift is calculated by dividing the accelerated operating life drift average by the equivalent operational time. The input offset voltage average drift represents the input offset voltage change at worst-case input conditions. Ordering Information Package 8-Pin MDIP Temperature Range -40C to 85C Package Marking Transport Media NSC Drawing LMC6772BIN LMC6772BIN 40 Units/Rail N08E LMC6772AIM 8-Pin SOIC LMC6772AIMX LMC6772BIM LMC6772BIMX LMC6772AIMM 8-Pin MSOP LMC6772AIMMX LMC6772QMM LMC6772QMMX LMC6772AIM LMC6772BIM C21 AX5A Features 95 Units/Rail 2.5k Units Tape and Reel 95 Units/Rail M08A 2.5k Units Tape and Reel 1k Units Tape and Reel 3.5k Units Tape and Reel 1k Units Tape and Reel MUA08A AEC-Q100 Grade 1 qualified. Automotive Grade Production Flow* 3.5k Units Tape and Reel *Automotive Grade (Q) product incorporates enhanced manufacturing and support processes for the automotive market, including defect detection methodologies. Reliability qualification is compliant with the requirements and temperature grades defined in the AEC-Q100 standard. Automotive grade products are identified with the letter Q. For more information go to http://www.national.com/automotive. www.national.com 4 V+ = 5V, Single Supply, TA = 25C unless otherwise specified Supply Current vs. Supply Voltage (Output High) Supply Current vs. Supply Voltage (Output Low) 1234703 1234704 Input Current vs. Common-Mode Voltage Input Current vs. Common-Mode Voltage 1234705 1234706 Input Current vs. Common-Mode Voltage Input Current vs. Temperature 1234708 1234707 5 www.national.com LMC6772/LMC6772Q Typical Performance Characteristics LMC6772/LMC6772Q VOS vs VCM, VS = 2.7V VOS vs VCM, VS = 5V 1234709 1234710 VOS vs VCM, VS = 15V Output Voltage vs. Output Current (Sinking) 1234712 1234711 Output Voltage vs. Output Current (Sinking) Output Voltage vs. Output Current (Sinking) 1234713 www.national.com 1234714 6 LMC6772/LMC6772Q Output Short Circuit Current (Sinking) vs. Supply Voltage Leakage Current vs. Output Voltage 1234715 1234716 Response Time for Overdrive (tPLH) Response Time for Overdrive (tPHL) 1234717 1234718 Response Time for Overdrive (tPLH) Response Time for Overdrive (tPHL) 1234719 1234720 7 www.national.com LMC6772/LMC6772Q Response Time for Overdrive (tPLH) Response Time for Overdrive (tPHL) 1234721 1234722 Response Time vs. Capacitive Load 1234723 LMC6772Q Supply Current vs. Supply Voltage (Output High) Supply Current vs. Supply Voltage (Output Low) 1234734 1234733 www.national.com 8 Output Voltage vs. Output Current (Sinking) 1234735 1234736 Output Voltage vs. Output Current (Sinking) Output Short Circuit Current vs. Supply 1234738 1234737 Output Leakage vs. Output Voltage 1234739 9 www.national.com LMC6772/LMC6772Q Output Voltage vs. Output Current (Sinking) LMC6772/LMC6772Q Application Information 1.0 INPUT COMMON-MODE VOLTAGE RANGE At supply voltages of 2.7V, 5V and 15V, the LMC6772 has an input common-mode voltage range which exceeds both supplies. As in the case of operational amplifiers, CMVR is defined by the VOS shift of the comparator over the commonmode range of the device. A CMRR (VOS/VCM) of 75 dB (typical) implies a shift of < 1 mV over the entire commonmode range of the device. The absolute maximum input voltage at V+ = 5V is 200 mV beyond either supply rail at room temperature. 1234725 FIGURE 2. Even at Low-Supply Voltage of 2.7V, an Input Signal which Exceeds the Supply Voltages Produces No Phase Inversion at the Output At V+ = 2.7V, propagation delays are tPLH = 4 s and tPHL = 4 s with overdrives of 100 mV. Please refer to the performance curves for more extensive characterization. 3.0 OUTPUT SHORT CIRCUIT CURRENT The LMC6772 has short circuit protection of 40 mA. However, it is not designed to withstand continuous short circuits, transient voltage or current spikes, or shorts to any voltage beyond the supplies. A resistor is series with the output should reduce the effect of shorts. For outputs which send signals off PC boards additional protection devices, such as diodes to the supply rails, and varistors may be used. 1234724 FIGURE 1. An Input Signal Exceeds the LMC6772 Power Supply Voltages with No Output Phase Inversion 4.0 HYSTERESIS If the input signal is very noisy, the comparator output might trip several times as the input signal repeatedly passes through the threshold. This problem can be addressed by making use of hysteresis as shown below. A wide input voltage range means that the comparator can be used to sense signals close to ground and also to the power supplies. This is an extremely useful feature in power supply monitoring circuits. An input common-mode voltage range that exceeds the supplies, 20 fA input currents (typical), and a high input impedance makes the LMC6772 ideal for sensor applications. The LMC6772 can directly interface to sensors without the use of amplifiers or bias circuits. In circuits with sensors which produce outputs in the tens to hundreds of millivolts, the LMC6772 can compare the sensor signal with an appropriately small reference voltage. This reference voltage can be close to ground or the positive supply rail. 2.0 LOW VOLTAGE OPERATION Comparators are the common devices by which analog signals interface with digital circuits. The LMC6772 has been designed to operate at supply voltages of 2.7V, without sacrificing performance, to meet the demands of 3V digital systems. At supply voltages of 2.7V, the common-mode voltage range extends 200 mV (guaranteed) below the negative supply. This feature, in addition to the comparator being able to sense signals near the positive rail, is extremely useful in low voltage applications. www.national.com 1234726 FIGURE 3. Canceling the Effect of Input Capacitance The capacitor added across the feedback resistor increases the switching speed and provides more short term hysteresis. This can result in greater noise immunity for the circuit. 5.0 SPICE MACROMODEL A Spice Macromodel is available for the LMC6772. The model includes a simulation of: * Input common-mode voltage range * Quiescent and dynamic supply current * Input overdrive characteristics and many more characteristics as listed on the macromodel disk. 10 LMC6772/LMC6772Q Contact the National Semiconductor Customer Response Center at 1-800-272-9959 to obtain an operational amplifier spice model library disk. BI-STABLE MULTIVIBRATOR Typical Applications UNIVERSAL LOGIC LEVEL SHIFTER The output of the LMC6772 is the uncommitted drain of the output NMOS transistor. Many drains can be tied together to provide an output OR'ing function. An output pullup resistor can be connected to any available power supply voltage within the permitted power supply range. 1234730 FIGURE 6. Bi-Stable Multivibrator A bi-stable multivibrator has two stable states. The reference voltage is set up by the voltage divider of R2 and R3. A pulse applied to the SET terminal will switch the output of the comparator high. The resistor divider of R1, R4, and R5 now clamps the non-inverting input to a voltage greater than the reference voltage. A pulse applied to RESET will now toggle the output low. 1234727 ZERO CROSSING DETECTOR FIGURE 4. Universal Logic Level Shifter The two 1 k resistors bias the input to half of the power supply voltage. The pull-up resistor should go to the output logic supply. Due to its wide operating range, the LMC6772 is ideal for the logic level shifting applications. ONE-SHOT MULTIVIBRATOR 1234729 FIGURE 7. Zero Crossing Detector A voltage divider of R4 and R5 establishes a reference voltage V1 at the non-inverting input. By making the series resistance of R1 and R2 equal to R5, the comparator will switch when VIN = 0. Diode D1 insures that V3 never drops below -0.7V. The voltage divider of R2 and R3 then prevents V2 from going below ground. A small amount of hysteresis is setup to ensure rapid output voltage transitions. 1234728 FIGURE 5. One-Shot Multivibrator A monostable multivibrator has one stable state in which it can remain indefinitely. It can be triggered externally to another quasi-stable state. A monostable multivibrator can thus be used to generate a pulse of desired width. The desired pulse width is set by adjusting the values of C2 and R4. The resistor divider of R1 and R2 can be used to determine the magnitude of the input trigger pulse. The LMC6772 will change state when V1 < V2. Diode D2 provides a rapid discharge path for capacitor C2 to reset at the end of the pulse. The diode also prevents the non-inverting input from being driven below ground. 11 www.national.com LMC6772/LMC6772Q Figure 8 shows the application of the LMC6772 in a square wave generator circuit. The total hysteresis of the loop is set by R1, R2 and R3. R4 and R5 provide separate charge and discharge paths for the capacitor C. The charge path is set through R4 and D1. So, the pulse width t1 is determined by the RC time constant of R4 and C. Similarly, the discharge path for the capacitor is set by R5 and D2. Thus, the time t2 between the pulses can be changed by varying R5, and the pulse width can be altered by R4. The frequency of the output can be changed by varying both R4 and R5. OSCILLATOR 1234731 FIGURE 8. Square Wave Generator Time Delay Generator 1234732 FIGURE 9. Time Delay Generator The circuit shown above provides output signals at a prescribed time interval from a time reference and automatically resets the output when the input returns to ground. Consider the case of VIN = 0. The output of comparator 4 is also at ground. This implies that the outputs of comparators 1, 2, and 3 are also at ground. When an input signal is applied, the output of comparator 4 swings high and C charges exponentially www.national.com through R. This is indicated above. The output voltages of comparators 1, 2, and 3 swtich to the high state when VC1 rises above the reference voltages VA, VB and VC. A small amount of hysteresis has been provided to insure fast switching when the RC time constant is chosen to give long delay times. 12 LMC6772/LMC6772Q Physical Dimensions inches (millimeters) unless otherwise noted 8-Pin MDIP NS Package Number N08E 8-Pin SOIC NS Package Number M08A 13 www.national.com LMC6772/LMC6772Q 8-Pin MSOP NS Package Number MUA08A www.national.com 14 LMC6772/LMC6772Q Notes 15 www.national.com LMC6772/LMC6772Q Dual Micropower Rail-To-Rail Input CMOS Comparator with Open Drain Output Notes For more National Semiconductor product information and proven design tools, visit the following Web sites at: Products Design Support Amplifiers www.national.com/amplifiers WEBENCH(R) Tools www.national.com/webench Audio www.national.com/audio App Notes www.national.com/appnotes Clock and Timing www.national.com/timing Reference Designs www.national.com/refdesigns Data Converters www.national.com/adc Samples www.national.com/samples Interface www.national.com/interface Eval Boards www.national.com/evalboards LVDS www.national.com/lvds Packaging www.national.com/packaging Power Management www.national.com/power Green Compliance www.national.com/quality/green Switching Regulators www.national.com/switchers Distributors www.national.com/contacts LDOs www.national.com/ldo Quality and Reliability www.national.com/quality LED Lighting www.national.com/led Feedback/Support www.national.com/feedback Voltage Reference www.national.com/vref Design Made Easy www.national.com/easy PowerWise(R) Solutions www.national.com/powerwise Solutions www.national.com/solutions Serial Digital Interface (SDI) www.national.com/sdi Mil/Aero www.national.com/milaero Temperature Sensors www.national.com/tempsensors Solar Magic(R) www.national.com/solarmagic Wireless (PLL/VCO) www.national.com/wireless Analog University(R) www.national.com/AU THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION ("NATIONAL") PRODUCTS. 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