LMV761/LMV762 Low Voltage, Precision Comparator with Push-Pull Output General Description Features The LMV761/762 are precision comparators intended for applications requiring low noise and low input offset voltage. The LV761 single has a shutdown pin that can be used to disable the device and reduce the supply current. The LMV761 is available in a space saving SOT23-6 or SOIC−8 package. The LMV762 dual is available in SOIC−8 or MSOP-8 package. (VS = 5V, TA = 25˚C, Typical values unless specified) n Input offset voltage 0.2mV n Input offset voltage (max over temp) 1mV n Input bias current 0.2pA n Propagation delay (OD = 50mV) 120 nsec n Low supply current 300µA n CMRR 100dB n PSRR 110dB n Extended Temperature Range −40˚C to 125˚C n Push-pull output n Ideal for 2.7V and 5V single supply applications n Available in space-saving packages: 6-Pin SOT23 (single w/shutdown) 8-Pin SOIC (single w/shutdown) 8-Pin SOIC/MSOP (dual without shutdown) They feature a CMOS input and Push-Pull output stage. The Push-Pull output stage eliminates the need for an external pull-up resistor. The LMV761/762 are designed to meet the demands of small size, low power and high performance required by portable and battery operated electronics. The input offset voltage has a typical value of 200µV at room temp and a 1mV limit over temp. Applications n n n n n n n Typical Circuit Portable and battery-powered systems Scanners Set top boxes High speed differential line receiver Window comparators Zero-crossing detectors High speed sampling circuits VOS vs. VCC 20037032 Threshold Detector 20037010 © 2002 National Semiconductor Corporation DS200370 www.national.com LMV761/LMV762 Low Voltage, Precision Comparator with Push-Pull Output July 2002 LMV761/LMV762 Absolute Maximum Ratings Wave Soldering (10 sec.) (Note 1) Junction Temperature If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (V+ – V−) 200V Supply Voltage (V+ – V−) 5.5V Temperature Range Differential Input Voltage Supply Voltage Voltage between any two pins Supply Voltage −65˚C to 150˚C Operating Ratings 2000V Machine Model 150˚C Storage Temperature Range ESD Tolerance (Note 2) Human Body Model 260˚C (Lead Temp) 2.7V to 5.0V −40˚C to +125˚C Package Thermal Resistance (Note 4) SOT23-6 265˚C/W Output Short Circuit to V+ - V− SOIC-8 190˚C/W Soldering Information MSOP-8 235˚C/W Infrared or Convection (20 sec.) 235˚C 2.7V Electrical Characteristics Unless otherwise specified, all limited guaranteed for TJ = 25˚C, VCM = V+/2, V+ = 2.7V, V− = 0V−. Boldface limits apply at the temperature extremes. (Note 5) Symbol Parameter Condition Min (Note 7) Typ (Note 6) Max (Note 7) Units VOS Input Offset Voltage 0.2 1.0 mV IB Input Bias Current (Note 8) 0.2 50 pA IOS Input Offset Current (Note 8) .001 5 pA CMRR Common Mode Rejection Ratio 0V < VCM < VCC - 1.3V 80 100 dB PSRR Power Supply Rejection Ratio V+ = 2.7V to 5V 80 110 dB CMVR Input Common Mode Voltage Range CMRR > 50dB VO Output Swing High IL = 2mA, VID = 200mV Output Swing Low IL = −2mA, VID = −200mV Output Short Circuit Current (Note 3) Sourcing, VO = 1.35V, VID = 200mV 6.0 20 Sinking, VO = 1.35V, VID = −200mV 6.0 15 ISC IS V+ – 0.35 −0.3 1.5 V 250 mV V+ – 0.1 90 V mA Supply Current LMV761 (Single Comparator) LMV762 (Both Comparators) 275 700 550 1400 Output Leakage I @ Shutdown SD = GND, VO = 2.7V 0.20 IS LEAKAGE Supply Leakage I @ Shutdown SD = GND, VCC = 2.7V 0.20 tPD Propagation Delay RL = 5.1kΩ CL = 50pF Overdrive = 5mV 270 Overdrive = 10mV 205 Overdrive = 50mV 120 IOUT µA µA LEAKAGE tSKEW Propagation Delay Skew tr Output Rise Time tf Output Fall Time ton Turn On Time From Shutdown 2 µA ns 5 ns 10% to 90% 1.7 ns 90% to 10% 1.8 ns 6 µs 5.0V Electrical Characteristics Unless otherwise specified, all limited guaranteed for TJ = 25˚C, VCM = V+/2, V+ = 5.0V, V− = 0V−. Boldface limits apply at the temperature extremes. Symbol Parameter Condition Min (Note 7) Typ (Note 6) Max (Note 7) Units VOS Input Offset Voltage 0.2 1.0 mV IB Input Bias Current (Note 8) 0.2 50 pA www.national.com 2 (Continued) Unless otherwise specified, all limited guaranteed for TJ = 25˚C, VCM = V+/2, V+ = 5.0V, V− = 0V−. Boldface limits apply at the temperature extremes. Symbol Parameter Condition Min (Note 7) Typ (Note 6) Max (Note 7) Units 0.01 5 pA IOS Input Offset Current (Note 8) CMRR Common Mode Rejection Ratio 0V < VCM < VCC - 1.3V 80 100 PSRR Power Supply Rejection Ratio V+ = 2.7V to 5V 80 110 CMVR Input Common Mode Voltage Range CMRR > 50dB VO Output Swing High IL = 4mA, VID = 200mV Output Swing Low IL = −4mA, VID = −200mV Output Short Circuit Current (Note 3) Sourcing, VO = 2.5V, VID = 200mV 6.0 60 Sinking, VO = 2.5V, VID = −200mV 6.0 40 ISC IS V+ – 0.35 dB dB −.3 3.8 V 250 mV V+ – 0.1 120 V mA Supply Current IOUT LMV761 (Single Comparator) 225 700 LMV762 (Both Comparators) 450 1400 Output Leakage I @ Shutdown SD = GND, VO = 5.0V 0.20 µA µA LEAKAGE IS LEAKAGE Supply Leakage I @ Shutdown SD = GND, VCC = 5.0V 0.20 tPD Propagation Delay RL = 5.1kΩ CL = 50pF Overdrive = 5mV 225 Overdrive = 10mV 190 Overdrive = 50mV 120 2 µA ns tSKEW Propagation Delay Skew 5 ns tr Output Rise Time 10% to 90% 1.7 ns tf Output Fall Time 90% to 10% 1.5 ns ton Turn On Time from Shutdown 4 µs 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 condition, see the Electrical Characteristics. Note 2: Unless otherwise specified human body model is 1.5kΩ in series with 100pF. Machine model 200pF. Note 3: Electrical Table values apply only for factory testing conditions at the temperature indicated. Factory testing conditions result in very limited self-heating of the device such that TJ = TA. No guarantee of parametric performance is indicated in the electrical tables under conditions of internal self-heating where TJ > TA. See Application section for information on temperature de-rating of this device. Absolute Maximum Rating indicate junction temperature limits beyond which the device may be permanently degraded, either mechanically or electrically. Note 4: The maximum power dissipation is a function of TJ(MAX), θJA, and TA. The maximum allowable power dissipation at any ambient temperature is PD = (TJ(MAX)-TA)θJA. All numbers apply for packages soldered directly into a PC board. Note 5: Maximum temperature guarantee range is −40˚C to 125˚C. Note 6: Typical values represent the most likely parametric norm. Note 7: All limits are guaranteed by testing or statistical analysis. Note 8: Guaranteed by design 3 www.national.com LMV761/LMV762 5.0V Electrical Characteristics LMV761/LMV762 Connection Diagrams LMV761 Single 6-Pin SOT23 LMV761 Single 8-Pin SOIC LMV762 Dual 8-Pin SOIC & MSOP 20037003 20037002 20037001 Top View Top View Top View Ordering Information Package 6-Pin SOT23 Part Number Package Marking Transport Media NSC Drawing LMV761MF C22A 1k units Tape and Reel MF06A LMV761MFX 8-Pin SOIC LMV761MA 3k units Tape and Reel LMV761MA Rail LMV761MAX 8-Pin SOIC LMV762MA LMV762MA Rail LMV762MAX 8-Pin MSOP LMV762MM M08A 2.5k Units Tape and Reel C23A 1k Units Tape and Reel LMV762MMX www.national.com M08A 2.5k Units Tape and Reel 3.5k Units Tape and Reel 4 MUA08A LMV761/LMV762 Typical Performance Characteristics PSI vs. VCC (VO = High) PSI vs. VCC (VO = Low) 20037004 20037005 Input Bias vs. Common Mode @ 25˚C VOS vs. VCC 20037024 20037010 Input Bias vs. Common Mode @ 25˚C Output Voltage vs. Supply Voltage 20037025 20037011 5 www.national.com LMV761/LMV762 Typical Performance Characteristics (Continued) Output Voltage vs. Supply Voltage Output Voltage vs. Supply Voltage 20037012 20037013 Output Voltage vs. Supply Voltage ISOURCE vs. VOUT 20037014 20037006 ISINK vs. VOUT ISOURCE vs. VOUT 20037008 20037007 www.national.com 6 LMV761/LMV762 Typical Performance Characteristics (Continued) ISINK vs. VOUT Prop Delay vs. Overdrive 20037019 20037009 Response Time vs. Input Overdrives Positive Transition Response Time vs. Input Overdrives Positive Transition 20037020 20037021 Response Time vs. Input Overdrives Negative Transition Response Time vs. Input Overdrives Negative Transition 20037022 20037023 7 www.national.com LMV761/LMV762 Application Hints Basic Comparator A basic comparator circuit is used to convert analog input signals to digital output signals. The comparator compares an input voltage (VIN) at the non-inverting input to the reference voltage (VREF) at the inverting pin. If VIN is less than VREF the output (VO) is low (VOL). However, if VIN is greater than VREF, the output voltage (VO) is high (VOH). 20037026 20037028 20037027 20037031 FIGURE 2. Non-Inverting Comparator Configuration FIGURE 1. Basic Comparator Input The LMV761/762 have near zero input bias current. This allows very high resistance circuits to be used without any concern for matching input resistances. This also allows the use of very small capacitors in R-C type timing circuits. This reduces the cost of the capacitors and amount of board space used. Shutdown Mode The LMV761 features a low-power shutdown pin that is activated by driving SD low. In shutdown mode, the output is in a high impedance state, supply current is reduced to 20nA and the comparator is disabled. Driving SD high will turn the comparator on. The SD pin should not be left unconnected due to the fact that it is a high impedance input. When left unconnected, the output will be at an unknown voltage. Also do not three-state the SD pin. The maximum input voltage for SD is 5.5V, referred to ground and is not limited by VCC. This allows the use of 5V logic to drive SD while VCC operates at a lower voltage, such as 3V. The logic threshold limits for SD are proportional to VCC. Board Layout and Bypassing The LMV761/762 is designed to be stable and oscillation free, but it is still important to include the proper bypass capacitors and ground pickups. Ceramic 0.1µF capacitors should be placed at both supplies to provide clean switching. Minimize the length of signal traces to reduce stray capacitance. Hysteresis The basic comparator configuration may oscillate or produce a noisy output if the applied differential input is near the comparator’s input offset voltage. This tends to occur when the voltage on one input is equal or very close to the other input voltage. Adding hysteresis can prevent this problem. Hysteresis creates two switching thresholds (one for the rising input voltage and the other for the falling input voltage). Hysteresis is the voltage difference between the two switching thresholds. When both inputs are nearly equal, hysteresis causes one input to effectively move quickly past the other. Thus, moving the input out of the region in which oscillation may occur. Hysteresis can easily be added to a comparator in a noninverting configuration with two resistors and positive feedback Figure 2. The output will switch from low to high when VIN rises up to VIN1, where VIN1 is calculated by VIN1 = (VREF(R1+R2))/R2 The output will switch from high to low when VIN falls to VIN2, where VIN2 is calculated by VIN2 = (VREF(R1+R2) – VCC R1)/R2 The Hysteresis is the difference between VIN1 and VIN2. ∆VIN = VIN1 - VIN2 = ((VREF(R1+R2))/R2)-((VREF(R1+R2)) - (VCC R1))/R2) = VCC R1/R2 www.national.com 8 LMV761/LMV762 Physical Dimensions inches (millimeters) unless otherwise noted 6-Pin SOT23 NS Package Number MF06A 8-Pin SOIC NS Package Number M08A 9 www.national.com LMV761/LMV762 Low Voltage, Precision Comparator with Push-Pull Output Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 8-Pin MSOP NS Package Number MUA08A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. 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