LMV762MA

LMV761/LMV762 Low Voltage, Precision Comparator with Push-Pull Output October 31, 2008 LMV761/LMV762 Low Voltage, Precision Comparator with Push-Pull Output General Description The LMV761/LMV762 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 6-Pin SOT-23 or 8-Pin SOIC package. The LMV762 dual is available in 8-Pin SOIC or MSOP package. 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/LMV762 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. Features (VS = 5V, TA = 25°C, typical values unless specified). 0.2mV ■ Input offset voltage 1mV ■ Input offset voltage (max over temp) 0.2pA ■ Input bias current 120 nsec ■ Propagation delay (OD = 50mV) 300μA ■ Low supply current 100dB ■ CMRR 110dB ■ PSRR −40°C to 125°C ■ Extended Temperature Range ■ Push-pull output ■ Ideal for 2.7V and 5V single supply applications ■ Available in space-saving packages: 6-Pin SOT-23 (single w/shutdown) 8-Pin SOIC (single w/shutdown) 8-Pin SOIC/MSOP (dual without shutdown) Applications ■ ■ ■ ■ ■ ■ ■ 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 Typical Circuit 20037032 Threshold Detector 20037010 © 2008 National Semiconductor Corporation 200370 www.national.com LMV761/LMV762 Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. ESD Tolerance (Note 2) Human Body Model Machine Model Supply Voltage (V+ – V−) Differential Input Voltage Voltage between any two pins Output Short Circuit Duration (Note 9) Current at Input Pin 2000V 200V 5.5V Supply Voltage Supply Voltage ±5 mA Soldering Information Infrared or Convection (20 sec.) Wave Soldering (10 sec.) Junction Temperature Storage Temperature Range 235°C 260°C (Lead Temp) 150°C −65°C to 150°C Operating Ratings Supply Voltage (V+ – V−) Temperature Range Package Thermal Resistance (Note 4) 6-Pin SOT-23 8-Pin SOIC 8-Pin MSOP 2.7V to 5.0V −40°C to +125°C 265°C/W 190°C/W 235°C/W 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 VOS IB IOS CMRR PSRR CMVR VO ISC IS Parameter Input Offset Voltage Input Bias Current (Note 8) Input Offset Current (Note 8) Common Mode Rejection Ratio Power Supply Rejection Ratio Input Common Mode Voltage Range Output Swing High Output Swing Low Output Short Circuit Current (Note 3) Supply Current LMV761 (Single Comparator) LMV762 (Both Comparators) IOUT LEAKAGE Output Leakage I @ Shutdown IS LEAKAGE tPD Supply Leakage I @ Shutdown Propagation Delay RL = 5.1kΩ CL = 50pF Propagation Delay Skew Output Rise Time Output Fall Time Turn On Time From Shutdown 10% to 90% 90% to 10% SD = GND, VO = 2.7V SD = GND, VCC = 2.7V Overdrive = 5mV Overdrive = 10mV Overdrive = 50mV 0V < VCM < VCC - 1.3V V+ = 2.7V to 5V CMRR > 50dB IL = 2mA, VID = 200mV IL = −2mA, VID = −200mV Sourcing, VO = 1.35V, VID = 200mV Sinking, VO = 1.35V, VID = −200mV 6.0 6.0 V+ – 0.35 V+ – 0.1 90 20 15 275 550 0.20 0.20 270 205 120 5 1.7 1.8 6 ns ns ns μs ns 2 700 1400 μA μA 250 80 80 Condition Min (Note 7) Typ (Note 6) 0.2 0.2 .001 100 110 −0.3 1.5 Max (Note 7) 1.0 50 5 Units mV pA pA dB dB V V mV mA μA tSKEW tr tf ton www.national.com 2 LMV761/LMV762 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 VOS IB IOS CMRR PSRR CMVR VO ISC IS Parameter Input Offset Voltage Input Bias Current (Note 8) Input Offset Current (Note 8) Common Mode Rejection Ratio Power Supply Rejection Ratio Input Common Mode Voltage Range Output Swing High Output Swing Low Output Short Circuit Current (Note 3) Supply Current LMV761 (Single Comparator) LMV762 (Both Comparators) IOUT LEAKAGE Output Leakage I @ Shutdown IS LEAKAGE tPD Supply Leakage I @ Shutdown Propagation Delay RL = 5.1kΩ CL = 50pF Propagation Delay Skew Output Rise Time Output Fall Time Turn On Time from Shutdown 10% to 90% 90% to 10% SD = GND, VO = 5.0V SD = GND, VCC = 5.0V Overdrive = 5mV Overdrive = 10mV Overdrive = 50mV 0V < VCM < VCC - 1.3V V+ = 2.7V to 5V CMRR > 50dB IL = 4mA, VID = 200mV IL = −4mA, VID = −200mV Sourcing, VO = 2.5V, VID = 200mV Sinking, VO = 2.5V, VID = −200mV 6.0 6.0 V+ – 0.35 V+ – 0.1 120 60 40 225 450 0.20 0.20 225 190 120 5 1.7 1.5 4 ns ns ns μs ns 2 700 1400 μA μA 250 80 80 Condition Min (Note 7) Typ (Note 6) 0.2 0.2 0.01 100 110 −.3 3.8 Max (Note 7) 1.0 50 5 Units mV pA pA dB dB V V mV mA μA tSKEW tr tf ton 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 Note 9: 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 150°C. Output current in excess of ±25 mA over long term may adversely affect reliability. 3 www.national.com LMV761/LMV762 Connection Diagrams LMV761 (Single) 6-Pin SOT-23 LMV761 (Single) 8-Pin SOIC LMV762 (Dual) 8-Pin SOIC and MSOP 20037001 20037002 20037003 Top View Top View Top View Ordering Information Package 6-Pin SOT-23 Part Number LMV761MF LMV761MFX LMV761MA 8-Pin SOIC LMV761MAX LMV762MA LMV762MAX 8-Pin MSOP LMV762MM LMV762MMX Package Marking C22A LMV761MA LMV762MA C23A Transport Media 1k units Tape and Reel 3k units Tape and Reel 95 Units/Rail 2.5k Units Tape and Reel 95 Units/Rail 2.5k Units Tape and Reel 1k Units Tape and Reel 3.5k Units Tape and Reel MUA08A M08A NSC Drawing MF06A www.national.com 4 LMV761/LMV762 Typical Performance Characteristics PSI vs. VCC (VO = High) PSI vs. VCC (VO = Low) 20037004 20037005 VOS vs. VCC Input Bias vs. Common Mode @ 25°C 20037010 20037024 Input Bias vs. Common Mode @ 25°C Output Voltage vs. Supply Voltage 20037025 20037011 5 www.national.com LMV761/LMV762 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 20037007 20037008 www.national.com 6 LMV761/LMV762 ISINK vs. VOUT Prop Delay vs. Overdrive 20037009 20037019 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 Information 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 FIGURE 2. Non-Inverting Comparator Configuration INPUT The LMV761/LMV762 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/LMV762 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. 20037031 FIGURE 1. Basic Comparator 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 non-inverting 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. ΔVIN = 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 SOT-23 NS Package Number MF06A 8-Pin SOIC NS Package Number M08A 9 www.national.com LMV761/LMV762 8-Pin MSOP NS Package Number MUA08A www.national.com 10 LMV761/LMV762 Notes 11 www.national.com LMV761/LMV762 Low Voltage, Precision Comparator with Push-Pull Output Notes For more National Semiconductor product information and proven design tools, visit the following Web sites at: Products Amplifiers Audio Clock Conditioners Data Converters Displays Ethernet Interface LVDS Power Management Switching Regulators LDOs LED Lighting PowerWise Serial Digital Interface (SDI) Temperature Sensors Wireless (PLL/VCO) www.national.com/amplifiers www.national.com/audio www.national.com/timing www.national.com/adc www.national.com/displays www.national.com/ethernet www.national.com/interface www.national.com/lvds www.national.com/power www.national.com/switchers www.national.com/ldo www.national.com/led www.national.com/powerwise www.national.com/sdi www.national.com/tempsensors www.national.com/wireless WEBENCH Analog University App Notes Distributors Green Compliance Packaging Design Support www.national.com/webench www.national.com/AU www.national.com/appnotes www.national.com/contacts www.national.com/quality/green www.national.com/packaging www.national.com/quality www.national.com/refdesigns www.national.com/feedback Quality and Reliability Reference Designs Feedback THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION (“NATIONAL”) PRODUCTS. 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