LMV761/LMV762 Low Voltage, Precision Comparator with Push-Pull Output
July 2002
LMV761/LMV762 Low Voltage, Precision Comparator with Push-Pull Output
General Description
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. 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.
Features
(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)
Applications
n n n n n n n Portable and battery-powered systems Scanners Set top boxes High speed differential line receiver Window comparators Zero-crossing detectors High speed sampling circuits
Typical Circuit
VOS vs. VCC
20037032
Threshold Detector
20037010
© 2002 National Semiconductor Corporation
DS200370
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LMV761/LMV762
Absolute Maximum Ratings
(Note 1)
Wave Soldering (10 sec.) Junction Temperature Storage Temperature Range
260˚C (Lead Temp) 150˚C −65˚C to 150˚C
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 to V+ - V− Soldering Information Infrared or Convection (20 sec.) 235˚C 2000V 200V 5.5V Supply Voltage Supply Voltage
Operating Ratings
Supply Voltage (V+ – V−) Temperature Range Package Thermal Resistance (Note 4) SOT23-6 SOIC-8 MSOP-8 265˚C/W 190˚C/W 235˚C/W 2.7V to 5.0V −40˚C to +125˚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 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
Condition
Min (Note 7)
Typ (Note 6) 0.2 0.2 .001
Max (Note 7) 1.0 50 5
Units mV pA pA dB dB
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
80 80
100 110 −0.3 1.5
V V
V+ – 0.35 6.0 6.0
V+ – 0.1 90 20 15 275 550 700 1400 250
mV mA
µA µA
Output Leakage I @ Shutdown 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
SD = GND, VO = 2.7V SD = GND, VCC = 2.7V Overdrive = 5mV Overdrive = 10mV Overdrive = 50mV 10% to 90% 90% to 10%
0.20 0.20 270 205 120 5 1.7 1.8 6 2
IS LEAKAGE tPD
µA ns ns ns ns µs
tSKEW tr tf ton
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 Parameter Input Offset Voltage Input Bias Current (Note 8) Condition Min (Note 7) Typ (Note 6) 0.2 0.2 Max (Note 7) 1.0 50 Units mV pA
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LMV761/LMV762
5.0V Electrical Characteristics
(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. Parameter 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) 225 450 SD = GND, VO = 5.0V 0.20 0.20 225 190 120 5 10% to 90% 90% to 10% 1.7 1.5 4 ns ns ns µs ns 2 700 1400 µA µA µA 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 40 250 80 80 Condition Min (Note 7) Typ (Note 6) 0.01 100 110 −.3 3.8 Max (Note 7) 5 Units pA dB dB V V mV mA
Symbol IOS CMRR PSRR CMVR VO ISC IS
IOUT
LEAKAGE
Output Leakage I @ Shutdown
IS LEAKAGE tPD
Supply Leakage I @ Shutdown SD = GND, VCC = 5.0V Propagation Delay RL = 5.1kΩ CL = 50pF Propagation Delay Skew Output Rise Time Output Fall Time Turn On Time from Shutdown Overdrive = 5mV Overdrive = 10mV Overdrive = 50mV
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
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LMV761/LMV762
Connection Diagrams
LMV761 Single 6-Pin SOT23 LMV761 Single 8-Pin SOIC LMV762 Dual 8-Pin SOIC & MSOP
20037001
20037002
20037003
Top View
Top View
Top View
Ordering Information
Package 6-Pin SOT23 8-Pin SOIC 8-Pin SOIC 8-Pin MSOP Part Number LMV761MF LMV761MFX LMV761MA LMV761MAX LMV762MA LMV762MAX LMV762MM LMV762MMX C23A LMV762MA LMV761MA Package Marking C22A Transport Media 1k units Tape and Reel 3k units Tape and Reel Rail 2.5k Units Tape and Reel Rail 2.5k Units Tape and Reel 1k Units Tape and Reel 3.5k Units Tape and Reel MUA08A M08A M08A NSC Drawing MF06A
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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
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LMV761/LMV762
Typical Performance Characteristics
Output Voltage vs. Supply Voltage
(Continued) 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
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LMV761/LMV762
Typical Performance Characteristics
ISINK vs. VOUT
(Continued) 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
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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 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 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.
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LMV761/LMV762
Physical Dimensions
unless otherwise noted
inches (millimeters)
6-Pin SOT23 NS Package Number MF06A
8-Pin SOIC NS Package Number M08A
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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
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