LMV7239M5

LMV7235/LMV7239 45 nsec, Ultra Low Power, Low Voltage, Rail-to-Rail Input Comparator with Open-Drain/Push-Pull Output February 2002 LMV7235/LMV7239 45ns, Ultra Low Power, Low Voltage, Rail-to-Rail Input Comparator with Open-Drain/Push-Pull Output General Description The LMV7235/39 are ultra low power, low voltage, 45ns comparators. They are guaranteed to operate over the full supply voltage range of 2.7V to 5V. These devices achieve a 45ns propagation delay while consuming only 65µA of supply current at 5V. The LMV7235/39 have a greater than rail-to-rail common mode voltage range. The input common mode voltage range extends 200mV below ground and 200mV above supply, allowing both ground and supply sensing. The LMV7235 features an open drain output. By connecting an external resistor, the output of the comparator can be used as a level shifter. The LMV7239 features a push-pull output stage. This feature allows operation without the need of an external pull-up resistor. The LMV7235/39 are available in the SC70-5 and SOT23-5 packages, which are ideal for systems where small size and low power is critical. Features (VS = 5V, TA = 25˚C, Typical values unless otherwise specified) n Propagation delay 45ns n Low supply current 65µA n Rail-to-Rail input n Open drain and push-pull output n Ideal for 2.7V and 5V single supply applications n Available in space saving packages: 5-pin SOT23-5 and 5-pin SC70-5 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 Application 10135902 © 2002 National Semiconductor Corporation DS101359 www.national.com LMV7235/LMV7239 Connection Diagram SC70-5/SOT23-5 10135903 Top View Ordering Information Package 5-pin SC70-5 Part Number LMV7235M7 LMV7235M7X LMV7239M7 LMV7239M7X LMV7235M5 5-pin SOT23-5 LMV7235M5X LMV7239M5 LMV7239M5X Marking C21 C21 C20 C20 C21A C21A C20A C20A Supplied as 1k Units Tape and Reel 3k Units Tape and Reel 1k Units Tape and Reel 3k Units Tape and Reel 1k Units Tape and Reel 3k Units Tape and Reel 1k Units Tape and Reel 3k Units Tape and Reel MF05A MAA05A NSC Drawing Simplified Schematic 10135901 www.national.com 2 LMV7235/LMV7239 Absolute Maximum Ratings (Note 1) Voltage at Input/Output Pins Current at Input Pin (Note 9) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. ESD Tolerance (Note 2) Machine Body Human Model Body Differential Input Voltage Output Short Circuit Duration Supply Voltage (V+ - V−) Soldering Information Infrared or Convection (20 sec) Wave Soldering (10 sec) 235˚C 260˚C (lead temp) 100V 1000V (V+) +0.3V (V−) −0.3V ± 10mA Operating Ratings Supply Voltages (V+ - V−) Junction Temperature Range (Note 4) Storage Temperature Range Package Thermal Resistance SC70-5 SOT23-5 478˚C/W 265˚C/W 2.7V to 5V −40˚C to +85˚C −65˚C to +150˚C ± Supply Voltage (Note 3) 5.5V 2.7V Electrical Characteristics Unless otherwise specified, all limits guaranteed for TJ = 25˚C, VCM = V+/2, V+ = 2.7V, V− = 0V−. Boldface limits apply at the temperature extremes. Symbol VOS IB IOS CMRR PSRR VCM Parameter Input Offset Voltage Input Bias Current Input Offset Current Common Mode Rejection Ratio Power Supply Rejection Ratio Input Common-Mode Voltage Range 0V < VCM < 2.7V (Note 7) V+ = 2.7V to 5V CMRR > 50dB Conditions Typ (Note 5) 0.8 30 5 62 85 V+ +0.2 −0.2 VO Output Swing High (LMV7239 only) IL = 4mA, VID = 500mV IL = 0.4mA, VID = 500mV Output Swing Low (LMV7239/LMV7235) IL = −4mA, VID = −500mV IL = −0.4mA, VID = −500mV ISC Output Short Circuit Current Sourcing, VO = 0V (LMV7239 only) (Note 3) Sinking, VO = 2.7V (LMV7235 RL = 10k) (Note 3) IS Supply Current No load V+ −0.26 V+ −0.02 230 15 15 350 450 Limits (Note 6) 6 8 400 600 200 400 52 65 V+ +0.1 V+ −0.1 0 V+ −0.35 Units mV max nA max nA max dB min dB min V min V max V min V min mV max mV max mA 20 52 85 100 mA µA max 3 www.national.com LMV7235/LMV7239 2.7V Electrical Characteristics Symbol tPD Parameter Propagation Delay (Continued) Unless otherwise specified, all limits guaranteed for TJ = 25˚C, VCM = V+/2, V+ = 2.7V, V− = 0V−. Boldface limits apply at the temperature extremes. Conditions Overdrive = 20mV (Note 10) Overdrive = 50mV (Note 10) Overdrive = 100mV (Note 10) Typ (Note 5) 68 63 50 5 1.7 112 Limits (Note 6) Units ns ns ns ns ns ns tSKEW tr Propagation Delay Skew (LMV7239 only) Output Rise Time (Note 8) LMV7239 10% to 90% LMV7235 10% to 90% (Note 10) tf ILEAKAGE Output Fall Time Output Leakage Current (LMV7235 only) 90% to 10% 1.7 3 ns nA 5V Electrical Characteristics Unless otherwise specified, all limits guaranteed for TJ = 25˚C, VCM = V+/2, V+ = 5V, V− = 0V. Boldface limits apply at the temperature extremes. Symbol VOS IB IOS CMRR PSRR VCM Parameter Input Offset Voltage Input Bias Current Input Offset Current Common Mode Rejection Ratio Power Supply Rejection Ratio Input Common-Mode Voltage Range 0V < VCM < 5V V+ = 2.7V to 5V CMRR > 50dB Conditions Typ (Note 5) 1 30 5 67 85 V+ +0.2 −0.2 VO Output Swing High (LMV7239 only) IL = 4mA, VID = 500mV IL = 0.4mA, VID = 500mV Output Swing Low (LMV7239/LMV7235) IL = −4mA, VID = −500mV IL = −0.4mA, VID = −500mV V+ −0.15 V+ −0.01 230 10 350 450 Limits (Note 6) 6 8 400 600 200 400 52 65 V+ +0.1 V+ −0.1 0 V+ −0.25 Units mV max nA max nA max dB min dB min V min V max V min V min mV max mV max www.national.com 4 LMV7235/LMV7239 5V Electrical Characteristics Symbol ISC Parameter Output Short Circuit Current (Continued) Unless otherwise specified, all limits guaranteed for TJ = 25˚C, VCM = V+/2, V+ = 5V, V− = 0V. Boldface limits apply at the temperature extremes. Conditions Sourcing, VO = 0V (LMV7239 only) (Note 3) Sinking, VO = 5V (LMV7235 RL = 10k) (Note 3) Typ (Note 5) 55 Limits (Note 6) 25 15 30 20 95 110 Units mA min mA min µA max ns max ns max ns max ns ns ns 60 IS tPD Supply Current Propagation Delay No load Overdrive = 20mV (Note 10) Overdrive = 50mV (Note 10) Overdrive = 100mV (Note 10) 65 62 57 45 5 1.2 100 tSKEW tr Propagation Delay Skew (LMV7239 only) Output Rise Time (Note 8) LMV7239 10% to 90% LMV7235 10% to 90% (Note 10) tf ILEAKAGE Output Fall Time Output Leakeage Current (LMV7235 only) 90% to 10% 1.2 3 ns nA 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, 1.5kΩ in series with 100pF. Machine model, 200pF. 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 150˚C. Output currents in excess of ± 30mA over long term may adversely affect reliability. 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: Typical Values represent the most likely parametric norm. Note 6: All limits are guaranteed by testing or statistical analysis. Note 7: CMRR is not linear over the common mode range. Limits are guaranteed over the worst case from 0 to VCC/2 or VCC/2 to VCC. Note 8: Propagation Delay Skew is defined as the absolute value of the difference between tPDLH and tPDHL. Note 9: Limiting input pin current is only necessary for input voltages that exceed absolute maximum input voltage ratings. Note 10: A 10k pull-up resistor was used when measuring the LMV7235. The rise time of the LMV7235 is a function of the R-C time constant. 5 www.national.com LMV7235/LMV7239 Typical Performance Characteristics Supply Current vs. Supply Voltage (Unless otherwise specified, VS = 5V, CL = 10pF, TA = 25˚C). Sourcing Current vs. Output Voltage 10135904 10135905 Sourcing Current vs. Output Voltage Sinking Current vs. Output Voltage 10135906 10135907 Sinking Current vs. Output Voltage Input Bias Current vs. Input Voltage 10135909 10135908 www.national.com 6 LMV7235/LMV7239 Typical Performance Characteristics 25˚C). (Continued) Input Bias Current vs. Input Voltage (Unless otherwise specified, VS = 5V, CL = 10pF, TA = Propagation Delay vs. Temperature 10135910 10135911 Propagation Delay vs. Capacitive Load Propagation Delay vs. Capacitive Load 10135912 10135913 Propagation Delay vs. Input Overdrive Propagation Delay vs. Input Overdrive 10135914 10135915 7 www.national.com LMV7235/LMV7239 Typical Performance Characteristics 25˚C). (Continued) Propagation Delay vs. Common Mode Voltage (Unless otherwise specified, VS = 5V, CL = 10pF, TA = Propagation Delay vs. Common Mode Voltage 10135916 10135917 Application Section The LMV7235/LMV7239 are single supply comparators with 45ns of propagation delay and only 65µA of supply current. The LMV7235/LMV7239 are rail-to-rail input and output. The typical input common mode voltage range of −0.2V below the ground to 0.2V above the supply. The LMV7235/39 use a complimentary PNP and NPN input stage in which the PNP stage senses common mode voltage near V− and the NPN stage senses common mode voltage near V+. If either of the input signals falls below the negative common mode limit, the parasitic PN junction formed by the substrate and the base of the PNP will turn on resulting in an increase of input bias current. If one of the input goes above the positive common mode limit, the output will still maintain the correct logic level as long as the other input stays within the common mode range. However, the propagation delay will increase. When both inputs are outside the common mode voltage range, current saturation occurs in the input stage, and the output becomes unpredictable. The propagation delay does not increase significantly with large differential input voltages. However, large differential voltages greater than the supply voltage should be avoided to prevent damage to the input stage. The LMV7239 has a push-pull output. When the output switches, there is a direct path between VCC and ground, causing high output sinking or sourcing current during the transition. After the transition, the output current decreases and the supply current settles back to about 65µA at 5V, thus conserving power consumption. The LMV7235 has an open drain that requires a pull-up resistor to a positive supply voltage for the output to switch properly. When the internal output transistor is off, the output voltage will be pulled up to the external positive voltage. Comparator with Hysteresis The basic comparator configuration may oscillate or produce a noisy output if the applied differential input voltage is near the comparator’s offset voltage. This usually happens when the input signal is moving very slowly across the comparator’s switching threshold. This problem can be prevented by the addition of hysteresis or positive feedback. Inverting Comparator with Hysteresis The inverting comparator with hysteresis requires a three resistor network that is referenced to the supply voltage VCC of the comparator. When VIN at the inverting input is less than VA, the voltage at the non-inverting node of the comparator (VIN < VA), the output voltage is high (for simplicity assume VO switches as high as VCC). The three network resistors can be represented as R1//R3 in series with R2. The lower input trip voltage VA1 is defined as VA1 = VCCR2 / ((R1//R3) + R2) When VIN is greater than VA (VIN > VA), the output voltage is low, very close to ground. In this case the three network resistors can be presented as R2//R3 in series with R1. The upper trip voltage VA2 is defined as VA2 = VCC (R2//R3) / ((R1+ (R2//R3) The total hysteresis provided by the network is defined as Delta VA = VA1- VA2 To assure that the comparator will always switch fully to VCC and not be pulled down by the load the resistors, values should be chosen as follow: RPULL-UP