LMV7235M7

LMV7235/LMV7239 45 nsec, Ultra Low Power, Low Voltage, Rail-to-Rail Input Comparator with Open-Drain/Push-Pull Output August 2006 LMV7235/LMV7239 45 nsec, Ultra Low Power, Low Voltage, Rail-to-Rail Input Comparator with Open-Drain/Push-Pull Output General Description The LMV7235/LMV7239 are ultra low power, low voltage, 45 nsec comparators. They are guaranteed to operate over the full supply voltage range of 2.7V to 5V. These devices achieve a 45 nsec propagation delay while consuming only 65µA of supply current at 5V. The LMV7235/LMV7239 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/LMV7239 are available in the 5-Pin SC70 and 5-Pin SOT23 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 45 nsec 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-pin SC70 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 Crystal Oscillator © 2006 National Semiconductor Corporation DS101359 www.national.com LMV7235/LMV7239 Connection Diagram 5-Pin SC70/SOT23 10135903 Top View Ordering Information Package Part Number LMV7235M7 5-pin SC70 LMV7235M7X LMV7239M7 LMV7239M7X LMV7235M5 5-pin SOT23 LMV7235M5X LMV7239M5 LMV7239M5X Marking C21 C20 C21A 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) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. ESD Tolerance (Note 2) Human Model Body Machine Body Differential Input Voltage Output Short Circuit Duration Supply Voltage (V+ - V−) Soldering Information Infrared or Convection (20 sec) 235˚C 1000V 100V Wave Soldering (10 sec) Voltage at Input/Output Pins Current at Input Pin (Note 9) + 260˚C (lead temp) (V ) +0.3V, (V−) −0.3V ± 10mA Operating Ratings Supply Voltages (V+ - V−) Temperature Range (Note 4) Storage Temperature Range Package Thermal Resistance 5-Pin SC70 5-Pin SOT23 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 TA = 25˚C, VCM = V+/2, V+ = 2.7V, V− = 0V−. Boldface limits apply at the temperature extremes. Symbol VOS IB IOS CMRR PSRR VCM VO Parameter Input Offset Voltage Input Bias Current Input Offset Current Common Mode Rejection Ratio Power Supply Rejection Ratio 0V < VCM < 2.7V (Note 7) V+ = 2.7V to 5V − Conditions Min (Note 6) Typ (Note 5) 0.8 30 5 Max (Note 6) 6 8 400 600 200 400 Units mV nA nA dB dB 52 65 V −0.1 V− V+ −0.35 62 85 −0.2 to 2.9 V+ −0.26 V+ −0.02 230 15 15 350 450 V +0.1 V+ + Input Common-Mode Voltage Range CMRR > 50dB 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 V V mV mV mA ISC Output Short Circuit Current Sourcing, VO = 0V (LMV7239 only) (Note 3) Sinking, VO = 2.7V (LMV7235 RL = 10k) (Note 3) 20 52 68 63 50 5 85 100 mA IS tPD Supply Current Propagation Delay No load Overdrive = 20mV (Note 10) Overdrive = 50mV (Note 10) Overdrive = 100mV (Note 10) µA ns ns ns ns tSKEW Propagation Delay Skew (LMV7239 only) (Note 8) 3 www.national.com LMV7235/LMV7239 2.7V Electrical Characteristics Symbol tr Parameter Output Rise Time (Continued) Unless otherwise specified, all limits guaranteed for TA = 25˚C, VCM = V+/2, V+ = 2.7V, V− = 0V−. Boldface limits apply at the temperature extremes. Conditions LMV7239 10% to 90% LMV7235 10% to 90% (Note 10) Min (Note 6) Typ (Note 5) 1.7 112 Max (Note 6) Units ns ns tf Output Fall Time 90% to 10% 1.7 3 ns nA ILEAKAGE Output Leakage Current (LMV7235 only) 5V Electrical Characteristics Unless otherwise specified, all limits guaranteed for TA = 25˚C, VCM = V+/2, V+ = 5V, V− = 0V. Boldface limits apply at the temperature extremes. Symbol VOS IB IOS CMRR PSRR VCM VO Parameter Input Offset Voltage Input Bias Current Input Offset Current Common Mode Rejection Ratio Power Supply Rejection Ratio Input Common-Mode Voltage Range Output Swing High (LMV7239 only) 0V < VCM < 5V V+ = 2.7V to 5V CMRR > 50dB 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 = 5V (LMV7235 RL = 10k) (Note 3) IS tPD Supply Current Propagation Delay No load Overdrive = 20mV (Note 10) Overdrive = 50mV (Note 10) Overdrive = 100mV (Note 10) tSKEW Propagation Delay Skew (LMV7239 only) (Note 8) 25 15 30 20 52 65 V− −0.1 V− V+ −0.25 Conditions Min (Note 6) Typ (Note 5) 1 30 5 67 85 −0.2 to 5.2 V+ −0.15 V+ −0.01 230 10 55 mA 60 mA 65 62 57 45 5 95 110 350 450 V+ +0.1 V+ Limits (Note 6) 6 8 400 600 200 400 Units mV nA nA dB dB V V V mV mV µA ns ns ns ns www.national.com 4 LMV7235/LMV7239 5V Electrical Characteristics Symbol tr Parameter Output Rise Time (Continued) Unless otherwise specified, all limits guaranteed for TA = 25˚C, VCM = V+/2, V+ = 5V, V− = 0V. Boldface limits apply at the temperature extremes. Conditions LMV7239 10% to 90% LMV7235 10% to 90% (Note 10) Min (Note 6) Typ (Note 5) 1.2 100 Limits (Note 6) Units ns ns tf Output Fall Time 90% to 10% 1.2 3 ns nA ILEAKAGE Output Leakeage Current (LMV7235 only) 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, applicable std. MIL-STD-883, Method 3015.7. Machine Model, applicable std. JESD22-A115-A (ESD MM std. of JEDEC) Field-Induced Charge-Device Model, applicable std. JESD22-C101-C (ESD FICDM std. of JEDEC). 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. The maximum allowable power dissipation at any ambient temperature is PD = (TJ(MAX) – TA)/ θJA. All numbers apply for packages soldered directly onto a PC Board. Note 5: Typical values represent the most likely parametric norm as determined at the time of characterization. Actual typical values may vary over time and will also depend on the application and configuration. The typical values are not tested and are not guaranteed on shipped production material. 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 (Unless otherwise specified, VS = 5V, CL = 10pF, TA = 25˚C). (Continued) Input Bias Current vs. Input Voltage 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 (Unless otherwise specified, VS = 5V, CL = 10pF, TA = 25˚C). (Continued) Propagation Delay vs. Common Mode Voltage Propagation Delay vs. Common Mode Voltage 10135916 10135917 www.national.com 8 LMV7235/LMV7239 Application Information 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/ LMV7239 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, as shown in Figure 1. When VIN at the inverting input is less than VA, the voltage at the noninverting 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