75 nsec, Ultra Low Power, Low Voltage, Rail-to-Rail Input Comparator with Open-Drain/Push-Pull Output General Description Features The LMV7235/LMV7239/LMV7239Q are ultra low power, low voltage, 75 nsec comparators. They are guaranteed to operate over the full supply voltage range of 2.7V to 5.5V. These devices achieve a 75 nsec propagation delay while consuming only 65A of supply current at 5V. The LMV7235/LMV7239/LMV7239Q have a greater than railto-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/LMV7239Q features a push-pull output stage. This feature allows operation without the need of an external pull-up resistor. The LMV7235/LMV7239/LMV7239Q are available in the 5Pin SC70 and 5-Pin SOT23 packages, which are ideal for systems where small size and low power is critical. (VS = 5V, TA = 25C Typical values unless otherwise specified) 75 nsec Propagation delay 65A Low supply current Rail-to-Rail input Open drain and push-pull output Ideal for 2.7V and 5V single supply applications Available in space saving packages -- 5-pin SOT23 -- 5-pin SC70 LMV7239Q is an automotive grade product that is AECQ grade 1 qualified and is manufactured on an automotive grade flow. Applications Portable and battery powered systems Scanners Set top boxes High speed differential line receiver Window comparators Zero-crossing detectors High speed sampling circuits Automotive Typical Application 10135902 Crystal Oscillator (c) 2012 Texas Instruments Incorporated 101359 SNOS532K www.ti.com LMV7235/LMV7239/LMV7239Q 45 nsec, Ultra Low Power, Low Voltage, Rail-to-Rail Input Comparator with Open-Drain/Push-Pull Output January 6, 2012 LMV7235/LMV7239/ LMV7239Q LMV7235/LMV7239/LMV7239Q Connection Diagram 5-Pin SC70/SOT23 10135903 Top View Ordering Information Package Part Number LMV7235M7 LMV7235M7X 5-pin SC70 LMV7239M7 LMV7239M7X LMV7239QM7 LMV7239QM7X LMV7235M5 5-pin SOT23 LMV7235M5X LMV7239M5 LMV7239M5X Marking C21 C20 C42 C21A C20A Supplied as NSC Drawing 1k Units Tape and Reel 3k Units Tape and Reel 1k Units Tape and Reel 3k Units Tape and Reel MAA05A 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 MF05A 3k Units Tape and Reel * Automotive Grade (Q) product incorporates enhanced manufacturing and support processes for the automotive market, including defect detection methodologies. Reliability qualification is compliant with the requirements and temperature defined in the AECQ100 standard. Automotive grade products are defined with the letter Q. For more information, go to http://www.national.com/ automotive. www.ti.com 2 LMV7235/LMV7239/LMV7239Q 10135901 Simplified Schematic 3 www.ti.com LMV7235/LMV7239/LMV7239Q Voltage at Input/Output Pins Current at Input Pin (Note 9) Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the Texas Instruments 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) Wave Soldering (10 sec) (V+) +0.3V, (V-) -0.3V 10mA Operating Ratings Supply Voltages (V+ - V-) Temperature Range (Note 4) LMV7235/LMV7239 LMV7239Q Storage Temperature Range Package Thermal Resistance 5-Pin SC70 5-Pin SOT23 1000V 100V Supply Voltage (Note 3) 6V 235C 260C (lead temp) 2.7V to 5.5V -40C to +85C -40C to +125C -65C to +150C 478C/W 265C/W 2.7V Electrical Characteristics Unless otherwise specified, all limits guaranteed for TA = 25C, VCM = V+/2, V+ = 2.7V, V- = 0V-. Boldface limits apply at the temperature extremes. Symbol Parameter Conditions VOS Input Offset Voltage IB Input Bias Current IOS Input Offset Current CMRR Common Mode Rejection Ratio 0V < VCM < 2.7V (Note 7) PSRR Power Supply Rejection Ratio V+ = 2.7V to 5V VCM Input Common-Mode Voltage Range Output Swing High (LMV7239 only) VO Output Swing Low (LMV7235/LMV7239/LMV7239Q) ISC IS tPD www.ti.com Output Short Circuit Current Supply Current Propagation Delay Min (Note 6) Units 0.8 6 8 mV 30 400 600 nA 5 200 400 nA 62 65 85 CMRR > 50dB IL = 4mA, VID = 500mV V+ -0.35 IL = -4mA, VID = -500mV Max (Note 6) 52 V- IL = 0.4mA, VID = 500mV Typ (Note 5) -0.1V- -0.2 to 2.9 dB dB V+ +0.1V+ V V+ -0.26 V V+ -0.02 V 230 350 450 mV IL = -0.4mA, VID = -500mV 15 mV Sourcing, VO = 0V (LMV7239 only) (Note 3) 15 mA Sinking, VO = 2.7V (LMV7235, RL = 10k) (Note 3) 20 mA 52 No load 85 100 A Overdrive = 20mV CLOAD = 15pF (Note 10) 96 ns Overdrive = 50mV CLOAD = 15pF (Note 10) 87 ns Overdrive = 100mV CLOAD = 15pF (Note 10) 85 ns 4 tSKEW tr Parameter Conditions Propagation Delay Skew (LMV7239 only) Overdrive = 20mV (Note 8) Output Rise Time tf Output Fall Time ILEAKAGE Output Leakage Current (LMV7235 only) Min (Note 6) Typ (Note 5) Max (Note 6) Units 2 ns LMV7239/LMV7239Q 10% to 90% 1.7 ns LMV7235 10% to 90% (Note 10) 112 ns 90% to 10% 1.7 ns 3 nA 5V Electrical Characteristics Unless otherwise specified, all limits guaranteed for TA = 25C, VCM = V+/2, V+ = 5V, V- = 0V. Boldface limits apply at the temperature extremes. Symbol Parameter Conditions Min (Note 6) Typ (Note 5) Limits (Note 6) Units 1 6 8 mV 30 400 600 nA 5 200 400 nA VOS Input Offset Voltage IB Input Bias Current IOS Input Offset Current CMRR Common Mode Rejection Ratio 0V < VCM < 5V 52 67 Power Supply Rejection Ratio V+ = 2.7V to 5V 65 85 PSRR VCM Input Common-Mode Voltage Range Output Swing High (LMV7239 only) VO Output Swing Low (LMV7235/LMV7239/LMV7239Q) ISC IS tPD tSKEW Output Short Circuit Current Supply Current Propagation Delay Propagation Delay Skew (LMV7239 only) CMRR > 50dB V- -0.1V- IL = 4mA, VID = 500mV V+ -0.25 IL = 0.4mA, VID = 500mV -0.2 to 5.2 dB V+ +0.1V+ V V+ -0.15 V V+ -0.01 V IL = -4mA, VID = -500mV 230 IL = -0.4mA, VID = -500mV 10 Sourcing, VO = 0V (LMV7239 only) (Note 3) 25 15 55 Sinking, VO = 5V (LMV7235, RL = 10k) (Note 3) 30 20 60 350 450 mV mV mA mA 65 No load dB 95 110 A Overdrive = 20mV CLOAD = 15pF (Note 10) 89 ns Overdrive = 50mV CLOAD = 15pF (Note 10) 82 ns Overdrive = 100mV CLOAD = 15pF (Note 10) 75 ns Overdrive = 20mV (Note 8) 1 ns 5 www.ti.com LMV7235/LMV7239/LMV7239Q Symbol LMV7235/LMV7239/LMV7239Q Symbol tr Parameter Output Rise Time tf Output Fall Time ILEAKAGE Output Leakeage Current (LMV7235 only) Conditions Min (Note 6) Typ (Note 5) Limits (Note 6) Units LMV7239 10% to 90% 1.2 ns LMV7235 10% to 90% (Note 10) 100 ns 90% to 10% 1.2 ns 3 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, 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 150C. 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), JA. The maximum allowable power dissipation at any ambient temperature is PD = (TJ(MAX) - TA) / JA. 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. www.ti.com 6 (Unless otherwise specified, VS = 5V, CL = 10pF, TA = 25C). Supply Current vs. Supply Voltage SUPPLY CURRENT (A) 120 Sourcing Current vs. Output Voltage -40C 25C 85C 125C 100 80 60 40 20 0 0 1 2 3 4 SUPPLY VOLTAGE (V) 5 10135925 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 7 www.ti.com LMV7235/LMV7239/LMV7239Q Typical Performance Characteristics LMV7235/LMV7239/LMV7239Q Input Bias Current vs. Input Voltage Propagation Delay vs. Temperature PROPAGATION DELAY (ns) 160 VS=2.7V VOD=20mV CLOAD=15pF 150 140 130 Falling Edge 120 110 100 90 Rising Edge 80 -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (C) 10135926 10135910 Propagation Delay vs. Temperature Propagation Delay vs. Capacitive Load 106 VS=5V VOD=20mV CLOAD=15pF 130 PROPAGATION DELAY (ns) PROPAGATION DELAY (ns) 140 120 Falling Edge 110 100 90 Rising Edge 80 VS= 2.7V VOD=20mV 104 102 Falling Edge 100 98 96 Rising Edge 94 -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (C) 0 20 40 60 80 CAPACITANCE (pF) 100 10135927 10135928 Propagation Delay vs. Capacitive Load Propagation Delay vs. Input Overdrive 100 VS= 5V VOD=20mV PROPAGATION DELAY (ns) PROPAGATION DELAY (ns) 96 94 Falling Edge 92 90 VS= 2.7V CLOAD=15pF 95 Rising Edge 90 85 Rising Edge 88 0 20 40 60 80 CAPACITANCE (pF) 100 20 10135929 www.ti.com Falling Edge 80 30 40 50 60 70 80 90 100 INPUT OVERDRIVE (mV) 10135930 8 Propagation Delay vs. Common Mode Voltage 120 VS= 5V CLOAD=15pF 85 PROPAGATION DELAY (ns) PROPAGATION DELAY (ns) 90 Rising Edge 80 75 LMV7235/LMV7239/LMV7239Q Propagation Delay vs. Input Overdrive Falling Edge 70 VS= 2.7V VOD=20mV CLOAD=15pF 115 110 105 100 95 90 85 Rising Edge Falling Edge 80 20 40 60 80 INPUT OVERDRIVE (mV) 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 INPUT COMMON MODE VOLTAGE (V) 10135931 10135932 Propagation Delay vs. Common Mode Voltage PROPAGATION DELAY (ns) 110 100 90 VS= 5V VOD=20mV CLOAD=15pF Falling Edge Rising Edge 80 0 1 2 3 4 5 INPUT COMMON MODE VOLTAGE (V) 10135933 9 www.ti.com LMV7235/LMV7239/LMV7239Q Application Information The LMV7235/LMV7239/LMV7239Qare single supply comparators with 75ns of propagation delay and only 65A of supply current. The LMV7235/LMV7239/LMV7239Qare 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/LMV7239Quse 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 65A 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. www.ti.com 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 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 << RLOAD 10 LMV7235/LMV7239/LMV7239Q 10135919 FIGURE 1. Inverting Comparator with Hysteresis VIN2 = [VREF (R1+ R2) - VCC R1] / R2 NON-INVERTING COMPARATOR WITH HYSTERESIS A non inverting comparator with hysteresis requires a two resistor network, and a voltage reference (VREF) at the inverting input. When V IN is low, the output is also low. For the output to switch from low to high, VIN must rise up to VIN1 where VIN1 is calculated by. The hysteresis of this circuit is the difference between VIN1 and VIN2. Delta VIN = VCC R1 / R2 VIN1 = R1*(VREF / R2) + VREF When VIN is high, the output is also high, to make the comparator switch back to it's low state, VIN must equal VREF before VA will again equal VREF. VIN can be calculated by 11 www.ti.com LMV7235/LMV7239/LMV7239Q 10135924 10135920 FIGURE 2. Non-Inverting Comparator with Hysteresis www.ti.com 12 ZERO-CROSSING DETECTOR The inverting input is connected to ground and the non-inverting input is connected to 100mVp-p signal. As the signal at the non-inverting input crosses 0V, the comparator's output changes state. 10135922 FIGURE 5. Crystal Oscillator IR RECEIVER The LMV7239 is an ideal candidate to be used as an infrared receiver. The infrared photo diode creates a current relative to the amount of infrared light present. The current creates a voltage across RD. When this voltage level cross the voltage applied by the voltage divider to the inverting input, the output transitions. 10135918 FIGURE 3. Zero-Crossing Detector THRESHOLD DETECTOR Instead of tying the inverting input to 0V, the inverting input can be tied to a reference voltage. The non-inverting input is connected to the input. As the input passes the VREF threshold, the comparator's output changes state. 10135923 FIGURE 6. IR Receiver 10135921 FIGURE 4. Threshold Detector 13 www.ti.com LMV7235/LMV7239/LMV7239Q CRYSTAL OSCILLATOR A simple crystal oscillator using the LMV7239 is shown below. Resistors R1 and R2 set the bias point at the comparator's non-inverting input. Resistors R3, R4 and C1 sets the inverting input node at an appropriate DC average level based on the output. The crystal's path provides resonant positive feedback and stable oscillation occurs. The output duty cycle for this circuit is roughly 50%, but it is affected by resistor tolerances and to a lesser extent by the comparator offset. CIRCUIT LAYOUT AND BYPASSING The LMV7235/LMV7239/LMV7239Qrequire high speed layout. Follow these layout guidelines: 1. Use printed circuit board with a good, unbroken low-inductance ground plane. 2. Place a decoupling capacitor (0.1F ceramic surface mount capacitor) as close as possible to VCC pin. 3. On the inputs and the output, keep lead lengths as short as possible to avoid unwanted parasitic feedback around the comparator. Keep inputs away from output. 4. Solder the device directly to the printed circuit board rather than using a socket. 5. For slow moving input signals, take care to prevent parasitic feedback. A small capacitor (1000pF or less) placed between the inputs can help eliminate oscillations in the transition region. This capacitor causes some degradation to tPD when the source impedance is low. 6. The topside ground plane runs between the output and inputs. 7. Ground trace from the ground pin runs under the device up to the bypass capacitor, shielding the inputs from the outputs. LMV7235/LMV7239/LMV7239Q Physical Dimensions inches (millimeters) unless otherwise noted 5-Pin SC70 NS Package Number MAA05A 5-Pin SOT23 NS Package Number MF05A www.ti.com 14 www.ti.com 15 LMV7235/LMV7239/LMV7239Q Notes LMV7235/LMV7239/LMV7239Q 45 nsec, Ultra Low Power, Low Voltage, Rail-to-Rail Input Comparator with Open-Drain/Push-Pull Output Notes www.ti.com IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI's terms and conditions of sale supplied at the time of order acknowledgment. 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