LMV722LDX

LMV721/LMV72210MHz, Low Noise, Low Voltage, and Low Power Operational Amplifier August 1999 LMV721/LMV722 10MHz, Low Noise, Low Voltage, and Low Power Operational Amplifier General Description The LMV721 (Single) and LMV722 (Dual) are low noise, low voltage, and low power op amps, that can be designed into a wide range of applications. The LMV721/LMV722 has a unity gain bandwidth of 10MHz, a slew rate of 5V/us, and a quiescent current of 930uA/amplifier at 2.2V. The LMV721/722 are designed to provide optimal performance in low voltage and low noise systems. They provide rail-to-rail output swing into heavy loads. The input common-mode voltage range includes ground, and the maximum input offset voltage are 3.5mV (Over Temp.) for the LMV721/LMV722. Their capacitive load capability is also good at low supply voltages. The operating range is from 2.2V to 5.5V. The chip is built with National’s advanced Submicron Silicon-Gate BiCMOS process. The single version, LMV721, is available in 5 pin SOT23-5 and a SC-70 (new) package. The dual version, LMV722, is available in a SO-8 and MSOP-8 package. Features (For Typical, 5 V Supply Values; Unless Otherwise Noted) n Guaranteed 2.2V and 5.0V Performance n Low Supply Current LMV721/2 930µA/amplifier @2.2V n High Unity-Gain Bandwidth 10MHz n Rail-to-Rail Output Swing @ 600Ω load 120mV from either rail at 2.2V @ 2kΩ load 50mV from either rail at 2.2V n Input Common Mode Voltage Range Includes Ground n Silicon Dust™, SC70-5 Package 2.0x2.0x1.0 mm @ f = 1KHz n Input Voltage Noise 9 Applications n n n n Cellular an Cordless Phones Active Filter and Buffers Laptops and PDAs Battery Powered Electronics Connection Diagrams 5-Pin SC-70/SOT23-5 8-Pin SO/MSOP DS100922-99 DS100922-63 Top View Top View Silicon Dust™ is a trademark of National Semiconductor Corporation. © 1999 National Semiconductor Corporation DS100922 www.national.com Ordering Information Temperature Range Package 8-Pin Small Outline Industrial −40˚C to +85˚C LMV722M LMV722MX 8-pin MSOP LMV722MM LMV722MMX 5-Pin SOT23 LMV721M5 LMV721M5X 5-Pin SC-70 LMV721M7 LMV721M7X LMV722M LMV722M LMV722 LMV722 A30A A30A A20 A20 Rails 2.5K Units Tape and Reel 1K Units Tape and Reel 3.5K Units Tape and Reel 1K Units Tape and Reel 3K Units Tape and Reel 1K Units Tape and Reel 3K Units Tape and Reel M08A Packaging Marking Transport Media NSC Drawing MUA08A M05B MAA05A www.national.com 2 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 Differential Input Voltage Supply Voltage (V+ – V−) Soldering Information Infrared or Convection (20 sec.) Storage Temp. Range Junction Temperature (Note 4) 235˚C −65˚C to 150˚C 150˚C 2000V 200V Operating Ratings (Note 3) Supply Voltage Temperature Range Thermal Resistance (θJA) Silicon Dust SC70-5 Pkg Tiny SOT23-5 Pkg SO Pkg, 8-pin Surface Mount MSOP Pkg, 8-Pin Mini Surface Mount SO Pkge, 14-Pin Surface Mount 440 ˚C/W 265 ˚C/W 190 ˚C/W 235 ˚C/W 145 ˚C/W 2.2V to 5.0V −40˚C ≤T J ≤85˚C ± Supply Voltage 5.5V 2.2V DC Electrical Characteristics Unless otherwise specified, all limits guaranteed for TJ = 25˚C. V+ = 2.2V, V− = 0V, VCM = V+/2, VO = V+/2 and R Boldface limits apply at the temperature extremes. Symbol VOS TCVOS IB IOS CMRR PSRR VCM AV Parameter Input Offset Voltage Input Offset Voltage Average Drift Input Bias Current Input Offset Current Common Mode Rejection Ratio Power Supply Rejection Ratio Input Common-Mode Voltage Range Large Signal Voltage Gain 0V ≤ VCM ≤ 1.3V 2.2V ≤ V+ ≤ 5V, VO = 0 VCM = 0 For CMRR ≥ 50dB RL=600Ω VO = 0.75V to 2.00V RL= 2kΩ VO = 0.50V to 2.10V VO Output Swing RL = 600Ω to V+/2 Condition Typ (Note 5) 0.02 0.6 260 25 88 90 −0.30 1.3 81 84 2.125 0.061 RL= 2kΩ to V+/2 2.177 0.026 IO Output Current Sourcing, VO = 0V VIN(diff) = ± 0.5V Sinking, VO = 2.2V VIN(diff) = ± 0.5V IS Supply Current LMV721 LMV722 14.9 23.8 0.93 1.64 75 60 75 60 2.090 2.065 0.110 0.135 2.150 2.125 0.050 0.075 10.0 5.0 15.0 5.0 1.2 1.5 2.2 2.6 70 64 70 64 Limit (Note 6) 3 3.5 L > 1 MΩ. Units mV max µV/˚C nA nA dB min dB min V V dB min dB min V min V max V min V max mA min mA min mA max 3 www.national.com 2.2V AC Electrical Characteristics Unless otherwise specified, all limits guaranteed for TJ = 25˚C. V+ = 2.2V, V− = 0V, VCM = V+/2, VO = V+/2 and R L > 1 MΩ. Boldface limits apply at the temperature extremes. Symbol SR GBW Φm Gm en in THD Slew Rate Gain-Bandwdth Product Phase Margin Gain Margin Input-Referred Voltage Noise Input-Referred Current Noise Total Harmonic Distortion f = 1 kHz f = 1 kHz f = 1 kHz AV = 1 RL = 600Ω, VO = 500 mVPP Parameter (Note 7) Conditions Typ (Note 5) 4.9 10 67.4 −9.8 9 0.3 Units V/µs MHz Deg dB 0.004 % 5V DC Electrical Characteristics Unless otherwise specified, all limits guaranteed for TJ = 25˚C. V+ = 5V, V− = 0V, VCM = V+/2, VO = V+/2 and RL > 1 MΩ. Boldface limits apply at the temperature extremes. Symbol VOS TCVOS IB IOS CMRR PSRR VCM AV Parameter Input Offset Voltage Input Offset Voltage Average Drift Input Bias Current Input Offset Current Common Mode Rejection Ratio Power Supply Rejection Ratio Input Common-Mode Voltage Range Large Signal Voltage Gain 0V ≤ VCM ≤ 4.1V 2.2V ≤ V+ ≤ 5.0V, VO = 0 VCM = 0 For CMRR ≥ 50dB RL = 600Ω VO = 0.75V to 4.80V RL = 2kΩ, VO = 0.70V to 4.90V, VO Output Swing RL= 600Ω to V+/2 Condition Typ (Note 5) −0.08 0.6 260 25 89 90 −0.30 4.1 87 94 4.882 0.105 RL = 2kΩ to V+/2 4.962 0.046 IO Output Current Sourcing, V O = 0V VIN(diff) = ± 0.5V Sinking, VO = 5V VIN(diff) = ± 0.5V IS Supply Current LMV721 LMV722 52.6 23.7 1.03 1.83 80 70 85 70 4.840 4.140 0.160 0.185 4.940 4.915 0.080 0.105 25.0 12.0 15.0 8.5 1.4 1.7 2.4 2.8 70 64 70 64 Limit (Note 6) 3 3.5 Units mV max µV/˚C nA nA dB min dB min V V dB min dB min V min V max V min V max mA min mA min mA max www.national.com 4 5V AC Electrical Characteristics Unless otherwise specified, all limits guaranteed for TJ = 25˚C. V+ = 5V, V− = 0V, VCM = V+/2, VO = V+/2 and R Boldface limits apply at the temperature extremes. Symbol SR GBW Φm Gm en in THD Slew Rate Gain-Bandwdth Product Phase Margin Gain Margin Input-Related Voltage Noise Input-Referred Current Noise Total Harmonic Distortion f = 1 kHz f = 1 kHz f = 1kHz, AV = 1 RL = 600Ω, VO = 1 VPP Parameter (Note 7) Conditions Typ (Note 5) 5.25 10.0 72 −11 8.5 0.2 L > 1 MΩ. Units V/µs min MHz Deg dB 0.001 % 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, 1.5 kΩ in series with 100 pF. Machine model, 200Ω in series with 100 pF. 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 30 mA 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 P D = (TJ(max)–T A)/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: Connected as voltage follower with 1V step input. Number specified is the slower of the positive and negative slew rate. 5 www.national.com Typical Performance characteristics Supply Current vs. Supply Voltage(LMV721) Sourcing Current vs. Output Voltage (VS = 2.2V) Sourcing Current vs. Output Voltage (VS = 5V) DS100922-1 DS100922-2 DS100922-3 Sinking Current vs. Output Voltage (VS = 2.2V) Sinking Current vs. Output Voltage (VS = 5V) Output Voltage Swing vs. Supply Voltage(RL = 600Ω) DS100922-4 DS100922-5 DS100922-6 Output Voltage Swing vs. Suppy Voltage (RL = 2kΩ) Input Offset Voltage vs. Input Common-Mode Voltage Range VS = 2.2V Input Offset Voltage vs. Input Common-Mode Voltage Range VS = 5V DS100922-7 DS100922-8 DS100922-9 www.national.com 6 Typical Performance characteristics Input Offset Voltage vs. Supply Voltage(VCM = V+/2) (Continued) Input Voltage vs. Output Voltage (VS = 2.2V, RL = 2kΩ) Input Voltage vs. Output Voltage (VS = 5V, RL = 2kΩ)) DS100922-10 DS100922-11 DS100922-12 Input Voltage Noise vs. Frequency Input Current Noise vs. Frequency +PSRR vs. Frequency DS100922-38 DS100922-32 DS100922-13 −PSRR vs. Frequency CMRR vs. Frequency Gain and Phase Margin vs. Frequency (VS = 2.2V, RL 600Ω) DS100922-14 DS100922-45 DS100922-15 7 www.national.com Typical Performance characteristics Gain and Phase Margin vs. Frequency (VS = 5V, RL 600Ω) (Continued) Slew Rate vs. Supply Voltage THD vs. Frequency DS100922-16 DS100922-17 DS100922-42 Application Notes 1.0 Benefits of the LMV721/722 Size. The small footprints of the LMV721/722 packages save space on printed circuit boards, and enable the design of smaller electronic products, such as cellular phones, pagers, or other portable systems. The low profile of the LMV721/722 make them possible to use in PCMCIA type III cards. Signal Integrity. Signals can pick up noise between the signal source and the amplifier. By using a physically smaller amplifier package, the LMV721/722 can be placed closer to the signal source, reducing noise pickup and increasing signal integrity. Simplified Board Layout. These products help you to avoid using long pc traces in your pc board layout. This means that no additional components, such as capacitors and resistors, are needed to filter out the unwanted signals due to the interference between the long pc traces. Low Supply Current. These devices will help you to maximize battery life. They are ideal for battery powered systems. Low Supply Voltage. National provides guaranteed performance at 2.2V and 5V. These guarantees ensure operation throughout the battery lifetime. Rail-to-Rail Output. Rail-to-rail output swing provides maximum possible dynamic range at the output. This is particularly important when operating on low supply voltages. Input Includes Ground. Allows direct sensing near GND in single supply operation. Protection should be provided to prevent the input voltages from going negative more than −0.3V (at 25˚C). An input clamp diode with a resistor to the IC input terminal can be used. 2.0 Capacitive Load Tolerance The LMV721/722 can directly drive 4700pF in unity-gain without oscillation. The unity-gain follower is the most sensitive configuration to capacitive loading. Direct capacitive loading reduces the phase margin of amplifiers. The combination of the amplifier’s output impedance and the capacitive load induces phase lag. This results in either an underdamped pulse response or oscillation. To drive a heavier capacitive load, circuit in Figure 1 can be used. DS100922-18 FIGURE 1. Indirectly Driving A capacitive Load Using Resistive Isolation In Figure 1, the isolation resistor RISO and the load capacitor CL form a pole to increase stability by adding more phase margin to the overall system. the desired performance depends on the value of RISO. The bigger the RISO resistor value, the more stable VOUT will be. Figure 2 is an output waveform of Figure 1 using 100kΩ for RISO and 2000µF for C L. DS100922-31 FIGURE 2. Pulse Response of the LMV721 Circuit in Figure 1 The circuit in Figure 3 is an improvement to the one in Figure 1 because it provides DC accuracy as well as AC stability. If there were a load resistor in Figure 1, the output would be voltage divided by RISO and the load resistor. Instead, in Figure 3, RF provides the DC accuracy by using feed-forward techniques to connect VIN to RL. Caution is needed in choosing the value of RF due to the input bias current of the LMV721/722. CF and RISO serve to counteract the loss of phase margin by feeding the high frequency component of the output signal back to the amplifier’s inverting input, thereby preserving phase margin in the overall feedback www.national.com 8 Application Notes (Continued) loop. Increased capacitive drive is possible by increasing the value of CF. This in turn will slow down the pulse response. DS100922-21 DS100922-19 FIGURE 3. Indirectly Driving A Capacitive Load with DC Accuracy 3.0 Input Bias Current Cancellation The LMV721/722 family has a bipolar input stage. The typical input bias current of LMV721/722 is 260nA with 5V supply. Thus a 100kΩ input resistor will cause 26mV of error voltage. By balancing the resistor values at both inverting and non-inverting inputs, the error caused by the amplifier’s input bias current will be reduced. The circuit in Figure 4 shows how to cancel the error caused by input bias current. FIGURE 5. Difference Application 4.2 Instrumentation Circuits The input impendance of the previous difference amplifier is set by the resistor R1, R2, R3 and R4. To eliminate the problems of low input impendance, one way is to use a voltage follower ahead of each input as shown in the following two instrumentation amplifiers. 4.2.1 Three-op-amp Instrumentation Amplifier The LMV721/722 can be used to build a three-op-amp instrumentation amplifier as shown in Figure 6 DS100922-20 FIGURE 4. Cancelling the Error Caused by Input Bias Current 4.0 Typical Single-Supply Application Circuits 4.1 Difference amplifier The difference amplifier allows the subtraction of two voltages or, as a special case, the cancellation of a signal common to two inputs. It is useful as a computational amplifier, in making a differential to single-ended conversion or in rejecting a common mode signal. DS100922-30 FIGURE 6. Three-op-amp Instrumentation Amplifier The first stage of this instrumentation amplifier is a differential-input, differential-output amplifier, with two voltage followers. These two voltage followers assure that the input impedance is over 100MΩ. The gain of this instrumentation amplifier is set by the ratio of R2/R1. R3 should equal R1 and R4 equal R2. Matching of R3 to R1 and R4 to R2 affects the CMRR. For good CMRR over temperature, low drift resistors should be used. Making R4 slightly smaller than R2 and adding a trim pot equal to twice the difference between R2 and R4 will allow the CMRR to be adjusted for optimum. 4.2.2 Two-op-amp Instrumentation Amplifier A two-op-amp instrumentation amplifier can also be used to make a high-input impedance DC differential amplifier (Figure 7). As in the two-op-amp circuit, this instrumentation amplifier requires precise resistor matching for good CMRR. R4 should equal to R1 and R3 should equal R2. 9 www.national.com Application Notes (Continued) 4.4 Active Filter 4.4.1 Simple Low-Pass Active Filter The simple low-pass filter is shown in Figure 9. Its low-pass frequency gain (ω → o) is defined by −R3/R1. This allows low-frequency gains other than unity to be obtained. The filter has a −20dB/decade roll-off after its corner frequency fc. R2 should be chosen equal to the parallel combination of R1 and R3 to minimize error due to bais current. The frequency response of the filter is shown in Figure 10. DS100922-22 FIGURE 7. Two-op-amp Instrumentation Amplifier 4.3 Single-Supply Inverting Amplifier There may be cases where the input signal going into the amplifier is negative. Because the amplifier is operating in single supply voltage, a voltage divider using R3 and R4 is implemented to bias the amplifier so the input signal is within the input common-common voltage range of the amplifier. The capacitor C1 is placed between the inverting input and resistor R1 to block the DC signal going into the AC signal source, VIN. The values of R1 and C1 affect the cutoff frequency, fc = 1⁄2π R1C1. As a result, the output signal is centered around mid-supply (if the voltage divider provides V+/2 at the non-inverting input). The output can swing to both rails, maximizing the signal-to-noise ratio in a low voltage system. DS100922-24 FIGURE 9. Simple Low-Pass Active Filter DS100922-25 DS100922-23 FIGURE 10. Frequency Response of Simple Low-pass Active Filter in Figure 9 Note that the single-op-amp active filters are used in to the applications that require low quality factor, Q(≤ 10), low frequency (≤ 5KHz), and low gain (≤ 10), or a small value for the product of gain times Q(≤ 100). The op amp should have an open loop voltage gain at the highest frequency of interest at least 50 times larger than the gain of the filter at this frequency. In addition, the selected op amp should have a slew rate that meets the following requirement: Slew Rate ≥ 0.5 x (ωH VOPP) X 10 −6V/µsec Where ωH is the highest frequency of interest, and VOPP is the output peak-to-peak voltage. FIGURE 8. Single-Supply Inverting Amplifier www.national.com 10 Application Notes (Continued) DS100922-44 FIGURE 11. A Battery Powered Microphone Preamplifier Here is a LMV721 used as a microphone preamplifier. Since the LMV721 is a low noise and low power op amp, it makes it an ideal candidate as a battery powered microphone preamplifier. The LMV721 is connected in an inverting configuration. Resistors, R1 = R2 = 4.7kΩ, sets the reference half way between VCC = 3V and ground. Thus, this configures the op amp for single supply use. The gain of the preamplifier, which is 50 (34dB), is set by resistors R3 = 10kΩ and R4 = 500kΩ. The gain bandwidth product for the LMV721 is 10 MHz. This is sufficient for most audio application since the audio range is typically from 20 Hz to 20kHz. A resistor R5 = 5kΩ is used to bias the electret microphone. Capacitors C1 = C2 = 4.7µF placed at the input and output of the op amp to block out the DC voltage offset. 11 www.national.com Physical Dimensions inches (millimeters) unless otherwise noted SC70-5 Order Number LMV721M7 or LMV721M7X NS Package Number MAA05A www.national.com 12 Physical Dimensions inches (millimeters) unless otherwise noted (Continued) SOT 23-5 Order Number LMV721M5 or LMV721M5X NS Package Number MA05B 13 www.national.com Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 8-Pin Small Outline Order Number LMV722M or LMV722MX NS Package Number M08A www.national.com 14 LMV721/LMV72210MHz, Low Noise, Low Voltage, and Low Power Operational Amplifier Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 8-Pin MSOP Order Number LMV722MM or LMV722MMX NS Package Number MUA08A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation Americas Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: support@nsc.com www.national.com National Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 1 80-530 85 85 English Tel: +49 (0) 1 80-532 78 32 Français Tel: +49 (0) 1 80-532 93 58 Italiano Tel: +49 (0) 1 80-534 16 80 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Asia Pacific Customer Response Group Tel: 65-2544466 Fax: 65-2504466 Email: sea.support@nsc.com National Semiconductor Japan Ltd. Tel: 81-3-5639-7560 Fax: 81-3-5639-7507 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.