LMH6732 High Speed Op Amp with Adjustable Bandwidth General Description Features The LMH6732 is a high speed op amp with a unique combination of high performance, low power consumption, and flexibility of application. The supply current is adjustable, over a continuous range of more than 10 to 1, with a single resistor, RP. This feature allows the device to be used in a wide variety of high performance applications including device turn on/ turn off (Enable/ Disable) for power saving or multiplexing. Typical performance at any supply current is exceptional. The LMH6732’s design has been optimized so that the output is well behaved, eliminating spurious outputs on "Enable". n Exceptional Performance at any Supply Current: VS = ± 5V, TA = 25˚C, AV = +2V/V, VOUT = 2VPP, Typical unless Noted: The LMH6732’s combination of high performance, low power consumption, and large signal performance makes it ideal for a wide variety of remote site equipment applications such as battery powered test instrumentation and communications gear. Other applications include video switching matrices, ATE and phased array radar systems. The LMH6732 is available in the SOIC and SOT23-6 packages. To reduce design times and assist in board layout, the LMH6732 is supported by an evaluation board. n Ultra High Speed (−3dB BW) ICC (mA) n n n n n n -3dB BW (MHz) DG/DP (%/ deg.) PAL Slew Rate (V/µs) THD 1MHz (dBc) Output Current (mA) 1.0 55 0.020/ 0.036 400 -70.0 9 3.4 180 0.022 / 0.017 2100 -78.5 45 9.0 540 0.025 / 0.010 2700 -79.6 115 1.5GHz (ICC = 10mA, 0.25VPP) Single resistor adjustability of supply current Fast enable/ disable capability 20ns (ICC = 9mA) "Popless" output on "Enable" 15mV (ICC = 1mA) < 1µA Ultra low disable current Unity gain stable Improved Replacement for CLC505 & CLC449 Applications n n n n −3dB BW vs. ICC Turn-On/Off Characteristics 20060262 © 2004 National Semiconductor Corporation Battery powered systems Video switching and distribution Remote site instrumentation Mobile communications gear DS200602 20060250 www.national.com LMH6732 High Speed Op Amp with Adjustable Bandwidth March 2004 LMH6732 Absolute Maximum Ratings (Note 1) Human Body Model If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Machine Model IOUT Thermal Resistance (Note 3) ICC 14mA V− to V+ Common Mode Input Voltage Maximum Junction Temperature Storage Temperature Range 200V Operating Ratings (Note 1) ± 6.75V VS 2000V +150˚C Package θJC (˚C/W) θJA (˚C/W) 8-Pin SOIC 65˚C/W 166˚C/W 6-Pin SOT23 120˚C/W 198˚C/W Operating Temperature −65˚C to +150˚C −40˚C to +85˚C ± 4.5V to ± 6V Nominal Supply Voltage Soldering Information Infrared or Convection (20 sec) 235˚C Wave Soldering (10 sec) 260˚C 0.5mA < ICC < 12mA Operating Supply Current ESD Tolerance (Note 4) Electrical Characteristics ICC = 9mA (Note 2) AV = +2, RF = 700Ω, VS = ± 5V, RL = 100Ω, RP = 39kΩ; Unless otherwise specified. Symbol Parameter Conditions Min (Note 6) Typ (Note 6) Max (Note 6) Units Frequency Domain Response SSBW -3dB Bandwidth VOUT = 2VPP 540 MHz LSBW -3dB Bandwidth VOUT = 4.0VPP 315 MHz GF0.1dB 0.1dB Gain Flatness VOUT = 2VPP 180 MHz GFP Frequency Response Peaking DC to 200MHz, VOUT = 2VPP 0.01 dB GFR Frequency Response Rolloff DC to 200MHz, VOUT = 2VPP 0.15 dB LPD Linear Phase Deviation DC to 200MHz, VOUT = 2VPP 0.6 DC to 140MHz, VOUT = 2VPP 0.1 deg DG Differential Gain RL = 150Ω, 4.43MHz 0.025 % DP Differential Phase RL = 150Ω, 4.43MHz 0.010 deg Time Domain Response TRS Rise Time 2V Step 0.8 TRL Fall Time 2V Step 0.9 ns TS Settling Time to 0.04% AV = −1, 2V Step 18 ns OS Overshoot 2V Step 1 % SR Slew Rate 5V Step, 40% to 60% (Note 5) 2700 V/µs Distortion And Noise Response HD2 2nd Harmonic Distortion 2VPP, 20MHz −60 dBc HD3 3rd Harmonic Distortion 2VPP, 20MHz −64 dBc THD Total Harmonic Distortion 2VPP, 1MHz −79.6 V Input Referred Voltage Noise > 1MHz > 1MHz 2.5 nV/ 9.7 pA/ > 1MHz 1.8 pA/ −154 dBm1Hz 60 µV N IN Input Referred Inverting Noise Current INN Input Referred Non-Inverting Noise Current SNF Noise Floor > 1MHz INV Total Integrated Input Noise 1MHz to 200MHz dBc Static, DC Performance VIO ± 3.0 Input Offset Voltage ± 8.0 mV 9.9 DVIO Input Offset Voltage Average Drift www.national.com (Note 8) 16 2 µV/˚C LMH6732 Electrical Characteristics ICC = 9mA (Note 2) (Continued) AV = +2, RF = 700Ω, VS = ± 5V, RL = 100Ω, RP = 39kΩ; Unless otherwise specified. Symbol Parameter Conditions Min (Note 6) Typ (Note 6) Max (Note 6) −2 ± 11 ± 12 Units µA IBN Input Bias Current Non Inverting (Note 7) DIBN Input Bias Current Average Drift Non-Inverting (Note 8) 5 IBI Input Bias Current Inverting (Note 7) −9 DIBI Input Bias Current Average Drift Inverting (Note 8) −14 nA/˚C +PSRR Positive Power Supply Rejection Ratio DC 52 50 62 dB −PSRR Negative Power Supply Rejection Ratio DC 51 48 56 dB CMRR Common Mode Rejection Ratio DC 49 46 52 dB ICC Supply Current RL = ∞, RP = 39kΩ 7.5 6.6 9.0 ICCI Supply Current During Shutdown nA/˚C ± 20 ± 30 10.5 11.7 µA mA <1 µA MΩ Miscellaneous Performance RIN Input Resistance Non-Inverting 4.7 CIN Input Capacitance Non-Inverting 1.8 pF ROUT Output Resistance Closed Loop 32 mΩ VO Output Voltage Range RL = ∞ RL = 100Ω VOL CMIR ± 3.60 ± 3.55 ± 2.90 ± 2.85 Common Mode Input Range Common Mode ± 75 ± 3.75 ± 2.2 ± 115 IO Output Current Closed Loop −40mV ≤ VO ≤ 40mV TON Turn-on Time 0.5VPP Sine Wave, 90% of Full Value 20 TOFF Turn-off Time 0.5VPP Sine Wave, < 5% of Full Value 9 VO glitch Turn-on Glitch FDTH Feed-Through f = 10MHz, AV = +2, Off State V ± 3.10 V mA ns 50 mV −61 dB Electrical Characteristics ICC = 3.4mA (Note 2) AV = +2, RF = 1kΩ, VS = ± 5V, RL = 100Ω, RP = 137kΩ; Unless otherwise specified. Symbol Parameter Conditions Min (Note 6) Typ (Note 6) Max (Note 6) Units Frequency Domain Response SSBW -3dB Bandwidth VOUT = 2VPP 180 MHz LSBW -3dB Bandwidth VOUT = 4.0VPP 100 MHz GF0.1dB 0.1dB Gain Flatness VOUT = 2VPP 50 MHz GFP Frequency Response Peaking DC to 75MHz, VOUT = 2VPP 0.15 dB GFR Frequency Response Rolloff DC to 75MHz, VOUT = 2VPP 0.05 dB LPD Linear Phase Deviation DC to 55MHz, VOUT = 2VPP 0.5 DC to 25MHz, VOUT = 2VPP 0.1 deg DG Differential Gain RL = 150Ω, 4.43MHz 0.022 % DP Differential Phase RL = 150Ω, 4.43MHz 0.017 deg Time Domain Response 3 www.national.com LMH6732 Electrical Characteristics ICC = 3.4mA (Note 2) (Continued) AV = +2, RF = 1kΩ, VS = ± 5V, RL = 100Ω, RP = 137kΩ; Unless otherwise specified. Symbol Parameter Conditions Min (Note 6) Typ (Note 6) Max (Note 6) Units TRS Rise Time 2V Step 1.7 TRL Fall Time 2V Step 2.1 TS Settling Time to 0.04% AV = −1, 2V Step 18 OS Overshoot 2V Step 2 % SR Slew Rate 5V Step, 40% to 60% (Note 5) 2100 V/µs ns ns Distortion And Noise Response HD2 2nd Harmonic Distortion 2VPP, 10MHz −51 dBc HD3 3rd Harmonic Distortion 2VPP, 10MHz −65 dBc THD Total Harmonic Distortion 2VPP, 1MHz −78.5 dBc Input Referred Voltage Noise > 1MHz > 1MHz 4.1 nV/ 8.8 pA/ pA/ V N IN Input Referred Inverting Noise Current INN Input Referred Non-Inverting Noise Current > 1MHz 1.1 SNF Noise Floor > 1MHz −151 dBm1Hz INV Total Integrated Input Noise 1MHz to 100MHz 60 µV Static, DC Performance ± 2.5 ± 7.0 ± 8.5 VIO Input Offset Voltage DVIO Input Offset Voltage Average Drift (Note 8) IBN Input Bias Current Non Inverting (Note 7) DIBN Input Bias Current Average Drift Non-Inverting (Note 8) 8 IBI Input Bias Current Inverting (Note 7) −1 DIBI Input Bias Current Average Drift Inverting (Note 8) −3 nA/˚C +PSRR Positive Power Supply Rejection Ratio DC 52 50 64 dB −PSRR Negative Power Supply Rejection Ratio DC 51 50 57 dB CMRR Common Mode Rejection Ratio DC 49 48 55 dB ICC Supply Current RL = ∞, RP = 137kΩ 2.8 2.6 3.4 ICCI Supply Current During Shutdown 10 −0.4 mV µV/˚C ±4 ±6 µA nA/˚C ± 12 ± 16 3.9 4.1 µA mA <1 µA MΩ Miscellaneous Performance RIN Input Resistance Non-Inverting 15 CIN Input Capacitance Non-Inverting 1.7 pF ROUT Output Resistance Closed Loop 50 mΩ VO Output Voltage Range RL = ∞ ± 3.60 ± 3.55 ± 2.90 ± 2.85 RL = 100Ω VOL CMIR Common Mode Input Range Common Mode IO Output Current Closed Loop −20mV ≤ VO ≤ 20mV www.national.com 4 ± 30 ± 3.78 ± 3.10 ± 2.2 ± 45 V V mA LMH6732 Electrical Characteristics ICC = 3.4mA (Note 2) (Continued) AV = +2, RF = 1kΩ, VS = ± 5V, RL = 100Ω, RP = 137kΩ; Unless otherwise specified. Symbol Parameter Conditions Min (Note 6) Typ (Note 6) TON Turn-on Time 0.5VPP Sine Wave, 90% of Full Value 42 TOFF Turn-off Time 0.5VPP Sine Wave, < 5% of Full Value 10 VO glitch Turn-on Glitch FDTH Feed-Through f = 10MHz, AV = +2, Off State Max (Note 6) Units ns 25 mV −61 dB Electrical Characteristics ICC = 1.0mA (Note 2) AV = +2, RF = 1kΩ, VS = ± 5V, RL = 500Ω, RP = 412kΩ; Unless otherwise specified. Symbol Parameter Conditions Min (Note 6) Typ (Note 6) Max (Note 6) Units Frequency Domain Response SSBW -3dB Bandwidth VOUT = 2VPP 55 MHz LSBW -3dB Bandwidth VOUT = 4.0VPP 30 MHz GF0.1dB 0.1dB Gain Flatness VOUT = 2VPP 20 MHz GFP Frequency Response Peaking DC to 25MHz, VOUT = 2VPP 0.11 dB GFR Frequency Response Rolloff DC to 25MHz, VOUT = 2VPP 0.05 dB LPD Linear Phase Deviation DC to 20MHz, VOUT = 2VPP 1 DC to 14MHz, VOUT = 2VPP 0.3 deg DG Differential Gain RL = 500Ω, 4.43MHz 0.020 % DP Differential Phase RL = 500Ω, 4.43MHz 0.036 deg Time Domain Response TRS Rise Time 2V Step 3.7 TRL Fall Time 2V Step 5.1 ns TS Settling Time to 0.04% AV = −1, 2V Step 18 OS Overshoot 2V Step 2 % SR Slew Rate 5V Step, 40% to 60% (Note 5) 400 V/µs ns Distortion And Noise Response HD2 2nd Harmonic Distortion 2VPP, 5MHz −43 dBc HD3 3rd Harmonic Distortion 2VPP, 5MHz −65 dBc THD Total Harmonic Distortion 2VPP, 1MHz −70.0 V Input Referred Voltage Noise > 1MHz > 1MHz 8.4 nV/ 9.0 pA/ > 1MHz 0.8 pA/ −147 dBm1Hz 29 µV N IN Input Referred Inverting Noise Current INN Input Referred Non-Inverting Noise Current SNF Noise Floor > 1MHz INV Total Integrated Input Noise 1MHz to 100MHz dBc Static, DC Performance ± 1.6 VIO Input Offset Voltage DVIO Input Offset Voltage Average Drift (Note 8) IBN Input Bias Current Non Inverting (Note 7) DIBN Input Bias Current Average Drift Non-Inverting (Note 8) IBI Input Bias Current Inverting (Note 7) ± 6.0 ± 7.3 4 5 0.04 µV/˚C ± 2.0 ± 2.5 −1 −0.1 mV µA nA/˚C ±6 ±8 µA www.national.com LMH6732 Electrical Characteristics ICC = 1.0mA (Note 2) (Continued) AV = +2, RF = 1kΩ, VS = ± 5V, RL = 500Ω, RP = 412kΩ; Unless otherwise specified. Symbol Parameter Conditions DIBI Input Bias Current Average Drift Inverting (Note 8) +PSRR Positive Power Supply Rejection Ratio DC −PSRR Negative Power Supply Rejection Ratio CMRR Min (Note 6) Typ (Note 6) Max (Note 6) Units −3 nA/˚C 52 51 64 dB DC 51 49 59 dB Common Mode Rejection Ratio DC 49 47 55 dB ICC Supply Current RL = ∞, RP = 412kΩ 0.70 0.66 1.0 ICCI Supply Current During Shutdown 1.3 1.4 mA <1 µA MΩ Miscellaneous Performance RIN Input Resistance Non-Inverting 46 CIN Input Capacitance Non-Inverting 1.7 pF ROUT Output Resistance Closed Loop 100 mΩ VO Output Voltage Range RL = ∞ ± 3.60 ± 3.55 ± 2.90 ± 2.85 RL = 500Ω VOL ± 3.78 ± 3.10 ± 2.2 ±9 V V CMIR Common Mode Input Range Common Mode IO Output Current Closed Loop −15mV ≤ VO ≤ 15mV TON Turn-on Time 0.5VPP Sine Wave, 90% of Full Value 95 TOFF Turn-off Time 0.5VPP Sine Wave, < 5% of Full Value 40 15 mV f = 10MHz, AV = +2, Off State −61 dB VO glitch Turn-on Glitch FDTH Feed-Through ±6 mA ns 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, see the Electrical Characteristics tables. Note 2: 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. Min/Max ratings are based on production testing unless otherwise specified. Note 3: The maximum output current (IO) is determined by device power dissipation limitations. Note 4: Human body model: 1.5kΩ in series with 100pF. Machine model: 0Ω in series with 200pF. Note 5: Slew Rate is the average of the rising and falling edges. Note 6: Typical numbers are the most likely parametric norm. Bold numbers refer to over temperature limits. Note 7: Negative input current implies current flowing out of the device. Note 8: Drift determined by dividing the change in parameter distribution average at temperature extremes by the total temperature change. www.national.com 6 LMH6732 Connection Diagrams 8-Pin SOIC 6-Pin SOT23 20060201 20060202 Top View Top View Ordering Information Package Part Number Package Marking Transport Media NSC Drawing 8-pin SOIC LMH6732MA LMH6732MA 95 Units/Rail M08A LMH6732MAX 6-Pin SOT23 LMH6732MF 2.5k Units Tape and Reel A97A 1k Units Tape and Reel LMH6732MFX MF06A 3k Units Tape and Reel 7 www.national.com LMH6732 Typical Performance Characteristics Frequency Response ICC = 3.4mA Frequency Response ICC = 9mA 20060209 20060211 Frequency Response ICC = 1mA 20060215 Frequency Response ICC = 3.4mA Frequency Response ICC = 9mA 20060217 20060213 Frequency Response ICC = 3.4mA Frequency Response ICC = 9mA 20060210 www.national.com Frequency Response ICC = 1mA Frequency Response ICC = 1mA 20060214 8 20060219 20060218 Frequency Response ICC = 9mA (Continued) Frequency Response ICC = 3.4mA Frequency Response ICC = 1mA 20060216 20060212 Noise ICC = 3.4mA Noise ICC = 9mA 20060229 20060220 Noise ICC = 1mA 20060230 CMRR and PSRR ICC = 3.4mA CMRR and PSRR ICC = 9mA LMH6732 Typical Performance Characteristics 20060205 CMRR and PSRR ICC = 1mA 20060204 9 20060231 20060203 www.national.com LMH6732 Typical Performance Characteristics 2nd Distortion vs. Output Amplitude ICC = 9mA (Continued) 2nd Distortion vs. Output Amplitude ICC = 3.4mA 20060223 3rd Distortion vs. Output Amplitude ICC = 9mA 20060225 3rd Distortion vs. Output Amplitude ICC = 3.4mA 20060224 Frequency Response for Various CL ICC = 9mA 20060226 Frequency Response for Various CL ICC = 3.4mA 20060255 www.national.com 20060256 10 2nd Distortion vs. Output Amplitude ICC = 1mA 20060227 3rd Distortion vs. Output Amplitude ICC = 1mA 20060222 Frequency Response for Various CL ICC = 1mA 20060257 Small Signal Step Response ICC = 9mA (Continued) Small Signal Step Response ICC = 3.4mA 20060221 20060243 Large Signal Step Response ICC = 3.4mA Large Signal Step Response ICC = 9mA 20060245 20060241 Large Signal Step Response ICC = 1mA 20060244 Output Glitch ICC = 3.4mA Output Glitch ICC = 9mA Small Signal Step Response ICC = 1mA 20060247 Output Glitch ICC = 1mA 20060248 11 20060242 20060249 www.national.com LMH6732 Typical Performance Characteristics LMH6732 Typical Performance Characteristics Turn-On/Off Characteristics ICC = 9mA (Continued) Turn-On/Off Characteristics ICC = 3.4mA 20060250 ICC vs. RP 20060251 IP vs. ICC 20060235 Slew Rate vs. ICC BW vs. ICC 20060236 BW vs. ICC for Various Temperature 20060238 12 20060252 Max Output Current vs. ICC 20060240 20060237 www.national.com Turn-On/Off Characteristics ICC = 1mA 20060239 −3dB BW vs. ICC (Continued) VOS, IBI & IBN VS. ICC Output Impedance vs. Frequency 20060262 Transimpedance Recommended RS vs. CL 20060232 Settling Time 20060228 20060254 DG/DP for Various RL ICC = 9mA DG/DP ICC = 9mA 20060233 20060234 DG/DP for Various RL ICC = 3.4mA 20060207 20060206 13 20060208 www.national.com LMH6732 Typical Performance Characteristics LMH6732 Application Information: TABLE 1. Device Parameters Related to Supply Current Effect as ICC Increases Increases Rise Time Decreases Enable/ Disable Speed Increases Output Drive Increases Input Bias Current Increases Input Impedance Decreases (see Source impedance Discussion) Both the Electrical Characteristics pages and the Typical Performance Characteristics section illustrate these effects to help make the supply current vs. performance trade-off. The supply current is adjustable over a continuous range of more than 10 to 1 with a single resistor, RP, allowing for easy trade-off between power consumption and speed. Performance is specified and tested at ICC = 1mA, 3.4mA, and 9mA. (Note: Some test conditions and especially the load resistances are different for the three supply current settlings.) The performance plots show typical performance for all three supply currents levels. When making the supply current vs. performance trade-off, it is first a good idea to see if one of the standard operating points (ICC = 1mA, 3.4mA, or 9mA) fits the application. If it does, performance guaranteed on the specification pages will apply directly to your application. In addition, the value of RP may be obtained directly from the Electrical Characteristics pages. 20060258 FIGURE 1. Recommended Non-Inverting Gain Circuit BEYOND 1GHz BANDWIDTH As stated above, the LMH6732 speed can be increased by increasing the supply current. The −3dB Bandwidth can even reach the unprecedented value of 1.5GHz (AV = +2, VOUT = 0.25VPP). Of course, this comes at the expense of power consumption (i.e. supply current). The relationship between −3dB BW and supply current is shown in the Typical Performance Characteristics section. The supply current would nominally have to be set to around 10mA to achieve this speed. The absolute maximum supply current setting for the LMH6732 is 14mA. Beyond this value, the operation may become unpredictable. The following discussion will assist in selecting ICC for applications that cannot operate at one of the specified supply current settlings. Use the typical performance plots for critical specifications to select the best ICC. For parameters containing Min/Max ratings in the data sheet tables, interpolate between the values of ICC in the plots & specification tables to estimate the max/min values in the application. The simplified schematic for the supply current setting path (IP) is shown below in Figure 3. 20060259 FIGURE 2. Recommended Inverting Gain Circuit DESCRIPTION The LMH6732 is an adjustable supply current, currentfeedback operational amplifier. Supply current and consequently dynamic performance can be easily adjusted by selecting the value of a single external resistor (RP). Note: Note: The following discussion uses the SOIC package pin numbers. For the corresponding SOT23-6 package pin numbers, please refer to the Connection Diagram section. SELECTING AN OPERATING POINT The operating point is determined by the supply current which in turn is determined by current (IP) flowing out of pin 8. As the supply current is increased, the following effects will be observed: www.national.com Specification Bandwidth 14 DYNAMIC SHUTDOWN CAPABILITY (Continued) The LMH6732 may be powered on and off very quickly by controlling the voltage applied to RP. If RP is connected between pin 8 and the output of a CMOS gate powered from ± 5V supplies, the gate can be used to turn the amplifier on and off. This is shown in Figure 4 below: 20060260 FIGURE 4. Dynamic Control of Power Consumption Using CMOS Logic 20060246 FIGURE 3. Supply Current Control’s Simplified Schematic When the gate output is switched from high to low, the LMH6732 will turn on. In the off state, the supply current typically reduces to 1µA or less. The LMH6732’s "off state" supply current is reduced significantly compared to the CLC505. This extremely low supply current in the "off state" is quite advantageous since it allows for significant power saving and minimizes feed-through. To improve switching time, a speed up capacitor from the gate output to pin 8 is recommended. The value of this capacitor will depend on the RP value used and is best established experimentally. Turn-on and turn-off times of < 20ns (ICC = 9mA) are achievable with ordinary CMOS gates. The terminal marked "RP" is tied to a potential through a resistor RP. The current flowing through RP (IP) sets the LMH6732’s supply current. Throughout the data sheet, the voltages applied to RP and V− are both considered to be −5V. However, the two potentials do not necessarily have to be the same. This is beneficial in applications where nonstandard supply voltages are used or when there is a need to power down the op amp via digital logic control. The relationship between ICC and IP is given by: lP = ICC/57 (approximate ratio at ICC = 3.4mA; consult “ICC vs. IP” plot for relationship at any ICC). Knowing IP leads to a direct calculation of RP. RP + 5kΩ = [(V+ -1.6)-V−]/ IP EXAMPLE An open collector logic device is used to dynamically control the power dissipation of the circuit. Here, the desired connection for RP is from pin 8 to the open collector logic device. RP+ 5kΩ= =8.4 /IP (for V+ = 5V and V− = −5V). First, an operating point needs to be determined from the plots & specifications as discussed above. From this, IP is obtained. Knowing IP and the potential RP is tied to, RP can be calculated. EXAMPLE An application requires that VS = ± 3V and performance in the 1mA operating point range. The required IP can therefore be determined as follows: IP=21µA RP is connected from pin 8 to V−. Calculate RP under these conditions: RP+ 5kΩ = [(V+ -1.6)-V−] / IP RP+ 5kΩ = [(3V-1.6V) - (-3V)] / 21µA RP = 205kΩ The LMH6732 will have performance similar to RP = 412kΩ shown on the datasheet, but with 40% less power dissipation due to the reduced supply voltages. The op amp will also have a more restricted common-mode range and output swing. 20060261 FIGURE 5. Controlling Power On State with TTL Logic (Open Collector Output) When the logic gate goes low, the LMH6732 is turned on. The LMH6732 V+ connection would be to +5V supply. Performance desired is that given for ICC = 3.4mA under standard conditions. From the ICC vs. IP plot, IP = 61µA. Then calculating RP: RP + 5kΩ = [(5V-1.6V)- 0] / 61µA RP = 51kΩ 15 www.national.com LMH6732 Application Information: LMH6732 Application Information: (Continued) "POPLESS OUTPUT" & OFF CONDITION OUTPUT STATE The LMH6732 has been especially designed to have minimum glitches during turn-on and turn-off. This is advantageous in situations where the LMH6732 output is fed to another stage which could experience false auto-ranging, or even worse reset operation, due to these transient glitches. Example of this application would be an AGC circuit or an ADC with multiple ranges set to accommodate the largest input amplitude. For the LMH6732, these sorts of transients are typically less than 50mV in amplitude (see Electrical Characteristics Tables for Typical values). Applications designed to utilize the CLC505’s low output glitch would benefit from using the LMH6732 instead since the LMH6732’s output glitch is improved to be even lower than the CLC505’s. In the "Off State", the output stage is turned off and is in effect put into a high-Z state. In this sate, output can be forced by other active devices. No significant current will flow through the device output pin in this mode of operation. 20060264 FIGURE 7. MUX “VOUT” and “Control” Waveform DIFFERENTIAL GAIN AND PHASE MUX APPLICATION Since The LMH6732’s output is essentially open in the “off” state, it is a good candidate for a fast 2:1 MUX. Figure 6 shows one such application along with the output waveform in Figure 7 displaying the switching between a continuous triangle wave and a single cycle sine wave (signals trigger locked to each other for stable scope photo). Switching speed of the MUX will be less than 50 ns and is governed by the “Ton" and “Toff” times for U1 and U2 at the supply current set by RP1 and RP2. Note that the “Control” input is a 5V CMOS logic level. Differential gain and phase are measurements useful primarily in composite video channels. They are measured by monitoring the gain and phase changes of a high frequency carrier (3.58MHz for NTSC and 4.43MHz for PAL systems) as the output of the amplifier is swept over a range of DC voltages. Specifications for the LMH6732 include differential gain and phase. Test signals used are based on a 1VPP video level. Test conditions used are the following: DC sweep range: 0 to 100 IRE units (black to white) Carrier: 4.43MHz at 40 IRE units peak to peak AV = +2, RL = 75Ω + 75Ω SOURCE IMPEDANCE For best results, source impedance in the non-inverting circuit configuration (see Figure 1) should be kept below 5kΩ. Above 5kΩ it is possible for oscillation to occur, depending on other circuit board parasitics. For high signal source impedances, a resistor with a value of less than 5kΩ may be used to terminate the non-inverting input to ground. FEEDBACK RESISTOR In current-feedback op amps, the value of the feedback resistor plays a major role in determining amplifier dynamics. It is important to select the correct value. The LMH6732 provides optimum performance with feedback resistors as shown in Table 2 below. Selection of an incorrect value can lead to severe rolloff in frequency response, (if the resistor value is too large) or , peaking or oscillation (if the value is too low). 20060263 FIGURE 6. 50 ns 2:1 MUX Schematic www.national.com 16 ground will cause frequency response peaking and possible circuit oscillations (see Application Note OA-15 for more information). National Semiconductor suggests the following evaluation boards as a guide for high frequency layout and as an aid in device testing and characterization: (Continued) TABLE 2. Feedback Resistor Selection for Various Gain Settings and ICC’s Gain (V/V) ICC (mA) Unit 9 3.4 1 AV = +1 700 1k 1k Ω AV = +2 700 1k 1k Ω AV = −1 500 750 Device Package Evaluation Board Part Number LMH6732MF SOT23-6 CLC730216 SOIC CLC730227 1k Ω LMH6732MA These evaluation boards are shipped when a device sample request is placed with National Semiconductor. The supply current adjustment resistor, RP, in both evaluation boards should be tied to the appropriate potential to get the desired supply current. To do so, leave R2 (CLC730216) [ R5 (CLC730227) ] uninstalled. Jumper "Dis" connector to V−. Install R1 (CLC730216) [ R4 (CLC730227) ] to set the supply current. AV = −2 400 450 1k Ω AV = +6 500 500 1k Ω AV = −6 200 200 1k Ω AV = +21 1k 1k 1k Ω AV = −20 500 500 1k Ω For ICC > 9mA at any closed loop gain setting, a good starting point for RF would be the 9mA value stated in Table 2 above. This value could then be readjusted, if necessary, to achieve the desired response. PRINTED CIRCUIT LAYOUT & EVALUATION BOARDS Generally, a good high frequency layout will keep power supply and ground traces away from the inverting input and output pins. Parasitic capacitances on these nodes to 17 www.national.com LMH6732 Application Information: LMH6732 Physical Dimensions inches (millimeters) unless otherwise noted 8-Pin SOIC NS Package Number M08A 6-Pin SOT23 NS Package Number MF06A www.national.com 18 LMH6732 High Speed Op Amp with Adjustable Bandwidth Notes 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. 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. BANNED SUBSTANCE COMPLIANCE National Semiconductor certifies that the products and packing materials meet the provisions of the Customer Products Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain no ‘‘Banned Substances’’ as defined in CSP-9-111S2. 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