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National Semiconductor LMC6035/LMC6036 Low Power 2.7V Single Supply CMOS Operational Amplifiers handbook

1. Amp to Amp Isolation vs Amp to Amp Isolation vs PSRR vs Frequency Frequency Frequency 100 170 0 170 0 90 Vs 15V 80 150 0 150 0 3 60 E 5k LI 50 130 0 130 0 F RSV Fa ji E 8 9 2 5 30 E GO Pes sss shield 20 1 1 5k 90 0 9001 500 gt o 10Vp_ MNT E 1 10 100 1k 10k 100k 70 0 Tutu 70 0 Tutu FREQUENCY Hz 1 0 100 k Ok 100k 1 10 100 k Ok 100k 50128309 Frequency Hz Frequency Hz DS012830 61 DS012830 62 PSRR vs Frequency CMRR vs Frequency CMRR vs Input Voltage 100 100 90 Vs 15 Vs 2 7V 90 R 5 Vg 15 i 80 R 5k 80 Vem 1 35V f 10kHz 70 70 60 80 8 60 x 50 s0 40 amp 70 30 40 20 60 30 10 0 IU 50 20 1 10 100 1k 10k 100 10 100 1k 10k 100 1 35 0 75 0 15 045 1 05 14 05 045 045 0 75 1 35 FREQUENCY Hz FREQUENCY Hz DS012830 33 DS012830 34 INPUT VOLTAGE V DS012830 35 CMRR vs Input Voltage Input Voltage vs Input Voltage vs 100 Output Voltage Output Voltage YEIN 250 200 R
2. 10 27 gt 1 lt e 5 0 1 0 01 0 001 0 01 0 1 1 10 Output Voltage Referenced to Vs V DS012830 55 Output Voltage Swing vs Supply Voltage Input Current vs Temperature 50 Vs 1 35V 40 30 20 Input Current fA 35 45 55 65 75 85 Temperature C Sinking Current vs Output Voltage DS012830 53 Sourcing Current vs Output Voltage Typical Performance Characteristics unless otherwise specified Vs 2 7V single supply TA 25 C Sinking Current vs Output Voltage gt 18 E v 16 gt Positive Swing a o 2 12 a s 10 n 8 2 jo 6 4 i 2 Negative Swing 5 2 8 0 6 9 12 15 Supply Voltage V DS012830 58 1
3. 1000 1000 10000 Ay Ay 1 A 10 3 Vs 1 35V Vs 1 35V Vs 1 35 R 2kQ 1MQ R 6000 4 UNSTABLE 2 77 1000 5 5 UNSTABLE 5 S u 100 u 100 gt gt gt 5 F a 25 OVERSHOOT x x lt 100 N 253 OVERSHOOT 25 OVERSHOOT 10 10 10 1 2 0 8 0 4 0 04 08 12 12 08 04 0 04 08 12 1 2 0 8 04 0 0 04 08 12 Your V Your V Van V DS012830 39 DS012830 40 our DS012830 41 Stability vs Stability vs Capacitive Load Capacitive Load 1000 r 1000 a a Y r gt 25 OVERSHOOT E e Q 5 3 25 OVERSHOOT 9 S w 100 100 gt gt o lt lt a Ay 10 5 Ay 10 Vs 1 35V Vs 1 35V R 2 0 R 10 10 1 2 0 8 0 4 0 04 08 12 1 2 0 8 04 0 04 08 12 Your V Your V 05012830 42 05012830 43 www national com 10 1 0 Application Notes 1 1 Background The LMC6035 6 is exceptionally well suited for low voltage applications A desirable feature that the LMC6035 6 brings to low voltage applications is its output drive capability a hallmark for National s CMOS amplifiers The circuit of Fig ure 1 illustrates the drive capability of the LMC6035 6 at 3V of supply It is a differential output driver for a one to one au dio transformer like those used for isolating ground from the telephone lines The transformer T1 loads the
4. National Semiconductor LMC6035 LMC6036 Low Power 2 7V Single Supply CMOS Operational Amplifiers General Description The LMC6035 6 is an economical low voltage op amp ca pable of rail to rail output swing into loads of 600Q LMC6035 is available in a chip sized package 8 Bump mi cro SMD using National s micro SMD package technology Both allow for single supply operation and are guaranteed for 2 7V 3V 5V and 15V supply voltage The 2 7 supply volt age corresponds to the End of Life voltage 0 9V cell for three NiCd or NiMH batteries in series making the LMC6035 6 well suited for portable and rechargeable sys tems It also features a well behaved decrease in its specifi cations at supply voltages below its guaranteed 2 7V opera tion This provides a comfort zone for adequate operation at voltages significantly below 2 7V Its ultra low input cur rents lj makes it well suited for low power active filter ap plication because it allows the use of higher resistor values and lower capacitor values In addition the drive capability of the LMC6035 6 gives these op amps a broad range of appli cations for low voltage systems Connection Diagrams 8 Pin SO MSOP OUTPUT A INVERTING 2 INPUT A NON INVERTING _3 INPUT A OUTPUT B 6 _ INVERTING INPUT B 5 NON INVERTING INPUT B 05012830 1 View 14 50 155 05012830 2 View January 2000 F
5. R2 R2 normaiizeo X Z 10 84k 8 4 Standard value chosen for R1 and R2 is 8 45 kQ 1 2 2 High Pass Active Filter The previous low pass filter circuit of Figure 5 converts to a high pass active filter per Figure 6 R1 j ann 2 normalized values DS012830 49 FIGURE 6 2 Pole 300 Hz Sallen and Key High Pass Filter 1V offset 1 2 2 1 High Pass Frequency Scaling Procedure Choose a standard capacitor value and scale the imped ances in the circuit according to the desired cutoff frequency 300 Hz as follows C C1 C2 2 1 x 2x x desired cutoff freq 1 Farad 6 8 nF x 2x x 300 Hz 78 05k R1 Z x R1 normalized 78 05k x 1 0 707 110 4 Standard value chosen for R1 is 110 R2 Z x R2inormatizea 78 05k x 1 1 414 55 2 Standard value chosen for R1 is 54 9 1 2 3 Dual Amplifier Bandpass Filter The dual amplifier bandpass DABP filter features the ability to independently adjust f Q In most other bandpass to pologies the f and Q adjustments interact with each other The DABP filter also offers both low sensitivity to component values and high Qs The following application of Figure 7 provides a 1 kHz center frequency and a Q of 100 www national com 1 0 Application Notes continued DS012830 50 FIGURE 7 2 Pole 1 kHz Active Bandpass Filter 1 2 3 1 DABP Component Selection Procedure Component
6. 100 1M 10M FREQUENCY Hz DS012830 18 Gain and Phase vs Capacitive Load 80 T 180 BAIN Vg 2 7V R 6000 60 Vi 135 PHASE 40 90 T s a lt amp so 0 45 amp 0 30 pF 0 60 pF 20 45 1k Ok 100k 10 FREQUENCY Hz Non Inverting Large Signal Response DS012830 19 Ty 259 lt e es gt o 2 SL zo L e Es z TIME 1 us div 05012830 21 Slew Rate vs Supply Voltage Vpp Falling Edge HA Rising Edge 2 2 Vin Ay 1 2 0 18 Mer lt gt 16 14 1 2 2 4 6 8 10 Non Inverting vs V 12 14 16 05012830 37 Large Signal Response OUTPUT SIGNAL 40 C 500 mV div INPUT SIGNAL TIME 1 ps div DS012830 22 Non Inverting Large Signal Response lt ree ee er Pree L e 5 gt R 2 0 ott 85 C gt ane z2 5 L e 2 a TIME 1 us div DS012830 20 Non Inverting Small Signal Respo
7. 2 to 7 5V 13 5 min 0 12 0 4 V 0 5 max lo Output Current Vo 0V Sourcing 8 4 mA 3 min Vo 2 7V Sinking 5 3 mA ls Supply Current LMC6035 for Both Amplifiers 0 65 1 6 mA V o 1 35V 1 9 max LMC6036 for All Four Amplifiers 1 3 2 7 mA V o 1 35V 3 0 max www national com 4 AC Electrical Characteristics Unless otherwise specified all limits guaranteed for T 25 C V 2 7V V OV Voy 1 0V V o 1 35V gt 1 MQ Boldface limits apply at the temperature extremes Symbol Parameter Conditions Typ Units Note 5 SR Slew Rate Note 9 15 V us GBW Gain Bandwidth Product V 15V 1 4 MHz O m Phase Margin 48 i Gn Gain Margi d Amp to Amp Isolation Note 10 130 dB e Input Referred Voltage Noise nV 4Hz in Input Referred Current Noise f 1 kHz 0 2 fA V Hz THD Total Harmonic Distortion f 10 kHz Ay 10 2kQ Vo 8 Vpp V 10V Note 1 Absolute Maximum Ratings indicate limits beyond which damage to the device may occur Operating Ratings indicate conditions for which the device is in tended 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 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 j
8. 0 20 10 BENCHMARK 7 0 2 LMC6035 THD NOISE has RM Saa THD Noise a Floor of Measuring Instrument 0 0001 LL 10m 20m 50m 100m p a T TTHHIE 200m 500m 1 AMPLITUDE Vpp DS012830 47 FIGURE 4 THD Noise Performance of LMC6035 and Benchmark per Circuit of Figure 1 Figure 4 shows the superior distortion performance of LMC6035 6 over that of the benchmark op amp The heavy loading of the circuit causes the Ayo of the benchmark part to drop significantly which causes increased distortion 1 2 APPLICATION CIRCUITS 1 2 1 Low Pass Active Filter Acommon application for low voltage systems would be ac tive filters in cordless and cellular phones for example The ultra low input currents of the LMC6035 6 makes it well suited for low power active filter applications because it al lows the use of higher resistor values and lower capacitor values This reduces power consumption and space Figure 5 shows a low pass active filter with a Butterworth maximally flat frequency response Its topology is a Sallen and Key filter with unity gain Note the normalized compo nent values in parenthesis which are obtainable from stan dard filter design handbooks
9. 0 004 0 010 0 102 0 254 EK lt 0 014 0 020 0 356 0 508 REV H 17 www national com 9 099IN 1 5 090W1 LMC6035 LMC6036 Physical Dimensions inches millimeters unless otherwise noted Continued 7 12 4 16 i 0 42 TYP 21 0 65 TYP LAND PATTERN RECOMMENDATION 4 4 0 1 SEE DETAIL a 4 k p 0 09 0 20 TYP PNE 1 7 0 2 c 8 IDENT ALL LEAD TIPS GAGE PLANE 0 9 0 25 ALL LEAD TIPS 1 1 7 0 10 0 05 TYP 0 19 0 30 jo os 0 6 0 1 e c DETAIL A TYPICAL SCALE 40X DIMENSIONS ARE IN MILLIMETERS MTC14 REV C 14 Pin TSSOP NS Package Number MTC14 www national com 18 Physical Dimensions inches millimeters unless otherwise noted Continued SYMM LAND PATTERN RECOMMENDATION B X2 X3 TOP SIDE COATING NOTE 1 mog lt C 0 04 BUMP NOTE 2 0 5 BUMP 1 CORNER 0 14 IN i NOTE 4 SILICON 0 11 0 5 P 8X E 0 005 DIMENSIONS ARE IN MILLIMETERS REV NOTE UNLESS OTHERWISE SPECIFIED 1 EPOXY COATING 2 63Sn 37Pb EUTECTIC BUMP 3 REC
10. 00 Vo 757 gt 10 lt E Li eo e 5 D 1 0 1 0 01 0 1 1 0 00 Output Voltage Referenced to Vs V DS012830 54 0 1000 10 15V 77 100 1 lt 10 lt Ed P d z z a 1 a 0 1 0 1 0 01 0 01 0 001 0 01 0 1 1 10 00 0 001 0 01 0 1 Output Voltage Referenced to GND V Output Voltage Referenced to GND V DS012830 56 DS012830 57 Input Noise vs Input Noise vs Frequency Frequency 110 0 Sooo 130 0 Vs 15V 90 0 gt 292 N N 90 0 gt 700 gt S 8 g 9 500 5 50 0 5 5 30 0 30 0 10 0 10 0 10 100 k Ok 10 00 k Ok Frequency Hz Frequency Hz DS012830 59 DS012830 60 www national com Typical Performance Characteristics unless otherwise specified Vs 2 7V single supply Ta 25 C Continued
11. 3 represent mea surements taken directly at the output relative to GND of U1A in Figure 1 Figure 2 illustrates the output swing capa bility of the LMC6035 while Figure 3 provides a benchmark comparison The benchmark op amp is another low voltage 3V op amp manufactured by one of our reputable competitors DS012830 45 FIGURE 2 Output Swing Performance of the LMC6035 per the Circuit of Figure 1 DS012830 46 FIGURE 3 Output Swing Performance of Benchmark Op Amp per the Circuit of Figure 1 Notice the superior drive capability of LMC6035 when com pared with the benchmark measurement even though the benchmark op amp uses twice the supply current Not only does the LMC6035 6 provide excellent output swing capability at low supply voltages it also maintains high open loop gain A yo with heavy loads To illustrate this the LMC6035 and the benchmark op amp were compared for their distortion performance in the circuit of Figure 1 The graph of Figure 4 shows this comparison The y axis repre sents percent Total Harmonic Distortion THD plus noise across the loaded secondary of T1 The x axis represents the input amplitude of a 1 kHz sine wave Note that T1 loses about 20 of the voltage to the voltage divider of 6000 and T1 s winding resistances a performance deficiency of the transformer www national com 9 099IN 1 5 090W1 LMC6035 LMC6036 1 0 Application Notes continued 100 5
12. 5k 90 t 10482 7200 150 _ 7150 AM 80 A 100 bud i d 50 2 70 0 T S so gt 2 50 60 g 100 z ies Z 100 50 200 150 0 0 3 0 6 0 9 0 12 0 15 0 250 200 15 45 75 105 135 ee eer ee ee Aes er ea ae ae OUTPUT VOLTAGE V OUTPUT VOLTAGE V DS012830 14 DS012830 15 7 www national com 9 090N 1 S 090W 1 LMC6035 LMC6036 Typical Performance Characteristics unless otherwise specified Vs 2 7V single supply T4 25 Continued Frequency Response vs Temperature 80 60 ES o GAIN dB 20 Ok 100k 1M FREQUENCY Hz 180 GAIN Vg 2 7V R 500kQ 135 PHASE 40 C 25 90 S 85 C nn lt 45 F 40 C 4 25 C 4 0 85 C Liu CA 45 Frequency Response vs Temperature 80 60 o GAIN dB 20 GAIN PHASE 9 10k 859 00k FREQUENCY Hz DS012830 16 DS012830 17 Gain and Phase vs Capacitive Load 80 GAIN dB wea GAIN s R 500kQ TTTIT 135 PHASE i lt 1 45 60 pF 0 30 pF 0 pF 45 1k Ok
13. C14 Tape and Reel 8 Bump micro SMD LMC6035IBP 250 Units Tape and Reel BPA08FFB LMC6035IBPX 3k Units Tape and Reel www national com 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 3000V Machine Model 300V Differential Input Voltage t Supply Voltage Supply Voltage V V5 16V Output Short Circuit to V Note 8 Output Short Circuit to V Note 3 Lead Temperature soldering 10 sec 260 C Current at Output Pin 18 mA Current at Input Pin t5 mA Current at Power Supply Pin 35 mA DC Electrical Characteristics Storage Temperature Range 65 C to 150 C Junction Temperature Note 4 150 C Operating Ratings Note 1 Supply Voltage 2 0V to 15 5V Temperature Range 6035 and LMC6036l Thermal Resistance 0 AV CHT lt 85 C MSOP 8 pin Mini Surface Mount 230 C W M Package 8 pin Surface Mount 175 C W M Package 14 pin Surface Mount 127 C W MTC Package 14 pin TSSOP 137 C W BP 8 Bump micro SMD Package 220 C W Unless otherwise specified all limits guaranteed for T 25 C V 2 7V V OV Vom 1 0V Vo 1 35V and R gt 1 Boldface limits apply at the temperature extremes LMC6035I Symbol Parameter Conditions LMC6036l Units Limit Note 6 Vos Input O
14. Cx Improve Capacitive Load Tolerance Capacitive load driving capability is enhanced by using a pull up resistor to V Figure 11 Typically a pull up resistor con ducting 500 pA or more will significantly improve capacitive load responses The value of the pull up resistor must be de termined based on the current sinking capability of the ampli fier with respect to the desired output swing Open loop gain of the amplifier can also be affected by the pull up resistor see Electrical Characteristics V I DS012830 6 FIGURE 11 Compensating for Large Capacitive Loads with a Pull Up Resistor www national com Physical Dimensions inches millimeters unless otherwise noted 0 150 0 157 3 810 3 988 0 010 0 020 45 0 254 0 508 8 A 10 102 0 008 OO Leap trs 0 203 0 254 se 016 70 050 ALL LEADS ALL LEADS 0 189 0 197 4 800 5 004 8 7 6 5 0 228 0 244 5 791 6 198 0 010 max 0 254 1 2 3 4 x IDENT Tn 0 053 0 069 1 346 1 753 I 0 004 0 010 0 102 0 254 pote SEATING D PLANE 0 014 0 356 E 20 014 0 020 1 270 DE 356 0 508 TYP 0 008 SUO 0 203 REV H 8 Lead 0 150 Wide Molded Small Outline Package JEDEC NS Package Number M08A 15 www national com 9 099IN 1 5 090W1 LMC6035 LMC6036 Physica
15. OMMEND NON SOLDER MASK DEFINED LANDING PAD 4 PIN 1 IS ESTABLISHED BY LOWER LEFT CORNER WITH RESPECT TO TEXT ORIENTATION PINS ARE NUMBERED COUNTERCLOCKWISE 5 XXX IN DRAWING NUMBER REPRESENTS PACKAGE SIZE VARIATION WHERE X1 IS PACKAGE WIDTH X2 IS PACK AGE LENGTH AND X3 IS PACKAGE HEIGHT 6 REFERENCE JEDEC REGISTRATION MO 211 VARIATION BC 8 Bump micro SMD NS Package Number X 1 412 X 1 412 X 0 850 19 www national com 9 099IN 1 5 090W1 LMC6035 LMC6036 Low Power 2 7V Single Supply CMOS Operational Amplifiers LIFE SUPPORT POLICY Notes 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 2 A critical component is any component of a life 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 National Semiconductor Corporation Europe Americas Fax 49 0 1 80 530 85 86 Tel 1 800 272 9959 Email europe support nsc com Fax 1 800 737 7018 Deutsch Tel 49 0 1 80 530 85 85 Email support nsc com English T
16. These values provide a 1 Hz cutoff frequency but they can be easily scaled for a desired cutoff frequency f The bold component values of Figure 5 provide a cutoff frequency of 3 kHz An example of the scal ing procedure follows Figure 5 0 7071F Input 2 6 8 nF 1 414F LI normalized values Input requires DC offset DS012830 48 FIGURE 5 2 Pole 3 kHz Active Sallen and Key Lowpass Filter with Butterworth Response 1 2 1 1 Low Pass Frequency Scaling Procedure The actual component values represented in bold of Figure 5 were obtained with the following scaling procedure 1 First determine the frequency scaling factor FSF for the desired cutoff frequency Choosing f at 3 KHz pro vides the following FSF computation FSF 2 x 3 kHz desired cutoff 18 84 x 10 2 Then divide all of the normalized capacitor values by the FSF as follows C1 CNormalizeay FSF C1 0 707 18 84 x 10 37 93 x 1079 C2 1 414 18 84 x 10 75 05 x 10 6 C1 and C2 prior to impedance scaling 3 Last choose an impedance scaling factor Z This Z factor can be calculated from a standard value for C2 Then Z can be used to determine the remaining compo nent values as follows Z 2 2 75 05 x 10 9 6 8 nF 8 4k C1 172 37 93 x 1079 8 4k 4 52 nF Standard capacitor value chosen for C1 is 4 7 nF R1 R1 normalizes X Z 10 x 8 4k 8 4
17. eatures Typical Unless Otherwise Noted m LMC6035 in micro SMD Package Guaranteed 2 7V 3V 5V and 15V Performance m Specified for 2 and 6000 Loads m Wide Operating Range 2 0V to 15 5V m Ultra Low Input Current 20 fA m Rail to Rail Output Swing 96000 200 mV from either rail at 2 7V 100 kQ 5 mV from either rail at 2 7V m High Voltage Gain 126dB m Wide Input Common Mode Voltage Range 0 1V to 2 3V at Vs 2 7V m Low Distortion 0 01 at 10 kHz Applications Filters High Impedance Buffer or Preamplifier Battery Powered Electronics Medical Instrumentation 8 Bump micro SMD OUTPUT A OUTPUT B INVERTING INPUT A INVERTING INPUT B NON INVERTING INPUT A NON INVERTING INPUT B DS012830 65 Top View Bump Side Down 2000 National Semiconductor Corporation DS012830 www national com sJeuyidury jeuonejedo soo iddns ajbuls AZ 96099 1 5 0909W1 LMC6035 LMC6036 Ordering Information Package Temperature Transport NSC Range Media Drawing Industrial 40 C to 85 C 8 pin Small Outline SO LMC6035IM Rails LMC60351MX 2 5k Units MO8A Tape and Reel 8 pin Mini Small Outline LMC6035IMM 1k Units Tape MSOP and Reel LMC6035IMMX 3 5k Units Reel 14 pin Small Outline SO LMC6036IM Rails LMC6036IMX 2 5k Units M14A Tape and Reel 14 pin Thin Shrink Small LMC6036IMT Rails Outline TSSOP LMC6036IMTX 2 5k Units MT
18. el Francais Tel www national com Italiano Tel 49 0 1 80 532 78 32 49 0 1 80 532 93 58 49 0 1 80 534 16 80 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
19. ffset Voltage 5 mV max TCVos Input Offset Voltage Average Drift lin Input Current Note 11 pA max los Input Offset Current Note 11 pA max Rin Input Resistance Tera CMRR Common Mode 0 7V Vom 12 7V dB Rejection Ratio Vt 15V min PSRR Positive Power Supply 5V lt Vi lt 15V dB Rejection Ratio Vo 2 5V min PSRR Negative Power Supply OV lt lt 10V dB Rejection Ratio Vo 2 5V 5V min Vom Input Common Mode Vt 2 7V V Voltage Range For CMRR gt 40 dB max V min Vt 3V V For CMRR 2 40 dB max V min V 5V V For CMRR 2 50 dB max V 3 9 min V 15V 0 5 0 2 V For CMRR 2 50 dB max 14 4 14 0 V 13 7 min www national com 9 099IN 1 5 090W1 LMC6035 LMC6036 DC Electrical Characteristics continued Unless otherwise specified all limits guaranteed for T 25 C V 2 7V V OV Vem 1 0V Vo 1 35V and gt 1 Boldface limits apply at the temperature extremes LMC6035I Symbol Parameter Conditions ms 5 LMC60361 Units Limit Note 6 Ay Large Signal Voltage Gain Sourcing 1000 100 V mV Note 7 75 min Sinking 250 25 V mV 20 min R 2 Sourcing 2000 V mV Sinking 500 V mV Vo Output Swing V 22 7N 2 5 2 0 V R 6000 to 1 35V 1 8 min 0 2 0 5 V 0 7 max 2 7V 2 62 2 4 V 2 to 1 35V 2 2 min 0 07 0 2 V 0 4 max 15V 14 5 13 5 V R 6000 to 7 5V 13 0 min 0 36 1 25 V 1 50 max V 215V 14 8 14 2 V R
20. its applied load appears capacitive The threshold of oscillation varies both with load and circuit gain The configu ration most sensitive to oscillation is a unity gain follower See the Typical Performance Characteristics The load capacitance interacts with the op amp s output re sistance to create an additional pole If this pole frequency is sufficiently low it will degrade the op amp s phase margin so that the amplifier is no longer stable at low gains As shown in Figure 10 the addition of a small resistor 500 1000 series with the op amp s output and a capacitor 5 pF 10 pF from inverting input to output pins returns the phase margin to safe value without interfering with lower frequency circuit operation Thus larger values of ca pacitance can be tolerated without oscillation Note that in all cases the output will ring heavily when the load capacitance is near the threshold for oscillation 1 4 Micro SMD Considerations Contrary to what might be guessed the micro SMD package does not follow the trend of smaller packages having higher thermal resistance LMC6035 in micro SMD has thermal re sistance of 220 C W compared to 230 C W in MSOP Even when driving a 600Q load and operating from 7 5V sup plies the maximum temperature raise will be under 4 5 C For application information specific to micro SMD see Appli cation note AN 1112 100ka Cx 10 pF DS012830 5 FIGURE 10 Rx
21. l Dimensions inches millimeters unless otherwise noted Continued 0 118 0 004 8 3 0 1 8 5 1 1 0 189 0 118 0 004 0 193 0 004 4 8 4 940 1 3 0 1 e 0 040 1 02 TYP Po 3 0 016 TR m 0 0256 0 41 hes 0 0256 TYP LAND PATTERN RECOMMENDATION 0 65 0 005 Rr TYP 0 13 GAGE 043 0 005 PLANE x 6 13 c3 0 002 0 05 0 0120 7 0 021 0 005 310 10 TYP gt 0 53 0 12 09 69 0 002 0 006 20 05 034 0 0375 SEATING PLANE 0 06 0 15 0 86 gt 0 002 0 05 8 c 0 007 0 002 0 18 0 05 D MUAOBA REV B 8 Lead 0 150 Wide Molded Mini Small Outline Package JEDEC NS Package Number MUAO8A www national com 16 Physical Dimensions inches millimeters unless otherwise noted Continued 0 150 0 157 3 810 3 988 lt 0 010 0 020 0 254 0 508 2 0335 0344 2 8 509 8 738 12 0 9 0 008 0 010 0 203 0 254 ALL LEADS 0 004 0 102 ALL LEAD TIPS 0 228 0 244 5 791 qum LEADNO 1 IDENT 1 2 3 0 053 0 069 1 346 1 753 8 MAX TYP ALL LEADS SEATING WW 7T i Lot 0 016 0 050 035 0406 1 270 TYP ALL LEADS 14 Lead 0 150 Wide Molded Small Outline Package JEDEC NS Package Number M14A 0 010 wax 0 254
22. l Response OUTPUT SIGNAL INPUT SIGNAL 50 mV div TIME 1 us div DS012830 31 Inverting Large Signal Response OUTPUT SIGNAL 500 mV div INPUT SIGNAL TIME 1 us div DS012830 26 Inverting Small Signal Response T 859 bct e a i E 83 gt E wok lt uy e e X TIME 1 us div DS012830 29 Stability vs Capacitive Load 1000 Ay UNSTABLE Yo EN ISN R 6000 100 CAPACITIVE LOAD pF 25 OVERSHOOT 10 12 0 8 04 0 04 08 12 Your V DS012830 38 www national com 9 090IN 1 5 090W 1 LMC6035 LMC6036 Typical Performance Characteristics Unless otherwise specified Vs 2 7V single supply Ta 25 Continued Stability vs Capacitive Load Stability vs Capacitive Load Stability vs Capacitive Load
23. nse OUTPUT SIGNAL 50 mV div INPUT SIGNAL TIME 1 us div DS012830 23 www national com Typical Performance Characteristics unless otherwise specified Vs 2 7V single supply Ta 25 C Continued Non Inverting Small Signal Response a 2 a 2 gt 5 gt 1 o0 10 lt L a zi a z TIME 1 us div DS012830 24 Inverting Large Signal Response T 259 2 0 e i 5 EE QA E gt SL zo L e E TIME 1 us div DS012830 27 Inverting Small Signal Response Sj Ty 259 e 2 E m o x a lt N z 5 L e a z TIME 1 us div DS012830 30 Non Inverting Large Signal Response OUTPUT SIGNAL INPUT SIGNAL 50 mV div TIME 1 us div DS012830 25 Inverting Large Signal Response i 2 o m EE on gt e 0 e TIME 1 us div 05012830 28 Inverting Small Signa
24. op amps with about 6000 of AC load at 1 kHz Capacitor C1 functions to block DC from the low winding resistance of T1 Although the value of C1 is relatively high its load reactance Xc is negligible compared to inductive reactance X of T1 Cl qu 10 uF 6000 to 6000 DS012830 44 FIGURE 1 Differential Driver The circuit in Figure 1 consists of one input signal and two output signals U1A amplifies the input with an inverting gain of 2 while the U1B amplifies the input with a noninverting gain of 2 Since the two outputs are 180 out of phase with each other the gain across the differential output is 4 As the differential output swings between the supply rails one of the op amps sources the current to the load while the other op amp sinks the current How good a CMOS op amp can sink or source a current is an important factor in determining its output swing capability The output stage of the LMC6035 6 like many op sources and sinks output current through two complementary transistors in series This totem pole ar rangement translates to a channel resistance Rason at each supply rail which acts to limit the output swing Most CMOS op amps are able to swing the outputs very close to the rails except however under the difficult conditions of low supply voltage and heavy load The LMC6035 6 exhibits ex ceptional output swing capability under these conditions The scope photos of Figure 2 and Figure
25. oth the top and bottom of the PC board This PC foil must then be connected to a voltage which is at the same voltage as the amplifier inputs since no leakage current can flow between two points at the same po tential For example a PC board trace to pad resistance of 10120 which is normally considered a very large resistance could leak 5 pA if the trace were a 5V bus adjacent to the pad of an input This would cause a 100 times degradation from the amplifiers actual performance However if a guard ring is held within 5 mV of the inputs then even a resistance of 10110 would cause only 0 05 pA of leakage current or per haps a minor 2 1 degradation of the amplifiers perfor mance See Figure 9a b c for typical connections of guard rings for standard op amp configurations If both inputs are active and at high impedance the guard can be tied to ground and still provide some protection see Figure 9 d INB INB OUTB V l oj Guard Ring DS012830 7 FIGURE 8 Example using the LMC6036 of Guard Ring in P C Board Layout 13 www national com 9 090N 1 S 090W 1 LMC6035 LMC6036 1 0 Application Notes continued OUTPUT DS012830 8 DS012830 9 b Non Inverting Amplifier INPUT 05012830 10 Follower 5012830 11 Howland Current Pump FIGURE 9 Guard Ring Connections 1 3 1 CAPACITIVE LOAD TOLERANCE Like many other op amps the LMC6035 6 may oscillate when
26. selection for the DABP filter is performed as fol lows 1 First choose a center frequency f Figure 7 represents component values that were obtained from the following computation for a center frequency of 1 kHz R2 1 2 nf C Given f 1 kHz and C chosen 6 8 NF R2 1 2x x kHz x 6 8 nF 23 4 Chosen standard value is 23 7 2 Then compute R1 for a desired f BW as follows R1 Q x R2 Choosing a Q of 100 R1 100 x 23 7 kQ 2 37 1 3 PRINTED CIRCUIT BOARD LAYOUT FOR HIGH IMPEDANCE WORK It is generally recognized that any circuit which must operate with lt 1000 pA of leakage current requires special layout of the PC board If one wishes to take advantage of the ultra low bias current of the LMC6035 6 typically 0 04 pA it is essential to have an excellent layout Fortunately the techniques for obtaining low leakages are quite simple First the user must not ignore the surface leakage of the PC board even though it may at times appear acceptably low Under conditions of high humidity dust or contamination the surface leakage will be appreciable To minimize the effect of any surface leakage lay out a ring of foil completely surrounding the LMC6035 or LMC6036 in puts and the terminals of capacitors diodes conductors re sistors relay terminals etc connected to the op amp s in puts See Figure 8 To have a significant effect guard rings should be placed on b
27. unction temperature of 150 C Output currents in excess of 30 mA over long term may adversely affect reliabilty Note 4 The maximum power dissipation is a function of T jm and TA The maximum allowable power dissipation at any ambient temperature is T may All numbers apply for packages soldered directly onto PC board with no air flow Note 5 Typical Values represent the most likely parametric norm or one sigma value Note 6 All limits are guaranteed by testing or statistical analysis Note 7 V 15V Vom 7 5V R connected to 7 5V For Sourcing tests 7 5V lt Vo lt 11 5V For Sinking tests 3 5V lt Vo lt 7 5V Note 8 Do not short circuit output to V when V is greater than 13V or reliability will be adversely affected Note 9 V 15V Connected as voltage follower with 10V step input Number specified is the slower of the positive and negative slew rates Note 10 Input referred V 15V and RI 100 connected to 7 5V Each amp excited in turn with 1 kHz to produce Vo 12 Vpp Note 11 Guaranteed by design 5 www national com 9 090N 1 S 090W 1 LMC6035 LMC6036 0 7 0 6 Supply Current vs Supply Voltage Per Amplifier 0 5 0 4 0 3 Supply Current mA 0 2 0 1 4 6 8 10 12 14 16 Supply Voltage V DS012830 52 Sourcing Current vs Output Voltage

National Semiconductor LMC6035/LMC6036 Low Power 2.7V Single Supply CMOS Operational Amplifiers handbook

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