LMC6462, LMC6464 www.ti.com SNOS725D – MAY 1999 – REVISED MARCH 2013 LMC6462 Dual/LMC6464 Quad Micropower, Rail-to-Rail Input and Output CMOS Operational Amplifier Check for Samples: LMC6462, LMC6464 FEATURES DESCRIPTION • • • • The LMC6462/4 is a micropower version of the popular LMC6482/4, combining Rail-to-Rail Input and Output Range with very low power consumption. 1 2 • • • (Typical Unless Otherwise Noted) Ultra Low Supply Current 20 μA/Amplifier Ensured Characteristics at 3V and 5V Rail-to-Rail Input Common-Mode Voltage Range Rail-to-Rail Output Swing – (within 10 mV of rail, VS = 5V and RL = 25 kΩ) Low Input Current 150 fA Low Input Offset Voltage 0.25 mV The LMC6462/4, with ensured specifications at 3V and 5V, is especially well-suited for low voltage applications. A quiescent power consumption of 60 μW per amplifier (at VS = 3V) can extend the useful life of battery operated systems. The amplifier's 150 fA input current, low offset voltage of 0.25 mV, and 85 dB CMRR maintain accuracy in battery-powered systems. APPLICATIONS • • • • • The LMC6462/4 provides an input common-mode voltage range that exceeds both rails. The rail-to-rail output swing of the amplifier, ensured for loads down to 25 kΩ, assures maximum dynamic signal range. This rail-to-rail performance of the amplifier, combined with its high voltage gain makes it unique among rail-to-rail amplifiers. The LMC6462/4 is an excellent upgrade for circuits using limited commonmode range amplifiers. Battery Operated Circuits Transducer Interface Circuits Portable Communication Devices Medical Applications Battery Monitoring Figure 1. 8-Pin PDIP/SOIC – Top View (See Package Number P or D) Figure 2. 14-Pin PDIP/SOIC – Top View (See Package Number NFF0014A or D) 10: Gain Trim 191: 10k, 0.1% 9.95k - 50: CMRR Trim A1 10k, 0.1% 10k, 0.1% - VCM + 1/2VD A2 VOUT = 100VD + VCM - 1/2VD + Figure 3. Low-Power Two-Op-Amp Instrumentation Amplifier 1 2 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 1999–2013, Texas Instruments Incorporated LMC6462, LMC6464 SNOS725D – MAY 1999 – REVISED MARCH 2013 www.ti.com These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. Absolute Maximum Ratings (1) (2) (3) ESD Tolerance (4) 2.0 kV Differential Input Voltage ±Supply Voltage (V+) + 0.3V, (V−) − 0.3V Voltage at Input/Output Pin − + Supply Voltage (V − V ) 16V Current at Input Pin (5) ±5 mA Current at Output Pin (6) (7) ±30 mA Current at Power Supply Pin 40 mA Lead Temp. (Soldering, 10 sec.) 260°C −65°C to +150°C Storage Temperature Range Junction Temperature (8) (1) (2) (3) (4) (5) (6) (7) (8) 150°C 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 ensured. For ensured specifications and the test conditions, see the Electrical Characteristics. For specified Military Temperature Range parameters see RETSMC6462/4X. If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/Distributors for availability and specifications. Human body model, 1.5 kΩ in series with 100 pF. All pins rated per method 3015.6 of MIL-STD-883. This is a class 2 device rating. Limiting input pin current is only necessary for input voltages that exceed absolute maximum input voltage ratings. 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. Do not short circuit output to V+, when V+ is greater than 13V or reliability will be adversely affected. The maximum power dissipation is a function of TJ(MAX), θJA, and TA. The maximum allowable power dissipation at any ambient temperature is PD = (TJ(MAX) − TA)/θJA. All numbers apply for packages soldered directly into a PC board. Operating Ratings 3.0V ≤ V+ ≤ 15.5V Supply Voltage Junction Temperature Range Thermal Resistance (θJA) −55°C ≤ TJ ≤ +125°C LMC6462AM, LMC6464AM LMC6462AI, LMC6464AI −40°C ≤ TJ ≤ +85°C LMC6462BI, LMC6464BI −40°C ≤ TJ ≤ +85°C P Package, 8-Pin PDIP 115°C/W D Package, 8-Pin SOIC 193°C/W NFF Package, 14-Pin PDIP 81°C/W D Package, 14-Pin SOIC (1) 126°C/W 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 ensured. For ensured specifications and the test conditions, see the Electrical Characteristics. 5V DC Electrical Characteristics Unless otherwise specified, all limits ensured for TJ = 25°C, V+ = 5V, V− = 0V, VCM = VO = V+/2 and RL > 1M. Boldface limits apply at the temperature extremes. Typ (1) Symbol VOS Parameter Input Offset Voltage TCVOS Input Offset Voltage Average Drift IB Input Current (1) (2) (3) 2 Conditions 0.25 LMC6462AI LMC6464AI Limit (2) LMC6462BI LMC6464BI Limit (2) LMC6462AM LMC6464AM Limit (2) 0.5 3.0 0.5 mV 1.2 3.7 1.5 max μV/°C 1.5 See (3) 0.15 Units 10 10 200 pA max Typical Values represent the most likely parametric norm. All limits are specified by testing or statistical analysis. Specified limits are dictated by tester limitations and not device performance. Actual performance is reflected in the typical value. Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 LMC6462, LMC6464 www.ti.com SNOS725D – MAY 1999 – REVISED MARCH 2013 5V DC Electrical Characteristics (continued) Unless otherwise specified, all limits ensured for TJ = 25°C, V+ = 5V, V− = 0V, VCM = VO = V+/2 and RL > 1M. Boldface limits apply at the temperature extremes. Typ (1) Symbol Parameter IOS Input Offset Current CIN Common-Mode Input Capacitance RIN Input Resistance CMRR Common Mode Rejection Ratio +PSRR −PSRR VCM Conditions See (3) 0.075 85 0V ≤ VCM ≤ 5.0V V+ = 5V 85 Positive Power Supply Rejection Ratio 5V ≤ V+ ≤ 15V, V− = 0V, VO = 2.5V 85 Negative Power Supply Rejection Ratio −5V ≤ V− ≤ −15V, V+ = 0V, VO = −2.5V 85 Input Common-Mode Voltage Range V+ = 5V For CMRR ≥ 50 dB −0.2 V+ = 15V For CMRR ≥ 50 dB −0.2 15.30 RL = 100 kΩ (4) Sourcing Sinking RL = 25 kΩ (4) Sourcing Sinking VO Output Swing Units 5 5 100 pA max pF Tera Ω V+ = 5V RL = 100 kΩ to V+/2 V+ = 5V RL = 25 kΩ to V+/2 70 67 62 65 70 65 70 67 62 65 70 65 70 67 62 65 70 65 70 67 62 65 −0.10 −0.10 −0.10 0.00 0.00 0.00 5.25 5.25 5.25 5.00 5.00 5.00 −0.15 −0.15 −0.15 0.00 0.00 0.00 15.25 15.25 15.25 15.00 15.00 15.00 dB min dB min dB min V max V min V max V min 400 V/mV min 2500 V/mV min 200 V/mV min 4.995 4.990 14.990 0.010 V+ = 15V RL = 25 kΩ to V+/2 65 V/mV min 0.010 V+ = 15V RL = 100 kΩ to V+/2 70 3000 0.005 14.965 0.025 (4) LMC6462AM LMC6464AM Limit (2) >10 0V ≤ VCM ≤ 15.0V, V+ = 15V Large Signal Voltage Gain LMC6462BI LMC6464BI Limit (2) 3 5.30 AV LMC6462AI LMC6464AI Limit (2) 4.990 4.950 4.990 4.980 4.925 4.970 0.010 0.050 0.010 0.020 0.075 0.030 4.975 4.950 4.975 4.965 4.850 4.955 0.020 0.050 0.020 0.035 0.150 0.045 14.975 14.950 14.975 14.965 14.925 14.955 0.025 0.050 0.025 0.035 0.075 0.050 14.900 14.850 14.900 14.850 14.800 14.800 0.050 0.100 0.050 0.150 0.200 0.200 V min V max V min V max V min V max V min V max V+ = 15V, VCM = 7.5V and RL connected to 7.5V. For Sourcing tests, 7.5V ≤ VO ≤ 11.5V. For Sinking tests, 3.5V ≤ VO ≤ 7.5V. Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 Submit Documentation Feedback 3 LMC6462, LMC6464 SNOS725D – MAY 1999 – REVISED MARCH 2013 www.ti.com 5V DC Electrical Characteristics (continued) Unless otherwise specified, all limits ensured for TJ = 25°C, V+ = 5V, V− = 0V, VCM = VO = V+/2 and RL > 1M. Boldface limits apply at the temperature extremes. Typ (1) Symbol ISC Output Short Circuit Current V+ = 5V ISC Output Short Circuit Current V+ = 15V IS (5) Parameter Supply Current Conditions Sourcing, VO = 0V LMC6462AI LMC6464AI Limit (2) LMC6462BI LMC6464BI Limit (2) LMC6462AM LMC6464AM Limit (2) 19 19 19 15 15 15 22 22 22 17 17 17 24 24 24 17 17 17 55 55 55 45 45 45 55 55 55 70 70 75 110 110 110 140 140 150 60 60 27 Sinking, VO = 5V 27 Sourcing, VO = 0V 38 Sinking, VO = 12V (5) 75 Dual, LMC6462 V+ = +5V, VO = V+/2 40 Quad, LMC6464 V+ = +5V, VO = V+/2 80 Dual, LMC6462 V+ = +15V, VO = V+/2 50 60 70 70 75 Quad, LMC6464 V+ = +15V, VO = V+/2 90 120 120 120 140 140 150 Units mA min mA min mA min mA min μA max μA max μA max μA max Do not short circuit output to V+, when V+ is greater than 13V or reliability will be adversely affected. 5V AC Electrical Characteristics Unless otherwise specified, all limits ensured for TJ = 25°C, V+ = 5V, V− = 0V, VCM = VO = V+/2 and RL > 1M. Boldface limits apply at the temperature extremes. Typ (1) Symbol SR Parameter Slew Rate GBW Gain-Bandwidth Product φm Gm Conditions See (3) V+ = 15V 28 LMC6462AI LMC6464AI Limit (2) LMC6462BI LMC6464BI Limit (2) LMC6462AM LMC6464AM Limit (2) 15 15 15 8 8 8 Units V/ms min 50 kHz Phase Margin 50 Deg Gain Margin 15 dB Amp-to-Amp Isolation See (4) 130 dB en Input-Referred Voltage Noise f = 1 kHz VCM = 1V 80 nV/√Hz in Input-Referred Current Noise f = 1 kHz 0.03 pA/√Hz (1) (2) (3) (4) 4 Typical Values represent the most likely parametric norm. All limits are specified by testing or statistical analysis. V+ = 15V. Connected as Voltage Follower with 10V step input. Number specified is the slower of either the positive or negative slew rates. Input referred, V+ = 15V and RL = 100 kΩ connected to 7.5V. Each amp excited in turn with 1 kHz to produce VO = 12 VPP. Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 LMC6462, LMC6464 www.ti.com SNOS725D – MAY 1999 – REVISED MARCH 2013 3V DC Electrical Characteristics Unless otherwise specified, all limits ensured for TJ = 25°C, V+ = 3V, V− = 0V, VCM = VO = V+/2 and RL > 1M. Boldface limits apply at the temperature extremes. Typ (1) Symbol VOS Parameter Conditions Input Offset Voltage 0.9 LMC6462AI LMC6464AI Limit (2) LMC6462BI LMC6464BI Limit (2) LMC6462AM LMC6464AM Limit (2) 2.0 3.0 2.0 2.7 3.7 3.0 Units mV max TCVOS Input Offset Voltage Average Drift IB Input Current See (3) 0.15 10 10 200 pA IOS Input Offset Current See (3) 0.075 5 5 100 pA CMRR Common Mode Rejection Ratio 0V ≤ VCM ≤ 3V 74 60 60 60 dB min PSRR Power Supply Rejection Ratio 3V ≤ V+ ≤ 15V, V− = 0V 80 60 60 60 dB min VCM Input Common-Mode Voltage Range For CMRR ≥ 50 dB −0.10 0.0 0.0 0.0 V max 3.0 3.0 3.0 3.0 2.95 2.9 2.9 2.9 V min 0.15 0.1 0.1 0.1 V max Dual, LMC6462 VO = V+/2 40 55 55 55 μA 70 70 70 Quad, LMC6464 VO = V+/2 80 110 110 110 140 140 140 VO Output Swing IS (1) (2) (3) Supply Current μV/°C 2.0 RL = 25 kΩ to V+/2 V min μA max Typical Values represent the most likely parametric norm. All limits are specified by testing or statistical analysis. Specified limits are dictated by tester limitations and not device performance. Actual performance is reflected in the typical value. 3V AC Electrical Characteristics Unless otherwise specified, V+ = 3V, V− = 0V, VCM = VO = V+/2 and RL > 1M. Boldface limits apply at the temperature extremes. Typ (1) Symbol Parameter SR Slew Rate GBW Gain-Bandwidth Product (1) (2) (3) Conditions See (3) LMC6462AI LMC6464AI Limit (2) LMC6462BI LMC6464BI Limit (2) LMC6462AM LMC6464AM Limit (2) Units 23 V/ms 50 kHz Typical Values represent the most likely parametric norm. All limits are specified by testing or statistical analysis. Connected as Voltage Follower with 2V step input. Number specified is the slower of either the positive or negative slew rates. Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 Submit Documentation Feedback 5 LMC6462, LMC6464 SNOS725D – MAY 1999 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics VS = +5V, Single Supply, TA = 25°C unless otherwise specified 6 Supply Current vs. Supply Voltage Sourcing Current vs. Output Voltage Figure 4. Figure 5. Sourcing Current vs. Output Voltage Sourcing Current vs. Output Voltage Figure 6. Figure 7. Sinking Current vs. Output Voltage Sinking Current vs. Output Voltage Figure 8. Figure 9. Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 LMC6462, LMC6464 www.ti.com SNOS725D – MAY 1999 – REVISED MARCH 2013 Typical Performance Characteristics (continued) VS = +5V, Single Supply, TA = 25°C unless otherwise specified Sinking Current vs. Output Voltage Input Voltage Noise vs Frequency Figure 10. Figure 11. Input Voltage Noise vs. Input Voltage Input Voltage Noise vs. Input Voltage Figure 12. Figure 13. Input Voltage Noise vs. Input Voltage ΔVOS vs CMR Figure 14. Figure 15. Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 Submit Documentation Feedback 7 LMC6462, LMC6464 SNOS725D – MAY 1999 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (continued) VS = +5V, Single Supply, TA = 25°C unless otherwise specified 8 Input Voltage vs. Output Voltage Open Loop Frequency Response Figure 16. Figure 17. Open Loop Frequency Response vs. Temperature Gain and Phase vs. Capacitive Load Figure 18. Figure 19. Slew Rate vs. Supply Voltage Non-Inverting Large Signal Pulse Response Figure 20. Figure 21. Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 LMC6462, LMC6464 www.ti.com SNOS725D – MAY 1999 – REVISED MARCH 2013 Typical Performance Characteristics (continued) VS = +5V, Single Supply, TA = 25°C unless otherwise specified Non-Inverting Large Signal Pulse Response Non-Inverting Large Signal Pulse Response Figure 22. Figure 23. Non-Inverting Small Signal Pulse Response Non-Inverting Small Signal Pulse Response Figure 24. Figure 25. Non-Inverting Small Signal Pulse Response Inverting Large Signal Pulse Response Figure 26. Figure 27. Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 Submit Documentation Feedback 9 LMC6462, LMC6464 SNOS725D – MAY 1999 – REVISED MARCH 2013 www.ti.com Typical Performance Characteristics (continued) VS = +5V, Single Supply, TA = 25°C unless otherwise specified Inverting Large Signal Pulse Response Inverting Large Signal Pulse Response Figure 28. Figure 29. Inverting Small Signal Pulse Response Inverting Small Signal Pulse Response Figure 30. Figure 31. Inverting Small Signal Pulse Response Figure 32. 10 Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 LMC6462, LMC6464 www.ti.com SNOS725D – MAY 1999 – REVISED MARCH 2013 APPLICATION INFORMATION Input Common-Mode Voltage Range The LMC6462/4 has a rail-to-rail input common-mode voltage range. Figure 33 shows an input voltage exceeding both supplies with no resulting phase inversion on the output. Figure 33. An Input Voltage Signal Exceeds the LMC6462/4 Power Supply Voltage with No Output Phase Inversion The absolute maximum input voltage at V+ = 3V is 300 mV beyond either supply rail at room temperature. Voltages greatly exceeding this absolute maximum rating, as in Figure 34, can cause excessive current to flow in or out of the input pins, possibly affecting reliability. The input current can be externally limited to ±5 mA, with an input resistor, as shown in Figure 35. Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 Submit Documentation Feedback 11 LMC6462, LMC6464 SNOS725D – MAY 1999 – REVISED MARCH 2013 www.ti.com Figure 34. A ±7.5V Input Signal Greatly Exceeds the 3V Supply in Figure 35 Causing No Phase Inversion Due to RI Figure 35. Input Current Protection for Voltages Exceeding the Supply Voltage Rail-to-Rail Output The approximated output resistance of the LMC6462/4 is 180Ω sourcing, and 130Ω sinking at VS = 3V, and 110Ω sourcing and 83Ω sinking at VS = 5V. The maximum output swing can be estimated as a function of load using the calculated output resistance. Capacitive Load Tolerance The LMC6462/4 can typically drive a 200 pF load with VS = 5V at unity gain without oscillating. The unity gain follower is the most sensitive configuration to capacitive load. Direct capacitive loading reduces the phase margin of op-amps. The combination of the op-amp's output impedance and the capacitive load induces phase lag. This results in either an underdamped pulse response or oscillation. Capacitive load compensation can be accomplished using resistive isolation as shown in Figure 36. If there is a resistive component of the load in parallel to the capacitive component, the isolation resistor and the resistive load create a voltage divider at the output. This introduces a DC error at the output. 12 Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 LMC6462, LMC6464 www.ti.com SNOS725D – MAY 1999 – REVISED MARCH 2013 Figure 36. Resistive Isolation of a 300 pF Capacitive Load Figure 37. Pulse Response of the LMC6462 Circuit Shown in Figure 36 Figure 37 displays the pulse response of the LMC6462/4 circuit in Figure 36. Another circuit, shown in Figure 38, is also used to indirectly drive capacitive loads. This circuit is an improvement to the circuit shown in Figure 36 because it provides DC accuracy as well as AC stability. R1 and C1 serve to counteract the loss of phase margin by feeding the high frequency component of the output signal back to the amplifiers inverting input, thereby preserving phase margin in the overall feedback loop. The values of R1 and C1 should be experimentally determined by the system designer for the desired pulse response. Increased capacitive drive is possible by increasing the value of the capacitor in the feedback loop. Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 Submit Documentation Feedback 13 LMC6462, LMC6464 SNOS725D – MAY 1999 – REVISED MARCH 2013 www.ti.com Figure 38. LMC6462 Non-Inverting Amplifier, Compensated to Handle a 300 pF Capacitive and 100 kΩ Resistive Load Figure 39. Pulse Response of LMC6462 Circuit in Figure 38 The pulse response of the circuit shown in Figure 38 is shown in Figure 39 Compensating for Input Capacitance It is quite common to use large values of feedback resistance with amplifiers that have ultra-low input current, like the LMC6462/4. Large feedback resistors can react with small values of input capacitance due to transducers, photodiodes, and circuits board parasitics to reduce phase margins. 14 Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 LMC6462, LMC6464 www.ti.com SNOS725D – MAY 1999 – REVISED MARCH 2013 Figure 40. Canceling the Effect of Input Capacitance The effect of input capacitance can be compensated for by adding a feedback capacitor. The feedback capacitor (as in Figure 40 ), CF, is first estimated by: (1) or R1 CIN ≤ R2 CF (2) which typically provides significant overcompensation. Printed circuit board stray capacitance may be larger or smaller than that of a breadboard, so the actual optimum value for CF may be different. The values of CF should be checked on the actual circuit. (Refer to the LMC660 quad CMOS amplifier data sheet for a more detailed discussion.) Offset Voltage Adjustment Offset voltage adjustment circuits are illustrated in Figure 41 and Figure 42. Large value resistances and potentiometers are used to reduce power consumption while providing typically ±2.5 mV of adjustment range, referred to the input, for both configurations with VS = ±5V. Figure 41. Inverting Configuration Offset Voltage Adjustment Figure 42. Non-Inverting Configuration Offset Voltage Adjustment SPICE Macromodel A Spice macromodel is available for the LMC6462/4. This model includes a simulation of: • Input common-mode voltage range Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 Submit Documentation Feedback 15 LMC6462, LMC6464 SNOS725D – MAY 1999 – REVISED MARCH 2013 • • • • www.ti.com Frequency and transient response GBW dependence on loading conditions Quiescent and dynamic supply current Output swing dependence on loading conditions and many more characteristics as listed on the macromodel disk. Contact the Texas Instruments Customer Response Center to obtain an operational amplifier Spice model library disk Printed-Circuit-Board Layout for High-Impedance Work It is generally recognized that any circuit which must operate with less than 1000 pA of leakage current requires special layout of the PC board. When one wishes to take advantage of the ultra-low input current of the LMC6462/4, typically 150 fA, it is essential to have an excellent layout. Fortunately, the techniques of obtaining low leakages are quite simple. First, the user must not ignore the surface leakage of the PC board, even though it may sometimes appear acceptably low, because under conditions of high humidity or 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 LMC6462's inputs and the terminals of capacitors, diodes, conductors, resistors, relay terminals, etc. connected to the op-amp's inputs, as in Figure 43. To have a significant effect, guard rings should be placed in both 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 potential. For example, a PC board trace-to-pad resistance of 1012Ω, which is normally considered a very large resistance, could leak 5 pA if the trace were a 5V bus adjacent to the pad of the input. This would cause a 30 times degradation from the LMC6462/4's actual performance. However, if a guard ring is held within 5 mV of the inputs, then even a resistance of 1011Ω would cause only 0.05 pA of leakage current. See Figure 44 through Figure 46 for typical connections of guard rings for standard op-amp configurations. Figure 43. Example of Guard Ring in P.C. Board Layout 16 Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 LMC6462, LMC6464 www.ti.com SNOS725D – MAY 1999 – REVISED MARCH 2013 Figure 44. Typical Connections of Guard Rings – Inverting Amplifier Figure 45. Typical Connections of Guard Rings – Non-Inverting Amplifier Figure 46. Typical Connections of Guard Rings – Follower The designer should be aware that when it is inappropriate to lay out a PC board for the sake of just a few circuits, there is another technique which is even better than a guard ring on a PC board: Don't insert the amplifier's input pin into the board at all, but bend it up in the air and use only air as an insulator. Air is an excellent insulator. In this case you may have to forego some of the advantages of PC board construction, but the advantages are sometimes well worth the effort of using point-to-point up-in-the-air wiring. See Figure 47. (Input pins are lifted out of PC board and soldered directly to components. All other pins connected to PC board.) Figure 47. Air Wiring Instrumentation Circuits The LMC6464 has the high input impedance, large common-mode range and high CMRR needed for designing instrumentation circuits. Instrumentation circuits designed with the LMC6464 can reject a larger range of common-mode signals than most in-amps. This makes instrumentation circuits designed with the LMC6464 an excellent choice for noisy or industrial environments. Other applications that benefit from these features include analytic medical instruments, magnetic field detectors, gas detectors, and silicon-based transducers. Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 Submit Documentation Feedback 17 LMC6462, LMC6464 SNOS725D – MAY 1999 – REVISED MARCH 2013 www.ti.com A small valued potentiometer is used in series with RG to set the differential gain of the three op-amp instrumentation circuit in Figure 48. This combination is used instead of one large valued potentiometer to increase gain trim accuracy and reduce error due to vibration. Figure 48. Low Power Three Op-Amp Instrumentation Amplifier A two op-amp instrumentation amplifier designed for a gain of 100 is shown in Figure 49. Low sensitivity trimming is made for offset voltage, CMRR and gain. Low cost and low power consumption are the main advantages of this two op-amp circuit. Higher frequency and larger common-mode range applications are best facilitated by a three op-amp instrumentation amplifier. 10: Gain Trim 191: 10k, 0.1% 9.95k - 50: CMRR Trim A1 10k, 0.1% 10k, 0.1% - VCM + 1/2VD A2 VOUT = 100VD + VCM - 1/2VD + Figure 49. Low-Power Two-Op-Amp Instrumentation Amplifier 18 Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 LMC6462, LMC6464 www.ti.com SNOS725D – MAY 1999 – REVISED MARCH 2013 TYPICAL SINGLE-SUPPLY APPLICATIONS Transducer Interface Circuits Figure 50. Photo Detector Circuit Photocells can be used in portable light measuring instruments. The LMC6462, which can be operated off a battery, is an excellent choice for this circuit because of its very low input current and offset voltage. LMC6462 as a Comparator Figure 51. Comparator with Hysteresis Figure 51 shows the application of the LMC6462 as a comparator. The hysteresis is determined by the ratio of the two resistors. The LMC6462 can thus be used as a micropower comparator, in applications where the quiescent current is an important parameter. Half-Wave and Full-Wave Rectifiers Figure 52. Half-Wave Rectifier with Input Current Protection (RI) Figure 53. Full-Wave Rectifier with Input Current Protection (RI) Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 Submit Documentation Feedback 19 LMC6462, LMC6464 SNOS725D – MAY 1999 – REVISED MARCH 2013 www.ti.com In Figure 52 Figure 53, RI limits current into the amplifier since excess current can be caused by the input voltage exceeding the supply voltage. Precision Current Source Figure 54. Precision Current Source The output current IOUT is given by: (3) Oscillators Figure 55. 1 Hz Square-Wave Oscillator For single supply 5V operation, the output of the circuit will swing from 0V to 5V. The voltage divider set up R2, R3 and R4 will cause the non-inverting input of the LMC6462 to move from 1.67V (⅓ of 5V) to 3.33V (⅔ of 5V). This voltage behaves as the threshold voltage. R1 and C1 determine the time constant of the circuit. The frequency of oscillation, fOSC is (4) where Δt is the time the amplifier input takes to move from 1.67V to 3.33V. The calculations are shown below. (5) where τ = RC = 0.68 seconds →t1 = 0.27 seconds. and (6) →t2 = 0.75 seconds 20 Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 LMC6462, LMC6464 www.ti.com SNOS725D – MAY 1999 – REVISED MARCH 2013 Then, (7) (8) = 1 Hz Low Frequency Null Figure 56. High Gain Amplifier with Low Frequency Null Output offset voltage is the error introduced in the output voltage due to the inherent input offset voltage VOS, of an amplifier. Output Offset Voltage = (Input Offset Voltage) (Gain) In the above configuration, the resistors R5 and R6 determine the nominal voltage around which the input signal, VIN should be symmetrical. The high frequency component of the input signal VIN will be unaffected while the low frequency component will be nulled since the DC level of the output will be the input offset voltage of the LMC6462 plus the bias voltage. This implies that the output offset voltage due to the top amplifier will be eliminated. Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 Submit Documentation Feedback 21 LMC6462, LMC6464 SNOS725D – MAY 1999 – REVISED MARCH 2013 www.ti.com REVISION HISTORY Changes from Revision C (March 2013) to Revision D • 22 Page Changed layout of National Data Sheet to TI format .......................................................................................................... 21 Submit Documentation Feedback Copyright © 1999–2013, Texas Instruments Incorporated Product Folder Links: LMC6462 LMC6464 PACKAGE OPTION ADDENDUM www.ti.com 27-Mar-2014 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (°C) Device Marking (4/5) LMC6462AIM NRND SOIC D 8 95 TBD Call TI Call TI -40 to 85 LMC64 62AIM LMC6462AIM/NOPB ACTIVE SOIC D 8 95 Green (RoHS & no Sb/Br) SN | CU SN Level-1-260C-UNLIM -40 to 85 LMC64 62AIM LMC6462AIMX NRND SOIC D 8 2500 TBD Call TI Call TI -40 to 85 LMC64 62AIM LMC6462AIMX/NOPB ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 LMC64 62AIM LMC6462AIN LIFEBUY PDIP P 8 40 TBD Call TI Call TI -40 to 85 LMC6462 AIN LMC6462AIN/NOPB ACTIVE PDIP P 8 40 Green (RoHS & no Sb/Br) SN | CU SN Level-1-NA-UNLIM -40 to 85 LMC6462 AIN LMC6462BIM/NOPB ACTIVE SOIC D 8 95 Green (RoHS & no Sb/Br) SN | CU SN Level-1-260C-UNLIM -40 to 85 LMC64 62BIM LMC6462BIMX/NOPB ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) SN | CU SN Level-1-260C-UNLIM -40 to 85 LMC64 62BIM LMC6462BIN LIFEBUY PDIP P 8 40 TBD Call TI Call TI -40 to 85 LMC6462 BIN LMC6462BIN/NOPB ACTIVE PDIP P 8 40 Green (RoHS & no Sb/Br) SN | CU SN Level-1-NA-UNLIM -40 to 85 LMC6462 BIN LMC6464AIM NRND SOIC D 14 55 TBD Call TI Call TI -40 to 85 LMC6464 AIM LMC6464AIM/NOPB ACTIVE SOIC D 14 55 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 LMC6464 AIM LMC6464AIMX NRND SOIC D 14 2500 TBD Call TI Call TI -40 to 85 LMC6464 AIM LMC6464AIMX/NOPB ACTIVE SOIC D 14 2500 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 LMC6464 AIM LMC6464BIM NRND SOIC D 14 55 TBD Call TI Call TI -40 to 85 LMC6464 BIM LMC6464BIM/NOPB ACTIVE SOIC D 14 55 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 LMC6464 BIM LMC6464BIMX NRND SOIC D 14 2500 TBD Call TI Call TI -40 to 85 LMC6464 BIM Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com 27-Mar-2014 Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (°C) Device Marking Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 LMC6464 BIM (4/5) LMC6464BIMX/NOPB ACTIVE SOIC D 14 2500 LMC6464BIN LIFEBUY PDIP NFF 14 25 TBD Call TI Call TI -40 to 85 LMC6464BIN LMC6464BIN/NOPB ACTIVE PDIP NFF 14 25 Green (RoHS & no Sb/Br) SN Level-1-NA-UNLIM -40 to 85 LMC6464BIN (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. Addendum-Page 2 Samples PACKAGE OPTION ADDENDUM www.ti.com 27-Mar-2014 In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 3 PACKAGE MATERIALS INFORMATION www.ti.com 23-Sep-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant LMC6462AIMX SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LMC6462AIMX/NOPB SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LMC6462BIMX/NOPB SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LMC6464AIMX SOIC D 14 2500 330.0 16.4 6.5 9.35 2.3 8.0 16.0 Q1 LMC6464AIMX/NOPB SOIC D 14 2500 330.0 16.4 6.5 9.35 2.3 8.0 16.0 Q1 LMC6464BIMX SOIC D 14 2500 330.0 16.4 6.5 9.35 2.3 8.0 16.0 Q1 LMC6464BIMX/NOPB SOIC D 14 2500 330.0 16.4 6.5 9.35 2.3 8.0 16.0 Q1 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 23-Sep-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LMC6462AIMX SOIC D 8 2500 367.0 367.0 35.0 LMC6462AIMX/NOPB SOIC D 8 2500 367.0 367.0 35.0 LMC6462BIMX/NOPB SOIC D 8 2500 367.0 367.0 35.0 LMC6464AIMX SOIC D 14 2500 367.0 367.0 35.0 LMC6464AIMX/NOPB SOIC D 14 2500 367.0 367.0 35.0 LMC6464BIMX SOIC D 14 2500 367.0 367.0 35.0 LMC6464BIMX/NOPB SOIC D 14 2500 367.0 367.0 35.0 Pack Materials-Page 2 MECHANICAL DATA NFF0014A N0014A N14A (Rev G) www.ti.com IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. 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