Sample & Buy Product Folder Support & Community Tools & Software Technical Documents LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 LMV84x CMOS Input, RRIO, Low Power, Wide Supply Range, 4.5-MHz Operational Amplifiers 1 Features 3 Description • The LMV84x devices are low-voltage and low-power operational amplifiers that operate with supply voltages ranging from 2.7 V to 12 V and have rail-torail input and output capability. Their low offset voltage, low supply current, and CMOS inputs make them ideal for high impedance sensor interface and battery-powered applications. 1 • • • • • • • • • • • • • AEC-Q100 Automotive Qualification Test Guidance With the Following: – Device Temperature Grade 1: –40°C to +125°C Ambient Operating Temperature – Device HBM ESD Classification Level 2 – Device CDM ESD Classification Level C3 Unless Otherwise Noted, Typical Values at TA = 25 °C, V+ = 5 V. Small 5-Pin SC70 Package (2.00 mm × 1.25 mm × 0.95 mm) Wide Supply Voltage Range: 2.7 V to 12 V Specified Performance at 3.3 V, 5 V and ±5 V Low Supply Current: 1 mA Per Channel Unity Gain Bandwidth: 4.5 MHz Open-Loop Gain: 133 dB Input Offset Voltage: 500 µV Maximum Input Bias Current: 0.3 pA CMRR at 112 dB and PSSR at 108 dB Input Voltage Noise: 20 nV/√Hz Temperature Range: −40°C to 125°C Rail-to-Rail Input and Output (RRIO) The single LMV841 is offered in the space-saving 5Pin SC70 package, the dual LMV842 in the 8-Pin VSSOP and 8-Pin SOIC packages, and the quad LMV844 in the 14-Pin TSSOP and 14-Pin SOIC packages. These small packages are ideal solutions for area-constrained PCBs and portable electronics. The LMV841-Q1, LMV842-Q1, and LMV844-Q1 incorporate enhanced manufacturing and support processes for the automotive market, including defect detection methodologies. Reliability qualification is compliant with the requirements and temperature grades defined in the AEC-Q100 standard. Device Information(1) PART NUMBER LMV841 LMV842 2 Applications • • • • High Impedance Sensor Interface Battery-Powered Instrumentation High Gain and Instrumentation Amplifiers DAC Buffers and Active Filters LMV844 PACKAGE BODY SIZE (NOM) SC70 (5) 2.00 mm × 1.25 mm VSSOP (8) 3.00 mm × 3.00 mm SOIC (8) 4.90 mm × 3.91 mm SOIC (14) 8.65 mm × 3.91 mm TSSOP (14) 5.00 mm × 4.40 mm (1) For all available packages, see the orderable addendum at the end of the data sheet. Typical Applications - VIN + + Active Band-Pass Filter SENSOR RS + VS + - RS - + LOAD High Impedance Sensor Interface CMOS Input Feature High-Side, Current-Sensing Rail-to-Rail Input and Output Feature Copyright © 2016, Texas Instruments Incorporated 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 www.ti.com Table of Contents 1 2 3 4 5 6 7 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Pin Configuration and Functions ......................... Specifications......................................................... 1 1 1 2 3 3 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 3 4 4 4 4 6 7 9 Absolute Maximum Ratings ...................................... ESD Ratings.............................................................. Recommended Operating Conditions....................... Thermal Information .................................................. Electrical Characteristics – 3.3 V ............................. Electrical Characteristics – 5 V ................................ Electrical Characteristics – ±5-V .............................. Typical Characteristics .............................................. Detailed Description ............................................ 15 7.1 Overview ................................................................. 15 7.2 Functional Block Diagram ....................................... 15 7.3 Feature Description................................................. 15 7.4 Device Functional Modes........................................ 16 8 Application and Implementation ........................ 20 8.1 Application Information............................................ 20 8.2 Typical Applications ................................................ 20 9 Power Supply Recommendations...................... 24 10 Layout................................................................... 24 10.1 Layout Guidelines ................................................. 24 10.2 Layout Example .................................................... 24 11 Device and Documentation Support ................. 25 11.1 11.2 11.3 11.4 11.5 11.6 Related Links ........................................................ Receiving Notification of Documentation Updates Community Resources.......................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 25 25 25 25 25 25 12 Mechanical, Packaging, and Orderable Information ........................................................... 25 4 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision G (February 2013) to Revision H Page • Added AEC-Q100 classification bullets for automotive applications in Features................................................................... 1 • Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section. ................................................................................................. 1 Changes from Revision F (February 2013) to Revision G • 2 Page Changed layout of National Semiconductor Data Sheet to TI format .................................................................................. 22 Submit Documentation Feedback Copyright © 2006–2016, Texas Instruments Incorporated Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 www.ti.com SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 5 Pin Configuration and Functions DCK Package 5-Pin SC70 Top View D or DGK Package 8-Pin SOIC and VSSOP Top View D or PW Package 14-Pin SOIC and TSSOP Top View Pin Functions PIN NAME DESCRIPTION I/O. +IN I Noninverting Input –IN I Inverting Input OUT O Output V+ P Positive Supply V– P Negative Supply 6 Specifications 6.1 Absolute Maximum Ratings See (1) (2) MIN VIN differential -300 Supply voltage (V+ – V−) Voltage at input and output pins V+ + 0.3 Input current Junction temperature Soldering information (3) Infrared or convection (20 s) Wave soldering lead temp. (10 s) Storage temperature, Tstg (1) (2) (3) −65 MAX UNIT 300 mV 13.2 V V− – 0.3 V 10 mA 150 °C 235 °C 260 °C 150 °C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office / Distributors for availability and specifications. 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 onto a PCB. Copyright © 2006–2016, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 3 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 www.ti.com 6.2 ESD Ratings VALUE V(ESD) (1) (2) Electrostatic discharge Human-body model (HBM) (1) ±2000 Charged-device model (CDM), per JEDEC specification JESD22-C101 (2) ±250 UNIT V Human-body model, applicable std. MIL-STD-883, Method 3015.7. JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. 6.3 Recommended Operating Conditions MIN MAX UNIT Temperature (1) −40 125 °C Supply voltage (V+ – V−) 2.7 12 V (1) 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 onto a PCB. 6.4 Thermal Information LMV84x THERMAL METRIC RθJA (1) (2) (1) Junction-to-ambient thermal resistance DCK (SC70) DGK (VSSOP) 5 PINS 8 PINS 8 PINS 14 PIN 14 PINS 334 205 126 110 93 (2) D (SOIC) PW (TSSOP) UNIT °C/W For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report. 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 onto a PCB. 6.5 Electrical Characteristics – 3.3 V Unless otherwise specified, all limits are ensured for TA = 25°C, V+ = 3.3 V, V− = 0 V, VCM = V+/2, and RL > 10 MΩ to V+/2. (1) PARAMETER VOS Input offset voltage TCVOS Input offset voltage drift TEST CONDITIONS at the temperature extremes Input bias current TYP (3) MAX (2) –500 ±50 500 –800 (4) –5 (4) (5) 0.3 Input offset current 40 0 V ≤ VCM ≤ 3.3 V at the temperature extremes Common-mode rejection ratio LMV842 and LMV844 0 V ≤ VCM ≤ 3.3 V at the temperature extremes PSRR Power supply rejection ratio 2.7 V ≤ V+ ≤ 12 V, VO = V+/2 CMVR Input common-mode voltage range CMRR ≥ 50 dB, at the temperature extremes CMRR 84 77 (4) (5) 4 at the temperature extremes µV µV/°C pA 112 dB 106 dB 75 108 dB 82 –0.1 UNIT fA 80 86 (3) 10 300 Common-mode rejection ratio LMV841 (2) 5 at the temperature extremes IOS (1) 800 0.5 at the temperature extremes IB MIN (2) 3.4 V 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. Limits are 100% production tested at 25°C. Limits over the operating temperature range are ensured through correlations using statistical quality control (SQC) method. Typical values represent the most likely parametric norm as determined at the time of characterization. Actual typical values may vary over time and will also depend on the application and configuration. The typical values are not tested and are not ensured on shipped production material. This parameter is ensured by design and/or characterization and is not tested in production. Positive current corresponds to current flowing into the device. Submit Documentation Feedback Copyright © 2006–2016, Texas Instruments Incorporated Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 www.ti.com SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 Electrical Characteristics – 3.3 V (continued) Unless otherwise specified, all limits are ensured for TA = 25°C, V+ = 3.3 V, V− = 0 V, VCM = V+/2, and RL > 10 MΩ to V+/2.(1) PARAMETER TEST CONDITIONS RL = 2 kΩ VO = 0.3 V to 3 V AVOL Large signal voltage gain RL = 10 kΩ VO = 0.2 V to 3.1 V at the temperature extremes MIN (2) TYP (3) 100 123 131 dB 96 52 RL = 2 kΩ to V+/2 at the temperature extremes RL = 10 kΩ to V+/2 at the temperature extremes RL = 2 kΩ to V+/2 at the temperature extremes RL = 10 kΩ to V+/2 at the temperature extremes Output swing high, (measured from V+) Sourcing VO = V+/2 VIN = 100 mV IO Output short-circuit current (6) (7) Sinking VO = V+/2 VIN = −100 mV mA 27 mA 15 0.93 IS Supply current SR Slew rate GBW Φm en Input-referred voltage noise f = 1 kHz 20 ROUT Open-loop output impedance f = 3 MHz 70 THD+N Total harmonic distortion + noise f = 1 kHz , AV = 1 RL = 10 kΩ CIN Input capacitance (6) (7) (8) Per Channel at the temperature extremes 1.5 2 AV = +1, VO = 2.3 VPP 10% to 90% (8) mV 32 15 20 at the temperature extremes mV 65 75 20 at the temperature extremes mV 100 120 33 mV 50 70 65 Output swing low, (measured from V−) 80 120 28 VO UNIT dB 96 100 at the temperature extremes MAX (2) mA 2.5 V/µs Gain bandwidth product 4.5 MHz Phase margin 67 Deg nV/ Ω 0.005% 7 pF 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 onto a PCB. Short circuit test is a momentary test. Number specified is the slower of positive and negative slew rates. Copyright © 2006–2016, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 5 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 www.ti.com 6.6 Electrical Characteristics – 5 V Unless otherwise specified, all limits are ensured for TA = 25°C, V+ = 5 V, V− = 0 V, VCM = V+/2, and RL > 10 MΩ to V+/2. (1) PARAMETER VOS Input offset voltage TCVOS Input offset voltage drift Input bias current IB TEST CONDITIONS –5 800 0.35 (4) (5) 5 0.3 40 PSRR Power supply rejection ratio 2.7V ≤ V+ ≤ 12V, VO = V+/2 CMVR Input common-mode voltage range AVOL Large signal voltage gain Output swing high, (measured from V+) RL = 10 kΩ VO = 0.2V to 4.8V at the temperature extremes SR Slew rate GBW Φm en Input-referred voltage noise 50 120 140 38 at the temperature extremes at the temperature extremes 100 70 at the temperature extremes Sinking VO = V+/2 VIN = −100 mV dB 120 70 80 20 33 20 28 0.96 mV mV mV mA 15 at the temperature extremes mV mA 15 AV = +1, VO = 4 VPP 10% to 90% (8) 133 78 V dB 96 32 at the temperature extremes Per Channel 125 at the temperature extremes pA dB 5.2 68 µV/°C dB 108 at the temperature extremes Sourcing VO = V+/2 VIN = 100 mV (6) (7) 106 96 100 µV dB 82 100 RL = 10 kΩ to V+/2 Supply current 86 at the temperature extremes 112 79 at the temperature extremes RL = 2 kΩ to V+/2 IS at the temperature extremes RL = 2 kΩ VO = 0.3V to 4.7V VO Output short-circuit current 81 UNIT fA 80 –0.2 RL = 10 kΩ to V+/2 Output swing low, (measured from V-) 86 at the temperature extremes CMRR ≥ 50 dB, at the temperature extremes RL = 2 kΩ to V+/2 IO 10 300 Input offset current 0V ≤ VCM ≤ 5V 6 500 at the temperature extremes Common-mode rejection ratio LMV842 and LMV844 (7) (8) ±50 (4) CMRR (4) (5) (6) –500 –800 0V ≤ VCM ≤ 5V (3) MAX (2) at the temperature extremes Common-mode rejection ratio LMV841 (2) TYP (3) at the temperature extremes IOS (1) MIN (2) 1.5 2 mA 2.5 V/µs Gain bandwidth product 4.5 MHz Phase margin 67 Deg f = 1 kHz 20 nV/ 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. Limits are 100% production tested at 25°C. Limits over the operating temperature range are ensured through correlations using statistical quality control (SQC) method. Typical values represent the most likely parametric norm as determined at the time of characterization. Actual typical values may vary over time and will also depend on the application and configuration. The typical values are not tested and are not ensured on shipped production material. This parameter is ensured by design and/or characterization and is not tested in production. Positive current corresponds to current flowing into the device. 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 onto a PCB. Short circuit test is a momentary test. Number specified is the slower of positive and negative slew rates. Submit Documentation Feedback Copyright © 2006–2016, Texas Instruments Incorporated Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 www.ti.com SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 Electrical Characteristics – 5 V (continued) Unless otherwise specified, all limits are ensured for TA = 25°C, V+ = 5 V, V− = 0 V, VCM = V+/2, and RL > 10 MΩ to V+/2.(1) PARAMETER ROUT MIN (2) TEST CONDITIONS Open-loop output impedance f = 3 MHz THD+N Total harmonic distortion + noise f = 1 kHz , AV = 1 RL = 10 kΩ CIN Input capacitance TYP (3) MAX (2) 70 UNIT Ω 0.003% 6 pF 6.7 Electrical Characteristics – ±5-V Unless otherwise specified, all limits are ensured for TA = 25°C, V+ = 5 V, V− = –5 V, VCM = 0 V, and RL > 10 MΩ to VCM. (1) PARAMETER VOS Input offset voltage TCVOS Input offset voltage drift Input bias current IB TEST CONDITIONS MIN (2) TYP (3) MAX (2) –500 ±50 500 at the temperature extremes –800 at the temperature extremes –5 (4) 0.25 (4) (5) 0.3 Input offset current 40 86 –5 V ≤ VCM ≤ 5 V Common-mode rejection ratio LMV842 and LMV844 –5 V ≤ VCM ≤ 5 V at the temperature extremes 80 PSRR Power supply rejection ratio 2.7 V ≤ V+ ≤ 12 V, VO = 0V at the temperature extremes 86 CMVR Input common-mode voltage range CMRR Large signal voltage gain RL = 10 kΩ VO = −4.8 V to 4.8 V RL = 2 kΩ to 0 V Output swing high, (measured from V+) RL = 10 kΩ to 0 V VO RL = 2 kΩ to 0 V Output swing low, (measured from V−) RL = 10 kΩ to 0 V (3) (4) (5) at the temperature extremes 108 at the temperature extremes dB 5.2 126 136 dB 96 95 at the temperature extremes 44 75 95 105 at the temperature extremes 160 200 52 at the temperature extremes 130 155 at the temperature extremes V dB 96 100 pA dB 82 100 at the temperature extremes µV/°C dB 106 –5.2 µV fA 112 80 86 CMRR ≥ 50 dB RL = 2 kΩ VO = −4.7 V to 4.7 V AVOL 10 300 Common-mode rejection ratio LMV841 (2) 5 at the temperature extremes IOS (1) 800 UNIT 80 100 mV mV mV mV 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. Limits are 100% production tested at 25°C. Limits over the operating temperature range are ensured through correlations using statistical quality control (SQC) method. Typical values represent the most likely parametric norm as determined at the time of characterization. Actual typical values may vary over time and will also depend on the application and configuration. The typical values are not tested and are not ensured on shipped production material. This parameter is ensured by design and/or characterization and is not tested in production. Positive current corresponds to current flowing into the device. Copyright © 2006–2016, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 7 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 www.ti.com Electrical Characteristics – ±5-V (continued) Unless otherwise specified, all limits are ensured for TA = 25°C, V+ = 5 V, V− = –5 V, VCM = 0 V, and RL > 10 MΩ to VCM.(1) PARAMETER TEST CONDITIONS Sourcing VO = 0 V VIN = 100 mV IO Output short-circuit current (6) (7) Sinking VO = 0 V VIN = −100 mV TYP (3) 20 37 20 at the temperature extremes 1.03 SR Slew rate GBW Φm en Input-referred voltage noise f = 1 kHz 20 ROUT Open-loop output impedance f = 3 MHz 70 THD+N Total harmonic distortion + noise f = 1 kHz , AV = 1 RL = 10kΩ CIN Input capacitance (7) (8) 8 mA 15 at the temperature extremes 1.7 2 AV = +1, VO = 9 VPP 10% to 90% UNIT mA 29 Supply current (8) MAX (2) 15 IS (6) Per Channel at the temperature extremes MIN (2) mA 2.5 V/µs Gain bandwidth product 4.5 MHz Phase margin 67 Deg nV/ Ω 0.006% 3 pF 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 onto a PCB. Short circuit test is a momentary test. Number specified is the slower of positive and negative slew rates. Submit Documentation Feedback Copyright © 2006–2016, Texas Instruments Incorporated Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 www.ti.com SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 6.8 Typical Characteristics At TA = 25°C, RL = 10 kΩ, VS = 5 V. Unless otherwise specified. 200 200 VS = 3.3V 150 125°C 100 85°C 50 VOS (PV) VOS (PV) 100 VS = 5.0V 150 0 -50 -100 50 125°C 0 85°C -50 25°C -100 25°C -150 -150 -40°C -200 -1 0 1 2 3 -200 -1 4 -40°C 0 1 2 VCM (V) 3 4 5 6 VCM (V) Figure 1. VOS vs VCM Over Temperature at 3.3 V Figure 2. VOS vs VCM Over Temperature at 5 V 200 200 VS = ±5V 150 150 125°C 100 0 VOS (PV) 85°C 50 VOS (PV) 100 25°C 125°C 50 0 85°C -50 -50 25°C -100 -40°C -100 -150 -150 -200 -6 -200 2 -40°C -4 -2 0 2 4 6 4 6 8 10 12 14 VCM (V) VSUPPLY (V) Figure 3. VOS vs VCM Over Temperature at ±5 V Figure 4. VOS vs Supply Voltage 140 200 RL = 10 k: OPEN LOOP GAIN (dB) 150 VOS (PV) 100 50 0 3.3V -50 ±5V -100 5V 130 RL = 2 k: 120 110 RL = 600Ö 100 -150 -200 -50 -25 0 25 50 75 100 125 TEMPERATURE (°C) Figure 5. VOS vs Temperature Copyright © 2006–2016, Texas Instruments Incorporated 90 0 100 200 300 400 500 OUTPUT SWING FROM RAIL (mV) Figure 6. DC Gain vs VOUT Submit Documentation Feedback Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 9 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 www.ti.com Typical Characteristics (continued) At TA = 25°C, RL = 10 kΩ, VS = 5 V. Unless otherwise specified. 20 TA = 25°C 0.15 15 0.10 10 0.05 5 IBIAS (pA) IBIAS (pA) 0.20 0 -0.05 TA = 85°C 0 5.0V -5 5V -0.10 -10 ±5V -0.15 -0.20 -5 -4 -3 -2 -1 0 1 ±5V -15 3.3V 2 3 4 -20 -5 5 3.3V -4 -3 -2 -1 VCM (V) 1 2 3 4 5 VCM (V) Figure 7. Input Bias Current vs VCM Figure 8. Input Bias Current vs VCM 200 1.4 TA = 125°C 125°C 150 SUPPLY CURRENT (mA) 1.3 100 IBIAS (pA) 0 50 0 5.0V -50 -100 ±5V 85°C 1.1 25°C 1.0 0.9 3.3V -150 1.2 -40°C -200 -5 -4 -3 -2 -1 0 1 2 3 4 0.8 2 5 4 6 VCM (V) 8 10 12 14 SUPPLY VOLTAGE (V) Figure 9. Input Bias Current vs VCM Figure 10. Supply Current Per Channel vs Supply Voltage 40 45 125°C 85°C -40°C 40 25°C ISOURCE (mA) ISINK (mA) 35 30 25 20 2 4 6 85°C 125°C 8 10 12 Figure 11. Sinking Current vs Supply Voltage Submit Documentation Feedback 25°C -40°C 30 SUPPLY VOLTAGE (V) 10 35 25 2 4 6 8 10 12 SUPPLY VOLTAGE (V) Figure 12. Sourcing Current vs Supply Voltage Copyright © 2006–2016, Texas Instruments Incorporated Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 www.ti.com SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 Typical Characteristics (continued) At TA = 25°C, RL = 10 kΩ, VS = 5 V. Unless otherwise specified. 135 65 RL = 2 k: 60 125°C VOUT FROM RAIL HIGH (mV) 115 85°C 105 95 85 75 25°C 65 55 -40°C RL = 10 k: 55 125°C 50 85°C 45 40 35 25°C 30 -40°C 25 20 45 35 2 4 6 8 10 12 15 2 14 4 Figure 13. Output Swing High vs Supply Voltage RL = 2 kΩ VOUT FROM RAIL LOW (mV) VOUT FROM RAIL LOW (mV) 70 125°C 130 85°C 120 110 100 90 25°C 80 70 -40°C 60 14 4 6 SINK 8 125°C 125°C 65 60 85°C 55 50 45 25°C 40 -40°C 35 10 12 25 2 14 4 6 8 10 12 14 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) 0.4 RL = 10 k: 30 Figure 15. Output Swing Low vs Supply Voltage RL = 2 kΩ Figure 16. Output Swing Low vs Supply Voltage RL = 10 kΩ 60 85°C 130 GAIN PHASE -40°C 0.3 0.2 90 40 -40°C 25°C 0.1 VS = 3.3V, 5.0V, +/-5V 0 -0.1 25°C GAIN (dB) VOUT FROM RAIL (V) 12 75 140 0.5 10 Figure 14. Output Swing High vs Supply Voltage RL = 10 kΩ RL = 2 k: 50 2 8 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) 150 6 125°C -40°C 20 -40°C -0.2 10 0 -0.3 125°C 85°C -0.4 125°C CL = 20 pF -20 10k 100k SOURCE -0.5 0 5 10 50 PHASE (°) VOUT FROM RAIL HIGH (mV) 125 15 20 ILOAD (mA) 25 30 Figure 17. Output Voltage Swing vs Load Current Copyright © 2006–2016, Texas Instruments Incorporated 1M -30 10M FREQUENCY (Hz) Figure 18. Open-Loop Frequency Response Over Temperature Submit Documentation Feedback Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 11 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 www.ti.com Typical Characteristics (continued) At TA = 25°C, RL = 10 kΩ, VS = 5 V. Unless otherwise specified. 60 130 GAIN 80 PHASE 70 VS=10V CL=20 pF 90 40 3.3V 60 50 0 50 PHASE(°) 20 PHASE (°) GAIN (dB) 5.0V VS = 3.3V CL = 100 pF 40 30 ±5V 20 10 10 VS = 3.3V, 5.0V, 10V CL = 20 pF, 50 pF, 100 pF -20 10k 100k 1M 0 1 -30 10M 10 100 1000 CLOAD (pF) FREQUENCY (Hz) Figure 20. Phase Margin vs CL Figure 19. Open-Loop Frequency Response Over Load Conditions 120 3.3V 110 5.0V 100 3.3V ±5V PSRR (dB) +PSRR 3.3V 5.0V ±5V 60 40 20 3.3V: VCM = 1V CMRR (dB) 5.0V 80 90 ±5V 70 50 5.0V: VCM = 2.5V -PSRR ±5V : VCM = 0V ±5V: VCM = 0V 0 100 3.3V : VCM = 1V 5.0V : VCM = 2.5V 30 1k 10k 100k 1M 100 FREQUENCY (Hz) 1k 10k 100k 1M FREQUENCY (Hz) Figure 21. PSRR vs Frequency Figure 22. CMRR vs Frequency 160 140 500 mV/DIV CHANNEL SEPARATION (dB) 180 120 100 f = 250 kHz AV = +1 VIN = 2 VPP CL = 20 pF 80 VS = 3.3V, 5.0V, ±5V 60 100 1k 10k 100k 1M 400 ns/DIV FREQUENCY (Hz) Figure 23. Channel Separation vs Frequency 12 Submit Documentation Feedback Figure 24. Large Signal Step Response With Gain = 1 Copyright © 2006–2016, Texas Instruments Incorporated Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 www.ti.com SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 Typical Characteristics (continued) 50 mV/DIV 200 mV/DIV At TA = 25°C, RL = 10 kΩ, VS = 5 V. Unless otherwise specified. f = 250 kHz AV = +1 f = 250 kHz AV = +10 VIN = 100 mVPP CL = 20 pF VIN = 200 mVPP CL = 20 pF 400 ns/DIV 400 ns/DIV Figure 25. Large Signal Step Response With Gain = 10 Figure 26. Small Signal Step Response With Gain = 1 20 mV/DIV SLEW RATE (V/µs) 3.0 f = 250 kHz AV = +10 VIN = 10 mVPP CL = 20 pF FALLING EDGE 2.5 2.0 RISING EDGE AV = +1 1.5 VIN = 2 VPP RL = 10 kΩ CL = 20 pF 1.0 400 ns/DIV 2 4 6 8 10 SUPPLY VOLTAGE (V) 12 Figure 28. Slew Rate vs Supply Voltage Figure 27. Small Signal Step Response With Gain = 10 100 50 f = 250 kHz AV = +1 VIN = 200 mVPP 50 NOISE (nV/Hz) OVERSHOOT (%) 40 30 ±5V 20 5.0V 3.3V 5.0V 20 10 3.3V ±5V 10 0 10 100 CLOAD (pF) Figure 29. Overshoot vs CL Copyright © 2006–2016, Texas Instruments Incorporated 1000 10 100 1k 10k 100k FREQUENCY (Hz) Figure 30. Input Voltage Noise vs Frequency Submit Documentation Feedback Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 13 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 www.ti.com Typical Characteristics (continued) At TA = 25°C, RL = 10 kΩ, VS = 5 V. Unless otherwise specified. 1 10 VS = 5V RL = 10 kΩ AV = +10 0.1 1 VOUT = 4.5 VPP AV = +10 THD + N (%) THD + N (%) CL = 50 pF 0.01 0.1 0.01 AV = +1 VS = 5V RL = 10 kΩ CL = 20 pF f = 1 kHz AV = +1 0.001 10 100 1k 10k 0.001 0.001 100k 0.01 FREQUENCY (Hz) 0.1 1 10 VOUT (V) Figure 31. THD+N vs Frequency Figure 32. THD+N vs VOUT 100 10 ROUT (:) 100x 1 10x 0.1 1x 0.01 0.001 100 1k 10k 100k 1M 10M FREQUENCY (Hz) Figure 33. Closed-Loop Output Impedance vs Frequency 14 Submit Documentation Feedback Copyright © 2006–2016, Texas Instruments Incorporated Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 www.ti.com SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 7 Detailed Description 7.1 Overview The LMV84x devices are operational amplifiers with near-precision specifications: low noise, low temperature drift, low offset, and rail-to-rail input and output. Possible application areas include instrumentation, medical, test equipment, audio, and automotive applications. Its low supply current of 1 mA per amplifier, temperature range of −40°C to 125°C, 12-V supply with CMOS input, and the small SC70 package for the LMV841 make the LMV84x a unique op amp family and a perfect choice for portable electronics. 7.2 Functional Block Diagram 7.3 Feature Description 7.3.1 Input Protection The LMV84x have a set of anti-parallel diodes D1 and D2 between the input pins, as shown in Figure 34. These diodes are present to protect the input stage of the amplifier. At the same time, they limit the amount of differential input voltage that is allowed on the input pins. A differential signal larger than one diode voltage drop can damage the diodes. The differential signal between the inputs needs to be limited to ±300 mV or the input current needs to be limited to ±10 mA. NOTE When the op amp is slewing, a differential input voltage exists that forward-biases the protection diodes. This may result in current being drawn from the signal source. While this current is already limited by the internal resistors R1 and R2 (both 130 Ω), a resistor of 1 kΩ can be placed in the feedback path, or a 500-Ω resistor can be placed in series with the input signal for further limitation. Copyright © 2006–2016, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 15 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 www.ti.com Feature Description (continued) V + + V ESD IN IN + ESD V R1 D1 D2 + V ESD + - VOUT R2 ESD - V - V Figure 34. Protection Diodes Between the Input Pins 7.3.2 Input Stage The input stage of this amplifier consists of both a PMOS and an NMOS input pair to achieve a rail-to-rail input range. For input voltages close to the negative rail, only the PMOS pair is active. Close to the positive rail, only the NMOS pair is active. In a transition region that extends from approximately 2 V below V+ to 1 V below V+, both pairs are active, and one pair gradually takes over from the other. In this transition region, the input-referred offset voltage changes from the offset voltage associated with the PMOS pair to that of the NMOS pair. The input pairs are trimmed independently to ensure an input offset voltage of less then 0.5 mV at room temperature over the complete rail-to-rail input range. This also significantly improves the CMRR of the amplifier in the transition region. NOTE The CMRR and PSRR limits in the tables are large-signal numbers that express the maximum variation of the input offset of the amplifier over the full common-mode voltage and supply voltage range, respectively. When the common-mode input voltage of the amplifier is within the transition region, the small signal CMRR and PSRR may be slightly lower than the large signal limits. 7.4 Device Functional Modes 7.4.1 Driving Capacitive Load The LMV84x can be connected as noninverting unity gain amplifiers. This configuration is the most sensitive to capacitive loading. The combination of a capacitive load placed on the output of an amplifier along with the output impedance of the amplifier creates a phase lag, which reduces the phase margin of the amplifier. If the phase margin is significantly reduced, the response is under-damped, which causes peaking in the transfer. When there is too much peaking, the op amp might start oscillating. The LMV84x can directly drive capacitive loads up to 100 pF without any stability issues. To drive heavier capacitive loads, an isolation resistor (RISO) must be used, as shown in Figure 35. By using this isolation resistor, the capacitive load is isolated from the output of the amplifier, and hence, the pole caused by CL is no longer in the feedback loop. The larger the value of RISO, the more stable the output voltage is. If values of RISO are sufficiently large, the feedback loop is stable, independent of the value of CL. However, larger values of RISO result in reduced output swing and reduced output current drive. 16 Submit Documentation Feedback Copyright © 2006–2016, Texas Instruments Incorporated Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 www.ti.com SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 Device Functional Modes (continued) RISO - V OUT V IN + CL Figure 35. Isolating Capacitive Load 7.4.2 Noise Performance The LMV84x devices have good noise specifications, and are frequently used in low-noise applications. Therefore it is important to determine the noise of the total circuit. Besides the input-referred noise of the op amp, the feedback resistors may have an important contribution to the total noise. For applications with a voltage input configuration, in general it is beneficial general, beneficial to keep the resistor values low. In these configurations high resistor values mean high noise levels. However, using low resistor values will increase the power consumption of the application. This is not always acceptable for portable applications, so there is a trade-off between noise level and power consumption. Besides the noise contribution of the signal source, three types of noise need to be taken into account for calculating the noise performance of an op amp circuit: • Input-referred voltage noise of the op amp • Input-referred current noise of the op amp • Noise sources of the resistors in the feedback network, configuring the op amp To calculate the noise voltage at the output of the op amp, the first step is to determine a total equivalent noise source. This requires the transformation of all noise sources to the same reference node. A convenient choice for this node is the input of the op amp circuit. The next step is to add all the noise sources. The final step is to multiply the total equivalent input voltage noise with the gain of the op amp configuration. If the input-referred voltage noise of the op amp is already placed at the input, the user can use the inputreferred voltage noise without further transferring. The input-referred current noise needs to be converted to an input-referred voltage noise. The current noise is negligibly small, as long as the equivalent resistance is not unrealistically large, so the user can leave the current noise out for these examples. That leaves the user with the noise sources of the resistors, being the thermal noise voltage. The influence of the resistors on the total noise can be seen in the following examples, one with high resistor values and one with low resistor values. Both examples describe an op amp configuration with a gain of 101 which gives the circuit a bandwidth of 44.5 kHz. The op amp noise is the same for both cases, that is, an input-referred noise voltage of 20nV/ and a negligibly small input-referred noise current. + en in RF RG Figure 36. Noise Circuit Copyright © 2006–2016, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 17 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 www.ti.com Device Functional Modes (continued) To calculate the noise of the resistors in the feedback network, the equivalent input-referred noise resistance is needed. For the example in Figure 36, this equivalent resistance Req can be calculated using Equation 1: R ´ RG Req = F RF + RG (1) The voltage noise of the equivalent resistance can be calculated using Equation 2: enr = 4kTReq where • • • • • enr = thermal noise voltage of the equivalent resistor Req (V/ ) k = Boltzmann constant (1.38 x 10–23 J/K) T = absolute temperature (K) Req = resistance (Ω) (2) The total equivalent input voltage noise is given by Equation 3: en in = env 2 + enr 2 where • • en in = total input equivalent voltage noise of the circuit env = input voltage noise of the op amp (3) The final step is multiplying the total input voltage noise by the noise gain using Equation 4, which is in this case the gain of the op amp configuration: en out = en in ´ Anoise (4) The equivalent resistance for the first example with a resistor RF of 10 MΩ and a resistor RG of 100 kΩ at 25°C (298 K) equals Equation 5: R ´ RG 10 M W ´ 100 k W Req = F = = 99 k W RF + RG 10 M W + 100 k W (5) Now the noise of the resistors can be calculated using Equation 6, yielding: enr = 4kTReq = 4 ´ 1.38 ´ 10-23 J/K ´ 298K ´ 99 k W = 40 nV/ Hz (6) The total noise at the input of the op amp is calculated in Equation 7: en in = env 2 + enr 2 = (20 nV/ Hz )2 + (40 nV/ Hz )2 = 45 nV/ Hz (7) For the first example, this input noise, multiplied with the noise gain, in Equation 8 gives a total output noise of: en out = en in ´ Anoise = 45 nV/ Hz ´ 101 = 4.5 mV/ Hz (8) In the second example, with a resistor RF of 10 kΩ and a resistor RG of 100 Ω at 25°C (298 K), the equivalent resistance equals Equation 9: R ´ RG 10 k W ´ 100 W Req = F = = 99 W RF + RG 10 k W + 100 W (9) The resistor noise for the second example is calculated in Equation 10: 18 Submit Documentation Feedback Copyright © 2006–2016, Texas Instruments Incorporated Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 www.ti.com SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 Device Functional Modes (continued) enr = 4kTReq = 4 ´ 1.38 ´ 10-23 J/K ´ 298 K ´ 99 W = 1 nV/ Hz (10) The total noise at the input of the op amp is calculated in Equation 10: en in = env 2 + enr 2 = (20 nV/ Hz )2 + (1 nV/ Hz )2 = 20 nV/ Hz (11) For the second example the input noise, multiplied with the noise gain, in Equation 12 gives an output noise of: en out = en in ´ Anoise = 20 nV/ Hz ´ 101 = 2 mV/ Hz (12) In the first example the noise is dominated by the resistor noise due to the very high resistor values, in the second example the very low resistor values add only a negligible contribution to the noise and now the dominating factor is the op amp itself. When selecting the resistor values, it is important to choose values that do not add extra noise to the application. Choosing values above 100 kΩ may increase the noise too much. Low values keep the noise within acceptable levels; choosing very low values however, does not make the noise even lower, but can increase the current of the circuit. 7.4.3 Interfacing to High Impedance Sensor With CMOS inputs, the LMV84x are particularly suited to be used as high impedance sensor interfaces. Many sensors have high source impedances that may range up to 10 MΩ. The input bias current of an amplifier loads the output of the sensor, and thus cause a voltage drop across the source resistance, as shown in Figure 37. When an op amp is selected with a relatively high input bias current, this error may be unacceptable. The low input current of the LMV84x significantly reduces such errors. The following examples show the difference between a standard op amp input and the CMOS input of the LMV84x. The voltage at the input of the op amp can be calculated with Equation 13: VIN+ = VS – IB × RS (13) For a standard op amp, the input bias Ib can be 10 nA. When the sensor generates a signal of 1 V (VS) and the sensors impedance is 10 MΩ (RS), the signal at the op amp input is calculated in Equation 14: VIN = 1 V - 10 nA × 10 MΩ = 1 V - 0.1 V = 0.9 V (14) For the CMOS input of the LMV84x, which has an input bias current of only 0.3 pA, this would give Equation 15: VIN = 1 V – 0.3 pA × 10 MΩ = 1 V – 3 µV = 0.999997 V (15) The conclusion is that a standard op amp, with its high input bias current input, is not a good choice for use in impedance sensor applications. The LMV84x, in contrast, are much more suitable due to the low input bias current. The error is negligibly small; therefore, the LMV84x are a must for use with high impedance sensors. SENSOR RS VS + - IB V VIN+ + + - V Figure 37. High Impedance Sensor Interface Copyright © 2006–2016, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 19 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 www.ti.com 8 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality. 8.1 Application Information The rail-to-rail input and output of the LMV84x and the wide supply voltage range make these amplifiers ideal to use in numerous applications. Three sample applications, namely the active filter circuit, high-side current sensing, and thermocouple sensor interface, are provided in the Typical Applications section. 8.2 Typical Applications 8.2.1 Active Filter Circuit C C R2 R2 R1 C R3 R1 C + R3 + Figure 38. Active Band-Pass Filter Implementation 8.2.1.1 Design Requirements In this example it is required to design a bandpass filter with band-pass frequency of 10 kHz, and a center frequence of approximately 10% from the total frequence of the filter. This is achieved by cascading two bandpass filters, A and B, with slightly different center frequencies. 8.2.1.2 Detailed Design Procedure The center frequency of the separate band-pass filters A, and B can be calculated by Equation 16: fmid = R1 + R3 1 2pC R1R2R3 where • • • • C = 33 nF R1 = 2 KΩ R2 = 6.2 KΩ and R3 = 45 Ω (16) This gives Equation 17 for filter A: fmid = 1 p ´ 33 nF 2 k W + 6.2 k W = 9.2 kHz 2 k W ´ 6.2 k W ´ 45 k W (17) and Equation 18 for filter B with C = 27nF: fmid = 1 p ´ 27 nF 2 k W + 6.2 k W = 11.2 kHz 2 k W ´ 6.2 k W ´ 45 k W (18) Bandwidth can be calculated by Equation 19: 20 Submit Documentation Feedback Copyright © 2006–2016, Texas Instruments Incorporated Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 www.ti.com SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 Typical Applications (continued) B= 1 pR2C (19) For filter A, this gives Equation 20: 1 = 1.6 kHz B= p ´ 6.2 k W ´ 33 nF (20) and Equation 21 for filter B: 1 = 1.9 kHz B= p ´ 6.2 k W ´ 27 nF (21) 8.2.1.3 Application Curve The responses of filter A and filter B are shown as the thin lines in Figure 39; the response of the combined filter is shown as the thick line. Shifting the center frequencies of the separate filters farther apart, results in a wider band; however, positioning the center frequencies too far apart results in a less flat gain within the band. For wider bands more band-pass filters can be cascaded. 10 FILTER A FILTER B GAIN (dB) 0 -10 -20 -30 COMBINED FILTER -40 1k 10k 100k FREQUENCY (Hz) Figure 39. Active Band-Pass Filter Curve NOTE Use the WEBENCH internet tools at www.ti.com for your filter application. 8.2.2 High-Side, Current-Sensing Circuit V RF + RG RS + RG RF LOAD Z Figure 40. High-Side, Current-Sensing Circuit Copyright © 2006–2016, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 21 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 www.ti.com Typical Applications (continued) 8.2.2.1 Design Requirements In this example, it is desired to measure a current between 0 A and 2 A using a sense resistor of 100 mΩ, and convert it to an output voltage of 0 to 5 V. A current of 2 A flowing through the load and the sense resistor results in a voltage of 200 mV across the sense resistor. The op amp amplifies this 200 mV to fit the current range to the output voltage range. 8.2.2.2 Detailed Design Procedure To measure current at a point in a circuit, a sense resistor is placed in series with the load, as shown in Figure 40. The current flowing through this sense resistor results in a voltage drop, that is amplified by the op amp. The rail-to-rail input and the low VOS features make the LMV84x ideal op amps for high-side, currentsensing applications. The input and the output relation of the circuit is given by Equation 22: VOUT = RF/RG × VSENSE (22) For a load current of 2 A and an output voltage of 5 V the gain would be VOUT / VSENSE = 25. If the feedback resistor, RF, is 100 kΩ, then the value for RG is 4 kΩ. The tolerance of the resistors has to be low to obtain a good common-mode rejection. 8.2.3 Thermocouple Sensor Signal Amplification Figure 41 is a typical example for a thermocouple amplifier application using an LMV841, LMV842, or LMV844. A thermocouple senses a temperature and converts it into a voltage. This signal is then amplified by the LMV841, LMV842, or LMV844. An ADC can then convert the amplified signal to a digital signal. For further processing the digital signal can be processed by a microprocessor, and can be used to display or log the temperature, or the temperature data can be used in a fabrication process. Cold junction Temperature LM35 RF RG T Metal A Copper - RG LMV841 + Metal B Thermocouple Copper Amplified Thermocouple Output RF Cold junction Reference Figure 41. Thermocouple Sensor Interface 8.2.3.1 Design Requirements In this example it is desired to measure temperature in the range of 0°C to 500°C with a resolution of 0.5°C using a K-type thermocouple sensor. The power supply for both the LMV841, LMV842, or LMV844 and the ADC is 3.3 V. 8.2.3.2 Detailed Design Procedure A thermocouple is a junction of two different metals. These metals produce a small voltage that increases with temperature. A K-type thermocouple is a very common temperature sensor made of a junction between NickelChromium and Nickel-Aluminum. There are several reasons for using the K-type thermocouple. These include temperature range, the linearity, the sensitivity, and the cost. 22 Submit Documentation Feedback Copyright © 2006–2016, Texas Instruments Incorporated Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 www.ti.com SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 Typical Applications (continued) A K-type thermocouple has a wide temperature range. The range of this thermocouple is from approximately −200°C to approximately 1200°C, as can be seen in Figure 42. This covers the generally used temperature ranges. Over the main part of the range the behavior is linear. This is important for converting the analog signal to a digital signal. The K-type thermocouple has good sensitivity when compared to many other types; the sensitivity is 41 µV/°C. Lower sensitivity requires more gain and makes the application more sensitive to noise. In addition, a K-type thermocouple is not expensive, many other thermocouples consist of more expensive materials or are more difficult to produce. THERMOCOUPLE VOLTAGE (mV) 50 40 30 20 10 0 -10 -200 0 200 400 600 800 1000 1200 TEMPERATURE (°C) Figure 42. K-Type Thermocouple Response The temperature range of 0°C to 500°C results in a voltage range from 0 mV to 20.6 mV produced by the thermocouple. This is shown in Figure 42. To obtain the best accuracy the full ADC range of 0 to 3.3 V is used and the gain needed for this full range can be calculated Equation 23: AV = 3.3 V / 0.0206 V = 160 (23) If RG is 2 kΩ, then the value for RF can be calculated with this gain of 160. Because AV = RF / RG, RF can be calculated in Equation 24: RF = AV × RG = 160 × 2 kΩ = 320 kΩ (24) To achieve a resolution of 0.5°C a step smaller than the minimum resolution is needed. This means that at least 1000 steps are necessary (500°C/0.5°C). A 10-bit ADC would be sufficient as this gives 1024 steps. A 10-bit ADC such as the two channel 10-bit ADC102S021 would be a good choice. At the point where the thermocouple wires are connected to the circuit on the PCB unwanted parasitic thermocouple is formed, introducing error in the measurements of the actual thermocouple sensor. Using an isothermal block as a reference will compensate for this additional thermocouple effect. An isothermal block is a good heat conductor. This means that the two thermocouple connections both have the same temperature. The temperature of the isothermal block can be measured, and thereby the temperature of the thermocouple connections. This is usually called the cold junction reference temperature. In the example, an LM35 is used to measure this temperature. This semiconductor temperature sensor can accurately measure temperatures from −55°C to 150°C. The ADC in this example also coverts the signal from the LM35 to a digital signal, hence, the microprocessor can compensate for the amplified thermocouple signal of the unwanted thermocouple junction at the connector. Copyright © 2006–2016, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 23 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 www.ti.com 9 Power Supply Recommendations The LMV84x is specified for operation from 2.7 V to 12 V (±1.35 V to ±6 V) over a –40°C to 125°C temperature range. Parameters that can exhibit significant variance with regard to operating voltage or temperature are presented in the Absolute Maximum Ratings. CAUTION Supply voltages larger than 13.2 V can permanently damage the device. For proper operation, the power supplies must be properly decoupled. For decoupling the supply lines, TI suggests placing 10-nF capacitors as close as possible to the operational amplifier power supply pins. For single supply, place a capacitor between V+ and V– supply leads. For dual supplies, place one capacitor between V+ and ground, and one capacitor between V– and ground. 10 Layout 10.1 Layout Guidelines • • • • • The V+ pin must be bypassed to ground with a low-ESR capacitor. The optimum placement is closest to the V+ and ground pins. Take care to minimize the loop area formed by the bypass capacitor connection between V+ and ground. The ground pin must be connected to the PCB ground plane at the pin of the device. The feedback components must be placed as close to the device as possible to minimize strays. 10.2 Layout Example Place components close to device and to each other to reduce parasitic error VOUTA Place low-ESR ceramic bypass capacitor close to device RF Run the input traces as far away from the supply lines as possible OUTA V+ GND -INA OUTB VIN +INA -INB V- +INB GND RG Place low-ESR ceramic bypass capacitor close to device GND VS- Figure 43. Layout Example (Top View) 24 Submit Documentation Feedback Copyright © 2006–2016, Texas Instruments Incorporated Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 LMV841, LMV842, LMV844 LMV841-Q1, LMV842-Q1, LMV844-Q1 www.ti.com SNOSAT1H – OCTOBER 2006 – REVISED JULY 2016 11 Device and Documentation Support 11.1 Related Links The table below lists quick access links. Categories include technical documents, support and community resources, tools and software, and quick access to sample or buy. Table 1. Related Links PARTS PRODUCT FOLDER SAMPLE & BUY TECHNICAL DOCUMENTS TOOLS & SOFTWARE SUPPORT & COMMUNITY LMV841 Click here Click here Click here Click here Click here LMV842 Click here Click here Click here Click here Click here LMV844 Click here Click here Click here Click here Click here LMV841-Q1 Click here Click here Click here Click here Click here LMV842-Q1 Click here Click here Click here Click here Click here LMV844-Q1 Click here Click here Click here Click here Click here 11.2 Receiving Notification of Documentation Updates To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper right corner, click on Alert me to register and receive a weekly digest of any product information that has changed. For change details, review the revision history included in any revised document. 11.3 Community Resources The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help solve problems with fellow engineers. Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and contact information for technical support. 11.4 Trademarks E2E is a trademark of Texas Instruments. All other trademarks are the property of their respective owners. 11.5 Electrostatic Discharge Caution 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. 11.6 Glossary SLYZ022 — TI Glossary. This glossary lists and explains terms, acronyms, and definitions. 12 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation. Copyright © 2006–2016, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMV841 LMV842 LMV844 LMV841-Q1 LMV842-Q1 LMV844-Q1 25 PACKAGE OPTION ADDENDUM www.ti.com 4-Mar-2016 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) LMV841MG/NOPB ACTIVE SC70 DCK 5 1000 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 A97 LMV841MGX/NOPB ACTIVE SC70 DCK 5 3000 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 A97 LMV841QMG/NOPB ACTIVE SC70 DCK 5 1000 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 ATA LMV841QMGX/NOPB ACTIVE SC70 DCK 5 3000 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 ATA LMV842MA/NOPB ACTIVE SOIC D 8 95 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM LMV84 2MA LMV842MAX/NOPB ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM LMV84 2MA LMV842MM/NOPB ACTIVE VSSOP DGK 8 1000 Green (RoHS CU NIPDAUAG | CU SN Level-1-260C-UNLIM & no Sb/Br) -40 to 125 AC4A LMV842MMX/NOPB ACTIVE VSSOP DGK 8 3500 Green (RoHS CU NIPDAUAG | CU SN Level-1-260C-UNLIM & no Sb/Br) -40 to 125 AC4A LMV842QMA/NOPB ACTIVE SOIC D 8 95 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LMV84 2QMA LMV842QMAX/NOPB ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LMV84 2QMA LMV842QMM/NOPB ACTIVE VSSOP DGK 8 1000 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 AA7A LMV842QMMX/NOPB ACTIVE VSSOP DGK 8 3500 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 AA7A LMV844MA/NOPB ACTIVE SOIC D 14 55 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LMV844MA LMV844MAX/NOPB ACTIVE SOIC D 14 2500 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LMV844MA LMV844MT/NOPB ACTIVE TSSOP PW 14 94 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LMV844 MT LMV844MTX/NOPB ACTIVE TSSOP PW 14 2500 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LMV844 MT LMV844QMA/NOPB ACTIVE SOIC D 14 55 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 125 LMV844 QMA Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com Orderable Device 4-Mar-2016 Status (1) LMV844QMAX/NOPB ACTIVE Package Type Package Pins Package Drawing Qty SOIC D 14 2500 Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM Op Temp (°C) Device Marking (4/5) -40 to 125 LMV844 QMA (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. 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OTHER QUALIFIED VERSIONS OF LMV841, LMV841-Q1, LMV842, LMV842-Q1, LMV844, LMV844-Q1 : Addendum-Page 2 Samples PACKAGE OPTION ADDENDUM www.ti.com 4-Mar-2016 • Catalog: LMV841, LMV842, LMV844 • Automotive: LMV841-Q1, LMV842-Q1, LMV844-Q1 NOTE: Qualified Version Definitions: • Catalog - TI's standard catalog product • Automotive - Q100 devices qualified for high-reliability automotive applications targeting zero defects Addendum-Page 3 PACKAGE MATERIALS INFORMATION www.ti.com 18-May-2016 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 LMV841MG/NOPB SC70 DCK 5 1000 178.0 8.4 2.25 2.45 1.2 4.0 8.0 Q3 LMV841MGX/NOPB SC70 DCK 5 3000 178.0 8.4 2.25 2.45 1.2 4.0 8.0 Q3 LMV841QMG/NOPB SC70 DCK 5 1000 178.0 8.4 2.25 2.45 1.2 4.0 8.0 Q3 LMV841QMGX/NOPB SC70 DCK 5 3000 178.0 8.4 2.25 2.45 1.2 4.0 8.0 Q3 LMV842MAX/NOPB SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LMV842MM/NOPB VSSOP DGK 8 1000 178.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 LMV842MMX/NOPB VSSOP DGK 8 3500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 LMV842MMX/NOPB VSSOP DGK 8 3500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 LMV842QMAX/NOPB SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LMV842QMM/NOPB VSSOP DGK 8 1000 178.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 LMV842QMMX/NOPB VSSOP DGK 8 3500 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 LMV844MAX/NOPB SOIC D 14 2500 330.0 16.4 6.5 9.35 2.3 8.0 16.0 Q1 LMV844MTX/NOPB TSSOP PW 14 2500 330.0 12.4 6.95 5.6 1.6 8.0 12.0 Q1 LMV844QMAX/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 18-May-2016 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LMV841MG/NOPB SC70 DCK 5 1000 210.0 185.0 35.0 LMV841MGX/NOPB SC70 DCK 5 3000 210.0 185.0 35.0 LMV841QMG/NOPB SC70 DCK 5 1000 210.0 185.0 35.0 LMV841QMGX/NOPB SC70 DCK 5 3000 210.0 185.0 35.0 LMV842MAX/NOPB SOIC D 8 2500 367.0 367.0 35.0 LMV842MM/NOPB VSSOP DGK 8 1000 210.0 185.0 35.0 LMV842MMX/NOPB VSSOP DGK 8 3500 364.0 364.0 27.0 LMV842MMX/NOPB VSSOP DGK 8 3500 367.0 367.0 35.0 LMV842QMAX/NOPB SOIC D 8 2500 367.0 367.0 35.0 LMV842QMM/NOPB VSSOP DGK 8 1000 210.0 185.0 35.0 LMV842QMMX/NOPB VSSOP DGK 8 3500 367.0 367.0 35.0 LMV844MAX/NOPB SOIC D 14 2500 367.0 367.0 35.0 LMV844MTX/NOPB TSSOP PW 14 2500 367.0 367.0 35.0 LMV844QMAX/NOPB SOIC D 14 2500 367.0 367.0 35.0 Pack Materials-Page 2 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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