LMP8640 LMP8640HV www.ti.com SNOSB28F - AUGUST 2010 - REVISED APRIL 2013 Precision High Voltage Current Sense Amplifier Check for Samples: LMP8640, LMP8640HV FEATURES DESCRIPTION * * The LMP8640 and the LMP8640HV are precision current sense amplifiers that detect small differential voltages across a sense resistor in the presence of high input common mode voltages with a supply voltage range from 2.7V to 12V. 1 2 * * * * * * * * * Typical Values, TA = 25C High Common-Mode Voltage Range - LMP8640: -2V to 42V - LMP8640HV: -2V to 76V Supply Voltage Range: 2.7V to 12V Gain Options: 20V/V; 50V/V; 100V/V Max Gain Error: 0.25% Low Offset Voltage: 900V Input Bias Current: 13 A PSRR: 85 dB CMRR (2.1V to 42V): 103 dB Temperature Range: -40C to 125C 6-Pin SOT Package The LMP8640 accepts input signals with common mode voltage range from -2V to 42V, while the LMP8640HV accepts input signal with common mode voltage range from -2V to 76V. The LMP8640 and LMP8640HV have fixed gain for applications that demand accuracy over temperature. The LMP8640 and LMP8640HV come out with three different fixed gains 20V/V, 50V/V, 100V/V ensuring a gain accuracy as low as 0.25%. The output is buffered in order to provide low output impedance. This high side current sense amplifier is ideal for sensing and monitoring currents in DC or battery powered systems, excellent AC and DC specifications over temperature, and keeps errors in the current sense loop to a minimum. The LMP8640 and LMP8640HV are ideal choice for industrial, automotive and consumer applications, and it is available in SOT-6 package. APPLICATIONS * * * * * * High-Side Current Sense Vehicle Current Measurement Motor Controls Battery Monitoring Remote Sensing Power Management Typical Application IS + RS +IN -IN RIN + L o a d LMP8640 RIN + V + VA G ADC VOUT RG = 2*RIN V - G = 10 V/V in 20 V/V gain option G = 25 V/V in 50 V/V gain option G = 50 V/V in 100 V/V gain option 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 (c) 2010-2013, Texas Instruments Incorporated LMP8640 LMP8640HV SNOSB28F - AUGUST 2010 - REVISED APRIL 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 ESD Tolerance (4) (1) (2) (3) Human Body Model For input pins +IN, -IN 5000V For all other pins 2000V Machine Model 200V Charge device model 1250V Supply Voltage (VS = V+ - V-) 13.2V Differential Voltage +IN- (-IN) 6V Voltage at pins +IN, -IN LMP8640HV -6V to 80V LMP8640 -6V to 60V V-to V+ Voltage at VOUT pin Storage Temperature Range Junction Temperature (1) (2) (3) (4) (5) 2 -65C to 150C (5) 150C "Absolute Maximum Ratings" indicate limits beyond which damage to the device may occur, including inoperability and degradation of device reliability and/or performance. Functional operation of the device and/or non-degradation at the Absolute Maximum Ratings or other conditions beyond those indicated in the Operating Ratings is not implied. Operating Ratings indicate conditions at which the device is functional and the device should not be operated beyond such conditions. For soldering specifications,see product folder at www.ti.com and http://www.ti.com/lit/SNOA549. If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/Distributors for availability and specifications. Human Body Model, applicable std. MIL-STD-883, Method 3015.7. Machine Model, applicable std. JESD22-A115-A (ESD MM std. of JEDEC) Field-Induced Charge-Device Model, applicable std. JESD22-C101-C (ESD FICDM std. of JEDEC). The maximum power dissipation must be derated at elevated temperatures and is dictated by TJ(MAX), JA, and the ambient temperature, TA. The maximum allowable power dissipation PDMAX = (TJ(MAX) - TA)/ JA or the number given in Absolute Maximum Ratings, whichever is lower. Submit Documentation Feedback Copyright (c) 2010-2013, Texas Instruments Incorporated Product Folder Links: LMP8640 LMP8640HV LMP8640 LMP8640HV www.ti.com SNOSB28F - AUGUST 2010 - REVISED APRIL 2013 Operating Ratings (1) Supply Voltage (VS = V+ - V-) Temperature Range 2.7V to 12V (2) -40C to 125C Package Thermal Resistance (2) SOT-6 (1) (2) 96C/W "Absolute Maximum Ratings" indicate limits beyond which damage to the device may occur, including inoperability and degradation of device reliability and/or performance. Functional operation of the device and/or non-degradation at the Absolute Maximum Ratings or other conditions beyond those indicated in the Operating Ratings is not implied. Operating Ratings indicate conditions at which the device is functional and the device should not be operated beyond such conditions. The maximum power dissipation must be derated at elevated temperatures and is dictated by TJ(MAX), JA, and the ambient temperature, TA. The maximum allowable power dissipation PDMAX = (TJ(MAX) - TA)/ JA or the number given in Absolute Maximum Ratings, whichever is lower. 2.7V Electrical Characteristics (1) Unless otherwise specified, all limits ensured for at TA = 25C, VS=V+ - V-, VSENSE= +IN-(-IN), V+ = 2.7V, V- = 0V, -2V < VCM < 76V, RL = 10M. Boldface limits apply at the temperature extremes. Parameter Test Conditions VOS Input Offset Voltage TCVOS Input Offset Voltage Drift (4) IB Input Bias Current eni PSRR CMRR BW (1) (2) (3) (4) (5) (6) (5) Typ (3) -900 -1160 VCM = 2.1V (6) Max (2) Unit 900 1160 V 2.6 V/C 20 27 A VCM = 2.1V 12 f > 10 kHz 117 nV/Hz Fixed Gain LMP8640-T LMP8640HV-T 20 V/V Fixed Gain LMP8640-F LMP8640HV-F 50 V/V Fixed Gain LMP8640-H LMP8640HV-H 100 V/V Input Voltage Noise Gain AV VCM = 2.1V Min (2) (5) -0.25 -0.51 Gain error VCM = 2.1V Accuracy over temperature (5) -40C to 125C, VCM=2.1V Power Supply Rejection Ratio VCM = 2.1V, 2.7V < V+ < 12V, 85 LMP8640HV 2.1V < VCM < 42V LMP8640 2.1V < VCM< 42V 103 LMP8640HV 2.1V < VCM < 76V 95 -2V <VCM < 2V, 60 Common Mode Rejection Ratio 0.25 0.51 % 26.2 ppm/C dB dB Fixed Gain LMP8640-T LMP8640HV-T (5) DC VSENSE = 67.5 mV, CL = 30 pF,RL= 1M 950 Fixed Gain LMP8640-F LMP8640HV-F (5) DC VSENSE =27 mV, CL = 30 pF, RL= 1M 450 Fixed Gain LMP8640-H LMP8640HV-H (5) DC VSENSE = 13.5 mV, CL = 30 pF ,RL= 1M 230 kHz Electrical Table values apply only for factory testing conditions at the temperature indicated. Factory testing conditions result in very limited self-heating of the device such that TJ = TA. No specification of parametric performance is indicated in the electrical tables under conditions of internal self-heating where TJ > TA. Absolute Maximum Ratings indicate junction temperature limits beyond which the device may be permanently degraded, either mechanically or electrically. Limits are 100% production tested at 25C. Limits over the operating temperature range are ensured through correlations using statistical quality control (SQC) method. Typical values represent the most likely parametric norm 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. Offset voltage temperature drift is determined by dividing the change in VOS at the temperature extremes by the total temperature change. This parameter is ensured by design and/or characterization and is not tested in production. Positive Bias Current corresponds to current flowing into the device. Copyright (c) 2010-2013, Texas Instruments Incorporated Product Folder Links: LMP8640 LMP8640HV Submit Documentation Feedback 3 LMP8640 LMP8640HV SNOSB28F - AUGUST 2010 - REVISED APRIL 2013 www.ti.com 2.7V Electrical Characteristics (1) (continued) Unless otherwise specified, all limits ensured for at TA = 25C, VS=V+ - V-, VSENSE= +IN-(-IN), V+ = 2.7V, V- = 0V, -2V < VCM < 76V, RL = 10M. Boldface limits apply at the temperature extremes. Parameter VCM =5V, CL = 30 pF, RL = 1M, LMP8640-T LMP8640HV-T VSENSE =100mVpp, LMP8640-F LMP8640HV-F VSENSE =40mVpp, LMP8640-H LMP8640HV-H VSENSE =20mVpp, (7) (5) SR Slew Rate RIN Differential Mode Input Impedance (5) IS Typ (3) VOUT 5 k 420 600 800 VCM = -2V 2000 2500 2750 2.65 A V LMP8640-T LMP8640HV-T VCM = 2.1V 18.2 LMP8640-F LMP8640HV-F VCM = 2.1V 40 LMP8640-H LMP8640HV-H VCM = 2.1V 80 Max Output Capacitance Load (5) CLOAD Unit V/s VCM = 2.1V VCM = 2.1V Minimum Output Voltage Max (2) 1.4 Supply Current Maximum Output Voltage (7) Min (2) Test Conditions 30 mV pF The number specified is the average of rising and falling slew rates and measured at 90% to 10%. 5V Electrical Characteristics (1) Unless otherwise specified, all limits ensured for at TA = 25C, VS=V+ - V-, VSENSE= +IN-(-IN), V+ = 5V, V- = 0V, -2V < VCM < 76V, RL = 10M. Boldface limits apply at the temperature extremes. Max (2) Unit 900 1160 V VCM = 2.1V 2.6 V/C VCM = 2.1V 13 21 28 A f > 10 kHz Parameter VOS Input Offset Voltage TCVOS Input Bias Current eni PSRR (1) (2) (3) (4) (5) (6) 4 (6) Input Voltage Noise Gain AV (4) (5) (5) Typ (3) -900 -1160 VCM = 2.1V Input Offset Voltage Drift IB Min (2) Test Conditions 117 nV/Hz Fixed Gain LMP8640-T LMP8640HV-T 20 V/V Fixed Gain LMP8640-F LMP8640HV-F 50 V/V Fixed Gain LMP8640-H LMP8640HV-H 100 V/V -0.25 -0.51 Gain error VCM = 2.1V Accuracy over temperature (5) -40C to 125C, VCM=2.1V Power Supply Rejection Ratio + VCM = 2.1V, 2.7V < V < 12V, 85 0.25 0.51 % 26.2 ppm/C dB Electrical Table values apply only for factory testing conditions at the temperature indicated. Factory testing conditions result in very limited self-heating of the device such that TJ = TA. No specification of parametric performance is indicated in the electrical tables under conditions of internal self-heating where TJ > TA. Absolute Maximum Ratings indicate junction temperature limits beyond which the device may be permanently degraded, either mechanically or electrically. Limits are 100% production tested at 25C. Limits over the operating temperature range are ensured through correlations using statistical quality control (SQC) method. Typical values represent the most likely parametric norm 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. Offset voltage temperature drift is determined by dividing the change in VOS at the temperature extremes by the total temperature change. This parameter is ensured by design and/or characterization and is not tested in production. Positive Bias Current corresponds to current flowing into the device. Submit Documentation Feedback Copyright (c) 2010-2013, Texas Instruments Incorporated Product Folder Links: LMP8640 LMP8640HV LMP8640 LMP8640HV www.ti.com SNOSB28F - AUGUST 2010 - REVISED APRIL 2013 5V Electrical Characteristics (1) (continued) Unless otherwise specified, all limits ensured for at TA = 25C, VS=V+ - V-, VSENSE= +IN-(-IN), V+ = 5V, V- = 0V, -2V < VCM < 76V, RL = 10M. Boldface limits apply at the temperature extremes. Parameter CMRR BW Common Mode Rejection Ratio 103 LMP8640HV 2.1V < VCM < 76V 95 -2V <VCM < 2V, 60 950 Fixed Gain LMP8640-F LMP8640HV-F (5) DC VSENSE =27 mV, CL = 30 pF ,RL= 1M 450 Fixed Gain LMP8640-H LMP8640HV-H (5) DC VSENSE = 13.5 mV, CL = 30 pF ,RL= 1M 230 VCM =5V, CL = 30 pF, RL = 1M, LMP8640-T LMP8640HV-T VSENSE =200mVpp, LMP8640-F LMP8640HV-F VSENSE =80mVpp, LMP8640-H LMP8640HV-H VSENSE =40mVpp, 1.6 (7) (5) RIN Differential Mode Input Impedance (5) VOUT CLOAD kHz V/s k VCM = 2.1V 500 722 922 VCM = -2V 2050 2500 2750 VCM = 2.1V Minimum Output Voltage Unit 5 Supply Current Maximum Output Voltage Max (2) dB DC VSENSE = 67.5 mV, CL = 30 pF ,RL= 1M Slew Rate (7) LMP8640HV 2.1V < VCM < 42V LMP8640 2.1V < VCM< 42V Typ (3) Fixed Gain LMP8640-T LMP8640HV-T (5) SR IS Min (2) Test Conditions A 4.95 V LMP8640-T LMP8640HV-T VCM = 2.1V 18.2 LMP8640-F LMP8640HV-F VCM = 2.1V 40 LMP8640-H LMP8640HV-H VCM = 2.1V 80 Max Output Capacitance Load (5) mV 30 pF The number specified is the average of rising and falling slew rates and measured at 90% to 10%. 12V Electrical Characteristics (1) Unless otherwise specified, all limits ensured for at TA = 25C, VS=V+ - V-, VSENSE= +IN-(-IN), V+ = 12V, V- = 0V, -2V < VCM < 76V, RL = 10M. Boldface limits apply at the temperature extremes. Max (2) Unit 900 1160 V VCM = 2.1V 2.6 V/C VCM = 2.1V 13 22 28 A f > 10 kHz 117 Parameter Test Conditions VOS Input Offset Voltage TCVOS Input Offset Voltage Drift (4) Input Bias Current eni Input Voltage Noise (2) (3) (4) (5) (6) (5) (6) IB (1) VCM = 2.1V (5) Min (2) Typ (3) -900 -1160 nV/Hz Electrical Table values apply only for factory testing conditions at the temperature indicated. Factory testing conditions result in very limited self-heating of the device such that TJ = TA. No specification of parametric performance is indicated in the electrical tables under conditions of internal self-heating where TJ > TA. Absolute Maximum Ratings indicate junction temperature limits beyond which the device may be permanently degraded, either mechanically or electrically. Limits are 100% production tested at 25C. Limits over the operating temperature range are ensured through correlations using statistical quality control (SQC) method. Typical values represent the most likely parametric norm 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. Offset voltage temperature drift is determined by dividing the change in VOS at the temperature extremes by the total temperature change. This parameter is ensured by design and/or characterization and is not tested in production. Positive Bias Current corresponds to current flowing into the device. Copyright (c) 2010-2013, Texas Instruments Incorporated Product Folder Links: LMP8640 LMP8640HV Submit Documentation Feedback 5 LMP8640 LMP8640HV SNOSB28F - AUGUST 2010 - REVISED APRIL 2013 www.ti.com 12V Electrical Characteristics(1) (continued) Unless otherwise specified, all limits ensured for at TA = 25C, VS=V+ - V-, VSENSE= +IN-(-IN), V+ = 12V, V- = 0V, -2V < VCM < 76V, RL = 10M. Boldface limits apply at the temperature extremes. Parameter Gain AV PSRR CMRR BW Fixed Gain LMP8640-F LMP8640HV-F 50 V/V Fixed Gain LMP8640-H LMP8640HV-H 100 V/V VCM = 2.1V Accuracy over temperature (5) -40C to 125C, VCM=2.1V + Power Supply Rejection Ratio Common Mode Rejection Ratio VCM = 2.1V, 2.7V < V < 12V, 85 LMP8640HV 2.1V < VCM < 42V LMP8640 2.1V < VCM< 42V 103 LMP8640HV 2.1V < VCM < 76V 95 -2V <VCM < 2V, 60 950 Fixed Gain LMP8640-F LMP8640HV-F (5) DC VSENSE =27 mV, CL = 30 pF ,RL= 1M 450 Fixed Gain LMP8640-H LMP8640HV-H (5) DC VSENSE = 13.5 mV, CL = 30 pF ,RL= 1M 230 VCM =5V, CL = 30 pF, RL = 1M, LMP8640-T LMP8640HV-T VSENSE =500mVpp, LMP8640-F LMP8640HV-F VSENSE =200mVpp, LMP8640-H LMP8640HV-H VSENSE =100mVpp, 1.8 Max Output Capacitance Load 26.2 ppm/C kHz V/s 5 k VCM = 2.1V 720 1050 1250 VCM = -2V 2300 2800 3000 Supply Current VCM = 2.1V Minimum Output Voltage % dB DC VSENSE = 67.5 mV, CL = 30 pF ,RL= 1M (7) (5) 0.25 0.51 dB Fixed Gain LMP8640-T LMP8640HV-T (5) Maximum Output Voltage 6 -0.25 -0.51 Gain error Differential Mode Input Impedance (5) CLOAD Unit V/V RIN VOUT Max (2) 20 Slew Rate (7) (8) Typ (3) Fixed Gain LMP8640-T LMP8640HV-T SR IS Min (2) Test Conditions 11.85 V LMP8640-T LMP8640HV-T VCM = 2.1V 18.2 LMP8640-F LMP8640HV-F VCM = 2.1V 40 LMP8640-H LMP8640HV-H VCM = 2.1V 80 (8) A 30 mV pF The number specified is the average of rising and falling slew rates and measured at 90% to 10%. This parameter is ensured by design and/or characterization and is not tested in production. Submit Documentation Feedback Copyright (c) 2010-2013, Texas Instruments Incorporated Product Folder Links: LMP8640 LMP8640HV LMP8640 LMP8640HV www.ti.com SNOSB28F - AUGUST 2010 - REVISED APRIL 2013 DEVICE INFORMATION Block Diagram +IN -IN RIN LMP8640 RIN + LMP8640HV + V G VOUT RG = 2*RIN V - Connection Diagram Top View VOUT V - +IN 1 2 LMP8640 LMP8640HV 3 + 6 V 5 NC 4 -IN Figure 1. 6-Pin SOT Package see package number DDC0006A Table 1. Pin Descriptions Pin Name 1 VOUT Description 2 V- 3 +IN Positive Input 4 -IN Negative Input 5 NC Not Connected 6 V+ Positive Supply Voltage Single Ended Output Negative Supply Voltage Copyright (c) 2010-2013, Texas Instruments Incorporated Product Folder Links: LMP8640 LMP8640HV Submit Documentation Feedback 7 LMP8640 LMP8640HV SNOSB28F - AUGUST 2010 - REVISED APRIL 2013 www.ti.com Typical Performance Characteristics Unless otherwise specified: TA = 25C, VS=V+-V-, VSENSE= +IN - (-IN), RL = 10 M. Supply Curent vs. Supply Voltage 2300 2400 2100 VCM=-2V 2500 2300 2200 2100 25C -40C 125C 1700 IS (PA) 125C 1300 1100 600 500 8.0 10.6 -40C 700 500 400 5.3 25C 900 300 -2 -1 0 13.2 | 700 300 2.7 1500 1 2 3 VS (V) VCM (V) Figure 2. 2300 Figure 3. Supply Current vs. VCM 1700 1900 125C IS (PA) IS (PA) 2100 1300 1700 -40C 900 1100 900 500 700 | 700 1 2 3 125 C 1500 1300 25C 300 -2 -1 0 VS = 12V 2300 1900 1100 Supply Current vs. VCM 2500 VS = 5V 2100 1500 25C -40C 500 -2 -1 0 4 16 28 40 52 64 76 1 2 VCM (V) 4 16 28 40 52 64 76 Figure 5. CMRR vs. VCM (Gain 20V/V) CMRR vs. VCM (Gain 50V/V) 140 130 130 120 25C 120 CMRR (dB) CMRR (dB) 3 VCM (V) Figure 4. 140 4 16 28 40 52 64 76 | | 800 VS = 2.7V 1900 VCM = 2.1V 1900 | IS (PA) 2000 Supply Current vs. VCM 125 C 110 -40C 100 -40C 25C 110 100 90 90 VS = 5V 80 -2 11 24 37 50 63 VS = 5V 76 80 -2 11 VCM (V) Submit Documentation Feedback 24 37 50 63 76 V CM (V) Figure 6. 8 125C Figure 7. Copyright (c) 2010-2013, Texas Instruments Incorporated Product Folder Links: LMP8640 LMP8640HV LMP8640 LMP8640HV www.ti.com SNOSB28F - AUGUST 2010 - REVISED APRIL 2013 Typical Performance Characteristics (continued) Unless otherwise specified: TA = 25C, VS=V+-V-, VSENSE= +IN - (-IN), RL = 10 M. CMRR vs. VCM (Gain 100V/V) Input Voltage Offset vs. VCM 200 140 VS = 5V -40C 150 130 CMRR (dB) 25C VOS (PV) 100 120 125C 110 125 C 50 0 25C -50 100 -100 90 -40C -150 V S = 5V 80 -2 11 24 37 50 63 -200 -2 76 11 24 37 0 0 -100 -200 -40C -40C -200 125C -300 (A) IB (PV) (A) IB (PV) Ibias vs. VCM 100 -100 25C 125 C -300 -400 -500 -500 -600 -600 25C -700 -700 -800 -800 VS = 2.7V -900 -2 -1 0 1 2 3 VS = 5V -900 -2 -1 0 4 16 28 40 52 64 76 1 2 3 4 16 28 40 52 64 76 VCM (V) VCM (V) Figure 10. Figure 11. Ibias vs. VCM 100 Gain vs. Frequency 50 0 -100 76 Figure 9. Ibias vs. VCM -400 63 V CM (V) V CM (V) Figure 8. 100 50 VS =5V, VCM=5V GAIN 100V/V -40C 40 125C -300 -400 GAIN (dB) IB (PV) (A) -200 25C -500 30 GAIN 50V/V -600 20 GAIN 20V/V -700 -800 -900 -2 -1 0 VS = 12V 1 2 3 4 16 28 40 52 64 76 10 100 VCM (V) 1k 10k 100k 1M 10M FREQUENCY (Hz) Figure 12. Figure 13. Copyright (c) 2010-2013, Texas Instruments Incorporated Product Folder Links: LMP8640 LMP8640HV Submit Documentation Feedback 9 LMP8640 LMP8640HV SNOSB28F - AUGUST 2010 - REVISED APRIL 2013 www.ti.com Typical Performance Characteristics (continued) 13.0 12.0 11.0 10.0 9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 0 Output voltage vs. VSENSE Output voltage vs. VSENSE (ZOOM close to 0V) 300 VS =12V, VCM =12V V S=12V, VCM=12V 250 GAIN 100V/V 200 VOUT (mV) VOUT (V) Unless otherwise specified: TA = 25C, VS=V+-V-, VSENSE= +IN - (-IN), RL = 10 M. GAIN 100V/V GAIN 50V/V 150 100 GAIN 20V/V GAIN 50V/V 50 GAIN 20V/V 100 200 300 400 500 0 -3 600 -2 VSENSE (mV) -1 0 1 2 3 VSENSE (mV) Figure 14. Figure 15. Large Step response Small Step response VSENSE GAIN 50V/V GAIN 100V/V GAIN 50V/V GAIN 20V/V GAIN 20V/V VSENS E (10 mV/DIV) GAIN 100 VOUT (100 mV/DIV) VS ENS E (20 mV/DIV) VOUT (500 mV/DIV) V SENSE V S = 5V, VCM = 12V VS =12V, VCM =12V TIME (2 Ps/DIV) TIME (2 Ps/DIV) Figure 16. Figure 17. Settling time (fall) Settling time (rise) VS = 5V, VCM = 12V GAIN 100V/V GAIN 100 V/V V SENSE GAIN 50V/V GAIN 20V/V VSE NSE (10 mV/DIV) GAIN 20V/V VOUT (100 mV/DIV) GAIN 50V/V V SE NS E (10 mV/DIV) V OUT (100 mV/DIV) V SENSE VS = 5V, V CM = 12V TIME (400 ns /DIV) TIME (400 ns/DIV) Figure 18. 10 Submit Documentation Feedback Figure 19. Copyright (c) 2010-2013, Texas Instruments Incorporated Product Folder Links: LMP8640 LMP8640HV LMP8640 LMP8640HV www.ti.com SNOSB28F - AUGUST 2010 - REVISED APRIL 2013 Typical Performance Characteristics (continued) Unless otherwise specified: TA = 25C, VS=V+-V-, VSENSE= +IN - (-IN), RL = 10 M. V OUT VCM VCM (5V/DIV) VCM (5V/DIV) V CM Common mode step response (fall) VOUT (50 mV/DIV) V OUT (20 mV/DIV) Common mode step response (rise) VOUT VS = 5V, GAIN 20 V/V VS = 5V, GAIN 20 V/V TIME (4 es/DIV) TIME (4 es/DIV) Figure 20. Figure 21. Load regulation (Sinking) 2.6 2.505 Load regulation (Sourcing) VS =5V, VCM=12V 2.504 2.5 GAIN 100 V/V 2.4 2.502 GAIN 50 GAIN 100V/V 2.3 V OUT (V) V OUT (V) 2.503 2.2 2.501 GAIN 50 2.1 GAIN 20V/V 2.500 2.0 GAIN 20V/V 1.9 0 2.499 1 2 3 4 VS =5V, VCM=12V 2.498 0 1 2 3 4 5 6 7 8 9 5 6 7 8 9 10 I OUT (mA) 10 I OUT (mA) Figure . Figure 22. AC PSRR vs. Frequency AC CMRR vs. Frequency 110 100 V S = 5V, V CM = 12V VS = 5V, VCM = 12V 90 CMRR (dB) PSRR (dB) 80 60 GAIN 20V/V 40 70 GAIN 100V/V 50 GAIN 50V/V GAIN 100 V/V 20 30 GAIN 20V/V GAIN 50V/V 0 10 100 1k 10k 100k 1M 10 1 FREQUENCY (Hz) Figure 23. 10 100 1k 10k 100k Frequency (Hz) Figure 24. Copyright (c) 2010-2013, Texas Instruments Incorporated Product Folder Links: LMP8640 LMP8640HV Submit Documentation Feedback 11 LMP8640 LMP8640HV SNOSB28F - AUGUST 2010 - REVISED APRIL 2013 www.ti.com APPLICATION INFORMATION GENERAL The LMP8640 and LMP8640HV are single supply high side current sense amplifiers with a fixed gain of 20V/V, 50V/V, 100V/V and a common mode voltage range of -2V to 42V or -2V to 76V depending on the grade. THEORY OF OPERATION As seen from the picture below, the current flowing through RS develops a voltage drop equal to VSENSE across RS. The high impedance inputs of the amplifier doesn't conduct this current and the high open loop gain of the sense amplifier forces its non-inverting input to the same voltage as the inverting input. In this way the voltage drop across RIN matches VSENSE. A current proportional to IS according to the following relation: IG = VSENSE/RIN = RS*IS/RIN , (1) flows entirely in the internal gain resistor RG developing a voltage drop equal to VRG = IG *RG = (VSENSE/RIN) *RG = ((RS*IS)/RIN)*RG (2) This voltage is buffered and showed at the output with a very low impedance allowing a very easy interface of the LMP8640 with other ICs (ADC, C...). VOUT = 2*(RS*IS)*G, (3) where G=RG/RIN = 10V/V, 25V/V, 50V/V, according to the gain options. VSENSE Is + Rs +IN -IN RIN + LMP8640 RIN L o a d + V IG G VOUT RG = 2*RIN V - Figure 25. Current Monitor SELECTION OF THE SHUNT RESISTOR The value chosen for the shunt resistor, RS, depends on the application. It plays a big role in a current sensing system and must be chosen with care. The selection of the shunt resistor needs to take in account the smallsignal accuracy, the power dissipated and the voltage loss across the shunt itself. In applications where a small current is sensed, a bigger value of RS is selected to minimize the error in the proportional output voltage. Higher resistor value improves the SNR at the input of the current sense amplifier and hence gives an accurate output. Similarly when high current is sensed, the power losses in RS can be significant so a smaller value of RS is suggested. In this condition is required to take in account also the power rating of RS resistor. The low input offset of the LMP8640 allows the use of small sense resistors to reduce power dissipation still providing a good input dynamic range. The input dynamic range is the ratio expressed in dB between the maximum signal that can be measured and the minimum signal that can be detected, usually the input offset is the principal limiting factor. 12 Submit Documentation Feedback Copyright (c) 2010-2013, Texas Instruments Incorporated Product Folder Links: LMP8640 LMP8640HV LMP8640 LMP8640HV www.ti.com SNOSB28F - AUGUST 2010 - REVISED APRIL 2013 DRIVING ADC The input stage of an Analog to Digital converter can be modeled with a resistor and a capacitance versus ground. So if the voltage source doesn't have a low impedance an error in the amplitude's measurement will occur. In this case a buffer is needed to drive the ADC. The LMP8640 has an internal output buffer able to drive a capacitance load up to 30 pF or the input stage of an ADC. If required an external low pass RC filter can be added at the output of the LMP8640 to reduce the noise and the bandwidth of the current sense. IS + RS +IN -IN RIN + L o a d LMP8640 RIN + V + VA RF G ADC VOUT CF RG = 2*RIN - V Figure 26. LMP8640 to ADC Interface DESIGN EXAMPLE For example in a current monitor application is required to measure the current sunk by a load (peak current 10A) with a resolution of 10mA and 0.5% of accuracy. The 10bit analog to digital converter accepts a max input voltage of 4.1V. Moreover in order to not burn much power on the shunt resistor it needs to be less than 10m. In the table below are summarized the other working condition. Working Condition Value Min Max Supply Voltage 5V 5.5V Common mode Voltage 48V 70V Temperature 0C 70C Signal BW 50kHz First step - LMP8640 / LMP8640HV selection The required common mode voltage of the application implies that the right choice is the LMP8640HV (High common mode voltage up tp 76V). Second step - Gain option selection We can choose between three gain option (20V/V, 50V/V, 100V/V). considering the max input voltage of the ADC (4.1V) , the max Sense voltage across the shunt resistor is evaluated according the following formula: VSENSE= (MAX Vin ADC) / Gain; hence the max VSENSE will be 205mV, 82mV, 41mV respectively. The shunt resistor are then evaluated considering the maximum monitored current : RS = (max VSENSE) / I_MAX For each gain option the max shunt resistors are the following : 20.5m, 8.2m, 4.1m respectively. Copyright (c) 2010-2013, Texas Instruments Incorporated Product Folder Links: LMP8640 LMP8640HV Submit Documentation Feedback 13 LMP8640 LMP8640HV SNOSB28F - AUGUST 2010 - REVISED APRIL 2013 www.ti.com One of the project constraints requires RS<10m, it means that the 20.5m will be discarded and hence the 50V/V and 100V/V gain options are still in play. Third step - Shunt resistor selection At this point an error budget calculation, considering the calibration of the Gain, Offset, CMRR, and PSRR, helps in the selection of the shunt resistor. In the table below the contribution of each error source is calculated considering the values of the Electrical Characteristics table at 5V supply. Table 2. Resolution Calculation ERROR SOURCE RS = 4.1m RS = 8.1m CMRR calibrated ad mid VCM range 77.9V 77.9V PSRR calibrated at 5V 8.9V 8.9V Total error (squared sum of contribution) 78V 78V 19.2mA 9.6mA Resolution (Total error / RS) Table 3. Accuracy Calculation ERROR SOURCE RS = 4.1m RS = 8.1m 182V 182V Nosie 216V 216V Gain drift 75.2V 151V Total error (squared sum of contribution) 293V 320V 0.7% 0.4% Tc Vos Accuracy 100*(Max_VSENSE / Total Error) From the tables above is clear that the 8.2m shunt resistor allows the respect of the project's constraints. The power burned on the Shunt is 820mW at 10A. 14 Submit Documentation Feedback Copyright (c) 2010-2013, Texas Instruments Incorporated Product Folder Links: LMP8640 LMP8640HV PACKAGE OPTION ADDENDUM www.ti.com 15-Apr-2013 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish (2) MSL Peak Temp Op Temp (C) Top-Side Markings (3) (4) LMP8640HVMK-F/NOPB ACTIVE SOT DDC 6 1000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AD6A LMP8640HVMK-H/NOPB ACTIVE SOT DDC 6 1000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AF6A LMP8640HVMK-T/NOPB ACTIVE SOT DDC 6 1000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AB6A LMP8640HVMKE-F/NOPB ACTIVE SOT DDC 6 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AD6A LMP8640HVMKE-H/NOPB ACTIVE SOT DDC 6 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AF6A LMP8640HVMKE-T/NOPB ACTIVE SOT DDC 6 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AB6A LMP8640HVMKX-F/NOPB ACTIVE SOT DDC 6 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AD6A LMP8640HVMKX-H/NOPB ACTIVE SOT DDC 6 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AF6A LMP8640HVMKX-T/NOPB ACTIVE SOT DDC 6 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AB6A LMP8640MK-F/NOPB ACTIVE SOT DDC 6 1000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AC6A LMP8640MK-H/NOPB ACTIVE SOT DDC 6 1000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AE6A LMP8640MK-T/NOPB ACTIVE SOT DDC 6 1000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AA6A LMP8640MKE-F/NOPB ACTIVE SOT DDC 6 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AC6A LMP8640MKE-H/NOPB ACTIVE SOT DDC 6 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AE6A LMP8640MKE-T/NOPB ACTIVE SOT DDC 6 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AA6A LMP8640MKX-F/NOPB ACTIVE SOT DDC 6 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AC6A LMP8640MKX-H/NOPB ACTIVE SOT DDC 6 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 AE6A Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com Orderable Device 15-Apr-2013 Status (1) LMP8640MKX-T/NOPB ACTIVE Package Type Package Pins Package Drawing Qty SOT DDC 6 3000 Eco Plan Lead/Ball Finish (2) Green (RoHS & no Sb/Br) MSL Peak Temp Op Temp (C) Top-Side Markings (3) CU NIPDAU Level-1-260C-UNLIM (4) -40 to 125 AA6A (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) Multiple Top-Side Markings will be inside parentheses. Only one Top-Side 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 Top-Side Marking for that device. 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. 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Addendum-Page 2 Samples PACKAGE MATERIALS INFORMATION www.ti.com 24-Apr-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 LMP8640HVMK-F/NOPB SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640HVMK-H/NOPB SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640HVMK-T/NOPB SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640HVMKE-F/NOPB SOT DDC 6 250 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640HVMKE-H/NOP B SOT DDC 6 250 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640HVMKE-T/NOPB SOT DDC 6 250 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640HVMKX-F/NOPB SOT DDC 6 3000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640HVMKX-H/NOP B SOT DDC 6 3000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640HVMKX-T/NOPB SOT DDC 6 3000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640MK-F/NOPB SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640MK-H/NOPB SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640MK-T/NOPB SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640MKE-F/NOPB SOT DDC 6 250 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640MKE-H/NOPB SOT DDC 6 250 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640MKE-T/NOPB SOT DDC 6 250 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640MKX-F/NOPB SOT DDC 6 3000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LMP8640MKX-H/NOPB SOT DDC 6 3000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 24-Apr-2013 Device LMP8640MKX-T/NOPB Package Package Pins Type Drawing SOT DDC 6 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 3000 178.0 8.4 3.2 B0 (mm) K0 (mm) P1 (mm) 3.2 1.4 4.0 W Pin1 (mm) Quadrant 8.0 Q3 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LMP8640HVMK-F/NOPB SOT DDC 6 1000 210.0 185.0 35.0 LMP8640HVMK-H/NOPB SOT DDC 6 1000 210.0 185.0 35.0 LMP8640HVMK-T/NOPB SOT DDC 6 1000 210.0 185.0 35.0 LMP8640HVMKE-F/NOPB SOT DDC 6 250 210.0 185.0 35.0 LMP8640HVMKE-H/NOPB SOT DDC 6 250 210.0 185.0 35.0 LMP8640HVMKE-T/NOPB SOT DDC 6 250 210.0 185.0 35.0 LMP8640HVMKX-F/NOPB SOT DDC 6 3000 210.0 185.0 35.0 LMP8640HVMKX-H/NOPB SOT DDC 6 3000 210.0 185.0 35.0 LMP8640HVMKX-T/NOPB SOT DDC 6 3000 210.0 185.0 35.0 LMP8640MK-F/NOPB SOT DDC 6 1000 210.0 185.0 35.0 LMP8640MK-H/NOPB SOT DDC 6 1000 210.0 185.0 35.0 LMP8640MK-T/NOPB SOT DDC 6 1000 210.0 185.0 35.0 LMP8640MKE-F/NOPB SOT DDC 6 250 210.0 185.0 35.0 LMP8640MKE-H/NOPB SOT DDC 6 250 210.0 185.0 35.0 LMP8640MKE-T/NOPB SOT DDC 6 250 210.0 185.0 35.0 LMP8640MKX-F/NOPB SOT DDC 6 3000 210.0 185.0 35.0 Pack Materials-Page 2 PACKAGE MATERIALS INFORMATION www.ti.com 24-Apr-2013 Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LMP8640MKX-H/NOPB SOT DDC 6 3000 210.0 185.0 35.0 LMP8640MKX-T/NOPB SOT DDC 6 3000 210.0 185.0 35.0 Pack Materials-Page 3 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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