LT6100 Precision, Gain Selectable High Side Current Sense Amplifier DESCRIPTION FEATURES Input Offset Voltage: 300µV (Max) n Sense Inputs Up to 48V n0.5% Gain Accuracy n Pin Selectable Gain: 10, 12.5, 20, 25, 40, 50V/V n Separate Power Supply: 2.7V to 36V n Operating Current: 60µA n Sense Input Current (V CC Powered Down): 1nA n Reverse Battery Protected to –48V n Buffered Output n Noise Filtering Input n–40°C to 125°C Operating Temperature Range n Available in 8-Lead DFN and MSOP Packages The LT®6100 is a complete micropower, precision, high side current sense amplifier. The LT6100 monitors unidirectional currents via the voltage across an external sense resistor. Fixed gains of 10, 12.5, 20, 25, 40, 50V/V are obtained by simply strapping or floating two gain select pins. Gain accuracy is better than 0.5% for all gains. n The LT6100 sense inputs have a voltage range that extends from 4.1V to 48V, and can withstand a differential voltage of the full supply. This makes it possible to monitor the voltage across a MOSFET switch or a fuse. The part can also withstand a reverse battery condition on the inputs. Input offset is a low 300µV. CMRR and PSRR are in excess of 105dB, resulting in a wide dynamic range. A filter pin is provided to easily implement signal filtering with a single capacitor. APPLICATIONS n n n n Battery Monitoring Fuse Monitoring Portable and Cellular Phones Portable Test/Measurement Systems L, LT, LTC, LTM, Linear Technology, the Linear logo and Over-The-Top are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. The LT6100 has a separate supply input, which operates from 2.7V to 36V and draws only 60µA. When VCC is powered down, the sense pins are biased off. This prevents loading of the monitored circuit, irrespective of the sense voltage. The LT6100 is available in an 8-lead DFN and MSOP package. TYPICAL APPLICATION 0A to 33A High Side Current Monitor with 12kHz Frequency Rolloff 3V 2 LT6100 VCC 1.5 7 6 A4 A2 + 8 VS VOUT 5 RSENSE 3mΩ – 1 VS LOAD CONFIGURED FOR GAIN = 25V/V VEE FIL 4 3 VOUT = 2.5V ISENSE = 33A INPUT OFFSET VOLTAGE (mV) 4.4V TO 48V SUPPLY Input Offset Voltage vs VS Sense Input Voltage 6100 TA01a 1.0 0.5 0 –0.5 –1.0 –1.5 220pF VSENSE = 100mV VCC = 3V TA = 25°C 0 5 10 15 20 25 30 35 40 45 50 VS SENSE INPUT VOLTAGE (V) 6100 TA01b 6100fd For more information www.linear.com/LT6100 1 LT6100 ABSOLUTE MAXIMUM RATINGS (Notes 1, 2) Differential Sense Voltage....................................... ±48V Total VS+, VS – to VEE ................................................ 48V Total VCC Supply Voltage from VEE .......................... 36V Output Voltage................................ (VEE) to (VEE + 36V) Output Short-Circuit Duration (Note 3)......... Continuous Operating Temperature Range (Note 4) LT6100C .............................................–40°C to 85°C LT6100I ...............................................–40°C to 85°C LT6100H ........................................... –40°C to 125°C Specified Temperature Range (Note 5) LT6100C ................................................. 0°C to 70°C LT6100I ...............................................–40°C to 85°C LT6100H ........................................... –40°C to 125°C Storage Temperature Range............................................ DFN..................................................... –65°C to 125°C MSOP................................................. –65°C to 150°C Lead Temperature (Soldering, 10 sec) MSOP............................................................... 300°C PACKAGE/ORDER INFORMATION TOP VIEW VS– 1 VCC 2 FIL 3 8 9 VEE 4 TOP VIEW VS+ 7 A4 6 A2 5 VOUT VS– VCC FIL VEE 1 2 3 4 8 7 6 5 VS+ A4 A2 VOUT MS8 PACKAGE 8-LEAD PLASTIC MSOP DD PACKAGE 8-LEAD (3mm × 3mm) PLASTIC DFN TJMAX = 150°C, θJA = 250°C/W TJMAX = 125°C, θJA = 43°C/W EXPOSED PAD (PIN 9) IS VEE, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LT6100CDD#PBF LT6100CDD#TRPBF LBMW 8-Lead (3mm × 3mm) Plastic DFN 0°C to 70°C LT6100IDD#PBF LT6100IDD#TRPBF LBMW 8-Lead (3mm × 3mm) Plastic DFN –40°C to 85°C LT6100HDD#PBF LT6100HDD#TRPBF LBMW 8-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C LT6100CMS8#PBF LT6100CMS8#TRPBF LTBMV 8-Lead Plastic MS8 0°C to 70°C LT6100IMS8#PBF LT6100IMS8#TRPBF LTBMV 8-Lead Plastic MS8 –40°C to 85°C LT6100HMS8#PBF LT6100HMS8#TRPBF LTBMV 8-Lead Plastic MS8 –40°C to 125°C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.Consult LTC Marketing for information on nonstandard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ 6100fd 2 For more information www.linear.com/LT6100 LT6100 ELECTRICAL CHARACTERISTICS The l denotes specifications which apply over the temperature range 0°C ≤ TA ≤ 70°C (LT6100C), otherwise specifications are TA = 25°C. VCC = 5V, VEE = 0V, VS+ = VCC + 1.4V unless otherwise specified. (Note 5) SYMBOL PARAMETER CONDITIONS VS–, VS+ Sense Amplifier Supply Voltage VCC = 2.7V l 4.1 VSENSE Input Sense Voltage Full Scale VSENSE = VS+ – VS–, VCC = 3V, AV = 10V/V VSENSE = VS+ – VS–, VCC = 5V, AV = 10V/V l l 110 300 VOS Input Offset Voltage (MS Package) IOUT = 0 –300 –500 ±80 l 300 500 µV µV –350 –550 ±80 l 350 550 µV µV 0.5 3 Input Offset Voltage (DD Package) IOUT = 0 VOS TC Temperature Coefficient of VOS (Note 6) AV Gain, VOUT/VSENSE VSENSE = 50mV to 80mV, AV = 10V/V LT6100MS8 LT6100DD8 VS = 48V, VSENSE = 50mV to 80mV, AV = 10V/V Output Voltage Gain Error (Note 7) VCC PSRR l VS Sense Input Common Mode Rejection Ratio VSENSE = 50mV, VCC = 2.7V, VS = 4.1V to 36V VCC Supply Rejection Ratio VSENSE = 50mV, VS = 36V, VCC = 3V to 30V VCC Supply Voltage VCC BW Bandwidth AV = 10V/V, fO = –3dB, VCC = 15V AV = 50V/V, fO = –3dB, VCC = 15V tS Output Settling to 1% Final Value VSENSE = 10mV to 100mV TYP MAX 48 UNITS V mV mV µV/°C l 9.95 9.94 9.90 10.05 10.06 10.10 V/V V/V V/V l 9.90 10.10 V/V l –0.5 –0.6 –1.0 0.5 0.6 1.0 % % % l –1.0 1.0 % l 105 100 120 120 dB dB l 105 100 120 120 dB dB l 2.7 VSENSE = 50mV to 80mV, AV = 10, 12.5, 20, 25, 40, 50V/V LT6100MS8 LT6100DD8 VS = 48V, VSENSE = 50mV to 80mV, AV = 10, 12.5, 20, 25, 40, 50V/V VS CMRR MIN 100 20 36 150 50 V kHz kHz 15 µs IS+(O), IS–(O) Sense Input Current VSENSE = 0V l 4.5 10 µA ICC(O) VCC Supply Current VSENSE = 0V l 60 130 µA SR Slew Rate (Note 8) VCC = 15V, VSENSE = 26mV to 380mV, AV = 50V/V l 0.03 0.02 0.05 0.05 V/µs V/µs 8 15 mA 50 60 V Short-Circuit Current ISC+, ISC– Reverse VS Supply IS(TOTAL) = –200µA, VCC = Open l VO(MIN) Minimum Output Voltage VSENSE = 0V, No Load VSENSE = VS+ – VS– = –100mV, AV = 50V/V, No Load l 15 15 30 25 mV mV VO(MAX) Output High (Referred to VCC) AV = 50V/V, VSENSE = 100mV, IL = 0 VSENSE = 100mV, IL = 100µA VSENSE = 100mV, IL = 500µA VSENSE = 100mV, IL = 1mA l l l l 75 85 125 175 125 150 250 400 mV mV mV mV VCC = 0V, VS = 48V, VSENSE = 0V l 0.001 1 µA ISC IS+, IS– (Off) Sense Input Current (Power Down) 6100fd For more information www.linear.com/LT6100 3 LT6100 ELECTRICAL CHARACTERISTICS The l denotes specifications which apply over the temperature range –40°C ≤ TA ≤ 85°C (LT6100I), otherwise specifications are TA = 25°C. VCC = 5V, VEE = 0V, VS+ = VCC + 1.4V unless otherwise specified. (Note 5) SYMBOL PARAMETER CONDITIONS VS–, VS+ Sense Amplifier Supply Voltage VCC = 2.7V l 4.1 VSENSE Input Sense Voltage Full Scale VSENSE = VS+ – VS–, VCC = 3V, AV = 10V/V VSENSE = VS+ – VS–, VCC = 5V, AV = 10V/V l l 110 300 VOS Input Offset Voltage (MS Package) IOUT = 0 –300 –550 ±80 l 300 550 µV µV –350 –600 ±80 l 350 600 µV µV 0.5 3 Input Offset Voltage (DD Package) IOUT = 0 VOS TC Temperature Coefficient of VOS (Note 6) AV Gain, VOUT/VSENSE VSENSE = 50mV to 80mV, AV = 10V/V LT6100MS8 LT6100DD8 VS = 48V, VSENSE = 50mV to 80mV, AV = 10V/V Output Voltage Gain Error (Note 7) VCC PSRR l VS Sense Input Common Mode Rejection Ratio VSENSE = 50mV, VCC = 2.7V, VS = 4.1V to 36V VCC Supply Rejection Ratio VSENSE = 50mV, VS = 36V, VCC = 3V to 30V TYP MAX 48 UNITS V mV mV µV/°C l 9.95 9.94 9.90 10.05 10.06 10.10 V/V V/V V/V l 9.90 10.10 V/V l –0.5 –0.6 –1.0 0.5 0.6 1.0 % % % l –1.0 1.0 % l 105 100 120 120 dB dB l 105 100 120 120 dB dB l 2.7 VSENSE = 50mV to 80mV, AV = 10, 12.5, 20, 25, 40, 50V/V LT6100MS8 LT6100DD8 VS = 48V, VSENSE = 50mV to 80mV, AV = 10, 12.5, 20, 25, 40, 50V/V VS CMRR MIN VCC Supply Voltage VCC BW Bandwidth AV = 10V/V, fO = –3dB, VCC = 15V AV = 50V/V, fO = –3dB, VCC = 15V tS Output Settling to 1% Final Value VSENSE = 10mV to 100mV IS+(O), IS–(O) Sense Input Current VSENSE = 0V l 4.5 10 µA ICC(O) Supply Current VSENSE = 0V l 60 145 µA SR Slew Rate (Note 8) VCC = 15V, VSENSE = 26mV to 380mV, AV = 50V/V 100 20 l 36 V 150 50 kHz kHz 15 µs 0.03 0.02 0.05 0.05 V/µs V/µs 8 15 mA ISC Short-Circuit Current ISC+, ISC– Reverse VS Supply IS(TOTAL) = –200µA, VCC = Open l VO(MIN) Minimum Output Voltage VSENSE = 0V, No Load VSENSE = VS+ – VS– = –100mV, AV = 50V/V, No Load l 15 15 30 25 mV mV VO(MAX) Output High (Referred to VCC) AV = 50V/V, VSENSE = 100mV, IL = 0 VSENSE = 100mV, IL = 100µA VSENSE = 100mV, IL = 500µA VSENSE = 100mV, IL = 1mA l l l l 75 85 125 175 125 150 250 400 mV mV mV mV IS+, IS– (Off) Sense Input Current (Power Down) VCC = 0V, VS = 48V, VSENSE = 0V l 0.001 1 µA 50 60 V 6100fd 4 For more information www.linear.com/LT6100 LT6100 ELECTRICAL CHARACTERISTICS The l denotes specifications which apply over the temperature range –40°C ≤ TA ≤ 125°C (LT6100H), otherwise specifications are TA = 25°C. VCC = 5V, VEE = 0V, VS+ = VCC + 1.4V unless otherwise specified. (Note 5) SYMBOL PARAMETER CONDITIONS VS–, VS+ Sense Amplifier Supply Voltage VSENSE Input Sense Voltage Full Scale VOS Input Offset Voltage (MS Package) IOUT = 0 Input Offset Voltage (DD Package) 4.1 110 300 –300 –600 ±80 l 300 600 µV µV –350 –650 ±80 l 350 650 µV µV 0.5 5 IOUT = 0 AV Gain, VOUT/VSENSE VSENSE = 50mV to 80mV, AV = 10V/V LT6100MS8 LT6100DD8 VS = 48V, VSENSE = 50mV to 80mV, AV = 10V/V l VS Sense Input Common Mode Rejection Ratio VSENSE = 50mV, VCC = 2.7V, VS = 4.1V to 36V VCC Supply Rejection Ratio VSENSE = 50mV, VS = 36V, VCC = 3V to 30V VCC Supply Voltage VCC BW Bandwidth AV = 10V/V, fO = –3dB, VCC = 15V AV = 50V/V, fO = –3dB, VCC = 15V V mV mV µV/°C l 9.95 9.94 9.90 10.05 10.06 10.10 V/V V/V V/V l 9.90 10.10 V/V l –0.5 –0.6 –1.0 0.5 0.6 1.0 % % % l –1.0 1.0 % l 105 100 120 120 dB dB l 105 95 120 120 dB dB VSENSE = 50mV to 80mV, AV = 10, 12.5, 20, 25, 40, 50V/V LT6100MS8 LT6100DD8 VS = 48V, VSENSE = 50mV to 80mV, AV = 10, 12.5, 20, 25, 40, 50V/V 48 UNITS l l (Note 6) VCC PSRR MAX VSENSE = VS+ – VS–, VCC = 3V, AV = 10V/V VSENSE = VS+ – VS–, VCC = 5V, AV = 10V/V Temperature Coefficient of VOS VS CMRR TYP VCC = 2.7V VOS TC Output Voltage Gain Error (Note 7) MIN l l 2.7 100 20 tS Output Settling to 1% Final Value VSENSE = 10mV to 100mV IS+(O), IS–(O) Sense Input Current VSENSE = 0V l ICC(O) Supply Current VSENSE = 0V l SR Slew Rate (Note 8) VCC = 15V, VSENSE = 26mV to 380mV, AV = 50V/V Short-Circuit Current ISC+, ISC– Reverse VS Supply VO(MIN) 36 150 50 V kHz kHz 15 µs 4.5 10 60 170 µA µA l 0.03 0.02 0.05 0.05 V/µs V/µs 8 15 mA IS(TOTAL) = –200µA, VCC = Open l 50 60 V Minimum Output Voltage VSENSE = 0V, No Load VSENSE = VS+ – VS– = –100mV, AV = 50V/V, No Load l 15 15 35 25 mV mV VO(MAX) Output High (Referred to VCC) AV = 50V/V, VSENSE = 100mV, IL = 0 VSENSE = 100mV, IL = 100µA VSENSE = 100mV, IL = 500µA VSENSE = 100mV, IL = 1mA l l l l 75 85 125 175 140 160 250 400 mV mV mV mV IS+, IS– (Off) Sense Input Current (Power Down) VCC = 0V, VS = 48V, VSENSE = 0V l 0.001 1 µA ISC 6100fd For more information www.linear.com/LT6100 5 LT6100 ELECTRICAL CHARACTERISTICS Note 5: The LT6100C is guaranteed to meet specified performance from 0°C to 70°C. The LT6100C is designed, characterized and expected to meet specified performance from –40°C to 85°C but is not tested or QA sampled at these temperatures. The LT6100I is guaranteed to meet specified performance from –40°C to 85°C. The LT6100H is guaranteed to meet specified performance from –40°C to 125°C. Note 6: This parameter is not 100% tested. Note 7: Gain error for AV = 12.5, 25V/V is guaranteed by the other gain error tests. Note 8: Slew rate is measured on the output between 3.5V and 13.5V. Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: ESD (Electrostatic Discharge) sensitive devices. Extensive use of ESD protection devices are used internal to the LT6100, however, high electrostatic discharge can damage or degrade the device. Use proper ESD handling precautions. Note 3: A heat sink may be required to keep the junction temperature below absolute maximum ratings. Note 4: The LT6100C/LT6100I are guaranteed functional over the operating temperature range of –40°C to 85°C. The LT6100H is guaranteed functional over the operating temperature range of –40°C to 125°C. TYPICAL PERFORMANCE CHARACTERISTICS 9 TYPICAL UNITS VS = 6.4V VCC = 5V 200 100 0 –100 –200 TA = –40°C 0.5 TA = 25°C 0 –0.5 TA = 125°C –1.0 TA = 85°C –1.5 –2.0 –2.5 –300 –3.0 – 400 –40 –25 –10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) –3.5 0 OUTPUT VOLTAGE (V) 1.4 10 40 30 20 VS+ INPUT VOLTAGE (V) 1.2 1.0 0.8 TA = –40°C VS = 4.4V 0.6 0.4 –90 –30 30 90 SENSE VOLTAGE (VS+ – VS–)(mV) 150 6100 G03 TA = –40°C 200 VSENSE = 100mV VS+ = 48V 150 100 0 50 TA = 125°C 0 5 10 15 20 25 30 VCC SUPPLY VOLTAGE (V) Gain vs Temperature TA = –40°C VS > 6.6V 50.04 50.02 2.5 TA = –40°C VS = 6.4V 2.0 1.5 50.00 7 TYPICAL UNITS VSENSE = 50mV TO 80mV VS+ = 6.4V TO 48V VCC = 5V AV = 50V/V 49.98 49.96 49.94 1.0 0 40 35 6100 G02 50.06 49.92 0.5 0.2 0 –150 VS+ = 6.4V TO 48V VCC = 5V TA = –40°C TO 125°C 3.0 TA = –40°C VS > 4.6V TA = 25°C 250 Output Voltage vs Sense Voltage 3.5 OUTPUT VOLTAGE (V) 1.6 TA = 85°C 300 6100 G01 Output Voltage vs Sense Voltage VS+ = 4.4V TO 48V VCC = 3V AV = 10V/V TA = –40°C TO 125°C Input Offset Voltage vs VCC Supply Voltage 50 6100 G21 1.8 350 VSENSE = 100mV VCC = 3V 1.0 GAIN (V/V) INPUT OFFSET VOLTAGE (µV) 300 1.5 INPUT OFFSET VOLTAGE (mV) 400 Input Offset Voltage vs VS+ Input Voltage INPUT OFFSET VOLTAGE (µV) Input Offset Voltage vs Temperature 49.90 0 300 180 240 120 60 SENSE VOLTAGE (VS+ – VS–) (mV) 6100 G04 49.88 –40 –25 –10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) 6100 G05 6100fd 6 For more information www.linear.com/LT6100 LT6100 TYPICAL PERFORMANCE CHARACTERISTICS VS+ = 4.4V TO 48V VCC = 3V 10 8 TA = 125°C 6 TA = 85°C 4 TA = 25°C TA = –40°C 2 0 –110 35 POSITIVE SENSE INPUT CURRENT (µA) NEGATIVE SENSE INPUT CURRENT (µA) 12 Positive Sense Input Current vs Sense Voltage 350 VS+ = 4.4V TO 48V VCC = 3V 30 TA = 125°C 25 TA = 85°C 20 TA = 25°C 15 TA = –40°C 10 5 0 –5 30 70 110 –70 –30 SENSE VOLTAGE (VS+ – VS–) (mV) –110 10k TA = 85°C 120 TA = 25°C 100 TA = –40°C 80 60 40 1k 0 40 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 LOAD CURRENT (mA) G2 = 2V/V 10 AV = 10 20 G2 = 5V/V VS = 12.1V VCC = 10V AV = 50 30 100 10 0 –10 –20 G2 = 1V/V –30 1 –40 0 10 30 40 20 TOTAL VS INPUT VOLTAGE (V) 0.1 50 10k 1k 100k 150 60 VS = 10V VSENSE = 100mV VCC = 5V 70 50 30 20 10 100 1k 10k FREQUENCY (Hz) 100k 1M 6100 G11 0 90 40 –10 0.1 10M Gain Error vs VSENSE GAIN ERROR (%) VCC PSRR (dB) 80 1M 1 110 100 10k 100k FREQUENCY (Hz) 6100 G10 VCC PSRR vs Frequency 130 120 10 1k 6100 G23 VS = 6.4V VCC = 5V 140 –50 100 1M FREQUENCY (Hz) CMRR vs Frequency CMRR (dB) TA = –40°C 50 Gain vs Frequency VS+, VS– = 6.5V VCC = 5V VEE = –5V FIL = 0V 6100 G09 0 TA = 25°C 100 50 20 0 150 6100 G08 GAIN (dB) OUTPUT IMPEDANCE (Ω) VCC SUPPLY CURRENT (µA) TA = 125°C TA = 85°C 200 Op Amp Output Impedance vs Frequency VSENSE = 0V 180 VCC = 3V 140 250 TA = 125°C 6100 G07 VCC Supply Current vs VS Input Voltage 160 VS+ = 6.4V VCC = 5V VSENSE = 150mV AV = 50V/V 300 0 110 –70 –30 30 70 SENSE VOLTAGE (VS+ – VS–) (mV) 6100 G06 200 Output Positive Swing vs Load Current OUTPUT POSITIVE SWING (mV) Negative Sense Input Current vs Sense Voltage –1 –2 1 10 100 1k 10k 100k FREQUENCY (Hz) 1M 6100 G12 –3 VS+ = 6.4V VCC = 5V AV = 10V/V TA = 25°C 0 50 100 150 200 VSENSE (mV) 250 300 6100 G24 6100fd For more information www.linear.com/LT6100 7 LT6100 TYPICAL PERFORMANCE CHARACTERISTICS TOTAL INPUT CURRENT (IS+ + IS–) (nA) 10 Sense Input Current (VCC Powered Down) vs VS+ Step Response at VSENSE = 0V to 130mV VS+ = VS– 10V 10V TA = 125°C 1 TA = 85°C VOUT 500mV/DIV VOUT 2V/DIV 0V 0V TA = 25°C 0.01 VS+ = 10V AV = 10V/V CL = 0pF TA = –40°C 0 10 20 30 VS+ (V) V– 100mV/DIV V– 50mV/DIV 0.1 0.001 Step Response at VSENSE = 0V to 130mV 40 50 6100 G13 50µs/DIV VS+ = 10V AV = 50V/V CL = 0pF 0.2ms/DIV 6100 G14 6100 G25 Step Response at VSENSE = 0V to 10mV Step Response at VSENSE = 0V to 10mV Step Response at VSENSE = 0V to 130mV 10V 10V V– 20mV/DIV 10V V– 20mV/DIV VOUT 50mV/DIV 0V VOUT 200mV/DIV V– 50mV/DIV VOUT 500mV/DIV 0V 0V VS+ = 10V AV = 10V/V COUT = 0pF 50µs/DIV 6100 G15 VS+ = 10V AV = 50V/V CL = 0pF 6100 G16 50µs/DIV Step Response at VSENSE = 0V to 130mV VS+ = 10V AV = 10V/V COUT = 1000pF 50µs/DIV 6100 G17 Step Response at VSENSE = 0V to 10mV 10V 10V V– 20mV/DIV V– 100mV/DIV VOUT 2V/DIV VOUT 50mV/DIV 0V 0V VS+ = 10V AV = 50V/V CL = 1000pF 0.2ms/DIV 6100 G18 VS+ = 10V AV = 10V/V CL = 1000pF 50µs/DIV 6100 G19 6100fd 8 For more information www.linear.com/LT6100 LT6100 TYPICAL PERFORMANCE CHARACTERISTICS Step Response at VSENSE = 0V to 10mV Start-Up Delay 10V V– 20mV/DIV VS+ VOUT 200mV/DIV VOUT 10V 0V 1V 0V 0V VS+ = 10V AV = 50V/V CL = 1000pF 50µs/DIV 6100 G20 VCC = 5V VSENSE = 100mV AV = 10V/V VEE = 0V 20µs/DIV 6100 G22 PIN FUNCTIONS VS– (Pin 1): Negative Sense Input Terminal. Negative sense voltage input will remain functional for voltages up to 48V. VS– is connected to an internal gain-setting resistor RG1 = 5k. VCC (Pin 2): Supply Voltage Input. This power supply pin supplies current to both current sense amplifier and op amp. FIL (Pin 3): Filter Pin. Connects to an external capacitor to roll off differential noise of the system. Pole frequency f–3dB = 1/(2πRFILC), RFIL = RE + RO = 60k. VEE (Pin 4): Negative Supply or Ground for Single Supply Operation. A2 (Pin 6): Gain Select Pin. Refer to Table 1. A4 (Pin 7): Gain Select Pin. When Pin 7 is shorted to VEE, the total gain is 40V/V. When both Pin 6 and Pin 7 are shorted to VEE, the total gain is 50V/V. When both Pin 6 and Pin 7 are opened, the total gain is 10V/V. VS+ (Pin 8): Positive Sense Input Terminal. Connecting a supply to VS+ and a load to VS– will allow the LT6100 to monitor the current through RSENSE, refer to Figure 1. VS+ is connected to an internal gain setting resistor RG2 = 5k. VS+ remains functional for voltages up to 48V. VOUT (Pin 5): Voltage Output Proportional to the Magnitude of the Current Flowing Through RSENSE: VOUT = AV • (VSENSE ± VOS) VOS is the input offset voltage. AV is the total gain of the LT6100. 6100fd For more information www.linear.com/LT6100 9 LT6100 FUNCTIONAL DIAGRAM RSENSE LOAD 1 VIN (VCC + 1.4V) TO 48V 8 VS– RG1 5k VS+ RG2 5k + – R 25k A1 VCC 2.7V TO 36V – 2 VO1 Q1 RE 10k + RO 50k R VEE 4 FIL 3 VOUT 5 R/3 A2 6 A2 A4 7 6100 F01 Figure 1. Functional Diagram 6100fd 10 For more information www.linear.com/LT6100 LT6100 APPLICATIONS INFORMATION The LT6100 high side current sense amplifier (Figure 1) provides accurate unidirectional monitoring of current through a user-selected sense resistor. The LT6100 features a fully specified 4.1V to 48V input common mode range. A high PSRR VCC supply (2.7V to 36V) powers the current sense amplifier and the internal op amp circuitry. The input sense voltage is level shifted from the positive sense power supply to the ground reference and amplified by a user-selected gain to the output. The buffered output voltage is directly proportional to the current flowing through the sense resistor. Theory of Operation (Refer to Figure 1) Current from the source at VS+ flows through RSENSE to the load at VS–, creating a sense voltage, VSENSE. Inputs VS+ and VS– apply the sense voltage to RG2. The opposite ends of resistors RG1 and RG2 are forced to be at equal potentials by the voltage gain of amplifier A1. The current through RG2 is forced to flow through transistor Q1 and is sourced to node VO1. The current from RG2 flowing through resistor RO gives a voltage gain of ten, VO1/VSENSE = RO/ RG2 = 10V/V. The sense amplifier output at VO1 is amplified again by amplifier A2. The inputs of amplifier A2 can operate to ground which ensures that small sense voltage signals are detected. Amplifier A2 can be programmed to different gains via Pin 6 and Pin 7. Thus, the total gain of the system becomes AV = 10 • A2 and VOUT = VSENSE • AV . Gain Setting The LT6100 gain is set by strapping (or floating) the two gain pins (see Table 1). This feature allows the user to “zoom in” by increasing the gain for accurate measurement of low currents. Table 1. Gain Set with Pin 6 and Pin 7 A2 (PIN 6) A4 (PIN 7) G2 AV Open Open 1 10 VEE Out 1.25 12.5 VEE Open 2 20 Out VEE 2.5 25 Open VEE 4 40 VEE VEE 5 50 Selection of External Current Sense Resistor External RSENSE resistor selection is a delicate trade-off between power dissipation in the resistor and current measurement accuracy. The maximum sense voltage may be as large as ±300mV to get maximum dynamic range. For high current applications, the user may want to minimize the sense voltage to minimize the power dissipation in the sense resistor. The LT6100’s low input offset voltage of 80µV allows for high resolution of low sense voltages. This allows limiting the maximum sense voltage while still providing high resolution current monitoring. Kelvin connection of the LT6100’s VS+ and VS– inputs to the sense resistor should be used to provide the highest accuracy in high current applications. Solder connections and PC board interconnect resistance (approximately 0.5mΩ per square) can be a large error in high current systems. A 5A application might choose a 20mΩ sense resistor to give a 100mV full-scale input to the LT6100. Input offset voltage will limit resolution to 4mA. Neglecting contact resistance at solder joints, even one square of PC board copper at each resistor end will cause an error of 5%. This error will grow proportionately higher as monitored current levels rise. AV = 10V/V • G2, G2 is the gain of op amp A2. 6100fd For more information www.linear.com/LT6100 11 LT6100 APPLICATIONS INFORMATION The LT6100 provides signal filtering via pin FIL that is internally connected to the resistors RE and RO. This pin may be used to filter the input signal entering the LT6100’s internal op amp, and should be used when fast ripple current or transients flow through the sense resistor. High frequency signals above the 300kHz bandwidth of the LT6100’s internal amplifier will cause errors. A capacitor connected between FIL and VEE creates a single pole low pass filter with corner frequency: f–3dB = 1/(2πRFILC) where RFIL = 60k. A 220pF capacitor creates a pole at 12kHz, a good choice for many applications. Output Signal Range The LT6100’s output signal is developed by current through RG2 into output resistor RO. The current is VSENSE/RG2. The sense amplifier output, VO1, is buffered by the internal op amp so that connecting the output pins to other systems will preserve signal accuracy. For zero VSENSE, internal circuit saturation with loss of accuracy occurs at the minimum VOUT swing, 15mV above VEE. VOUT may swing positive to within 75mV of VCC or a maximum of 36V, a limit set by internal junction breakdown. Within these constraints, 1.5 Sense Input Signal Range The LT6100 has high CMRR over the wide input voltage range of 4.1V to 48V. The minimum operation voltage of the sense amplifier input is 1.4V above VCC. The output remains accurate even when the sense inputs are driven to 48V. Figure 2 shows that VOS changes very slightly over a wide input range. Furthermore, the sense inputs VS+ and VS– can collapse to zero volts without incurring any damage to the device. The LT6100 can handle differential sense voltages up to the voltage of the sense inputs supplies. For example, VS+ = 48V and VS– = 0V can be a valid condition in a current monitoring application (Figure 3) when an overload protection fuse is blown and VS– voltage collapses to ground. Under this condition, the output of the LT6100 goes to the positive rail, VOH. There is no phase inversion to cause an erroneous output signal. For the opposite case when VS+ collapse to ground with VS– held up at some higher voltage potential, the output will sit at VOL. If both inputs fall below the minimum CM voltage, VCC + 1.4V, the output is indeterminate but the LT6100 will not be damaged. TO LOAD VSENSE = 100mV VCC = 3V TA = 25°C 1.0 0.5 RSENSE FUSE 0 –0.5 + –1.0 –1.5 2 5V C2 0.1µF 3 –2.0 1 8 VS– VS+ VCC C1 0.1µF A4 – INPUT OFFSET VOLTAGE (mV) an amplified, level shifted representation of the RSENSE voltage is developed at VOUT . The output is well behaved driving capacitive loads to 1000pF. DC SOURCE 7 + Noise Filtering A2 FIL 6 –2.5 –3.0 –3.5 4 0 10 40 30 20 VS INPUT VOLTAGE (V) 50 VEE OUT 5 OUTPUT LT6100 6100 F03 6100 F02 Figure 2. VOS vs VS Input Voltage Figure 3. Current Monitoring of a Fuse Protected Circuit 6100fd 12 For more information www.linear.com/LT6100 LT6100 APPLICATIONS INFORMATION Low Sense Voltage Operation Figure 4 shows the simplest circuit configuration in which the LT6100 may be used. While VOUT (output voltage) increases with positive sense current, at VSENSE = 0V, the LT6100’s buffered output can only swing as low as 1.6 TO LOAD 8 VS– VS+ VCC C1 0.1µF A4 + A2 FIL VS = 4.4V TO 48V VCC = 3V AV = 10V/V TA = 25°C 1.4 5V 7 6 OUTPUT VOLTAGE (V) 3 1 – C2 0.1µF 3V RSENSE + + 2 VOL = 15mV. The accuracy at small sense voltages can be improved by selecting higher gain. When gain of 50V/V is selected, as shown in Figure 7, VOUT leaves the clipped region for a positive VSENSE greater than 1mV compared to 2.5mV for gain of 10V/V (see Figure 6). 1.2 1.0 0.8 0.6 0.4 0.2 4 OUT 5 VEE 0 OUTPUT LT6100 0 6100 F04 30 60 120 90 SENSE VOLTAGE (VS+ – VS–) (mV) 150 6100 F05 Figure 4. LT6100 Load Current Monitor 0.40 0.30 VS = 4.4V TO 48V VCC = 3V AV = 50V/V TA = 25°C 1.6 1.4 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1.8 VS = 4.4V TO 48V VCC = 3V AV = 10V/V TA = 25°C 0.35 0.25 0.20 0.15 0.10 1.2 1.0 0.8 0.6 0.4 0.05 0 Figure 5. Output Voltage vs VSENSE 0.2 0 5 10 20 25 15 SENSE VOLTAGE (VS+ – VS–) (mV) 30 0 0 6100 F06 Figure 6. Expanded View of Output Voltage vs VSENSE, AV = 10V/V 10 5 15 20 25 SENSE VOLTAGE (VS+ – VS–) (mV) 30 6100 F07 Figure 7. Expanded View of Output Voltage vs VSENSE, AV = 50V/V 6100fd For more information www.linear.com/LT6100 13 LT6100 APPLICATIONS INFORMATION Power Down While Connected to a Battery its inputs remain high impedance (see Figure 8). This is due to the implementation of Linear Technology’s OverThe-Top® input topology at its front end. When powered down, the LT6100 inputs draw less than 1µA of current. Another unique benefit of the LT6100 is that you can leave it connected to a battery even when it is denied power. When the LT6100 loses power or is intentionally powered down, ISENSE RSENSE TO LOAD – LT6100 VS BATTERY 4.1V TO 48V – + POWER DOWN OK VCC 3V 0V INPUTS REMAIN Hi-Z + VS+ VCC FIL VOUT VEE A2 A4 6100 F08 Figure 8. Input Remains Hi-Z when LT6100 is Powered Down TYPICAL APPLICATION Micro-Hotplate Voltage and Current Monitor Adjust Gain Dynamically for Enhanced Range VS+ VS 10Ω 1% VS– IHOTPLATE – + 5V FROM SOURCE – VCC 5V FIL A2 2N7002 A4 MICRO-HOTPLATE BOSTON MICROSYSTEMS MHP100S-005 6100 TA05 0V (GAIN = 10) VCC VEE VOUT VEE 5V 5V (GAIN = 50) VDR– VS+ + – LT6100 VDR+ ISENSE RSENSE TO LOAD LT6100 A2 A4 CURRENT MONITOR VOUT = 500mV/mA 5V M9 M3 M1 P1 P3 P9 LT1991 VOLTAGE MONITOR V + – VDR– VOUT = DR 10 6100 TA06 www.bostonmicrosystems.com 6100fd 14 For more information www.linear.com/LT6100 LT6100 PACKAGE DESCRIPTION Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. DD Package 8-Lead Plastic DFN (3mm × 3mm) (Reference LTC DWG # 05-08-1698 Rev C) 0.70 ±0.05 3.5 ±0.05 1.65 ±0.05 2.10 ±0.05 (2 SIDES) PACKAGE OUTLINE 0.25 ±0.05 0.50 BSC 2.38 ±0.05 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED PIN 1 TOP MARK (NOTE 6) 0.200 REF 3.00 ±0.10 (4 SIDES) R = 0.125 TYP 5 0.40 ±0.10 8 1.65 ±0.10 (2 SIDES) 0.75 ±0.05 4 0.25 ±0.05 1 (DD8) DFN 0509 REV C 0.50 BSC 2.38 ±0.10 0.00 – 0.05 BOTTOM VIEW—EXPOSED PAD NOTE: 1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-1) 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON TOP AND BOTTOM OF PACKAGE 6100fd For more information www.linear.com/LT6100 15 LT6100 PACKAGE DESCRIPTION Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. MS8 Package 8-Lead Plastic MSOP (Reference LTC DWG # 05-08-1660 Rev G) 0.889 ±0.127 (.035 ±.005) 5.10 (.201) MIN 3.20 – 3.45 (.126 – .136) 3.00 ±0.102 (.118 ±.004) (NOTE 3) 0.65 (.0256) BSC 0.42 ± 0.038 (.0165 ±.0015) TYP 8 7 6 5 0.52 (.0205) REF RECOMMENDED SOLDER PAD LAYOUT 0.254 (.010) 3.00 ±0.102 (.118 ±.004) (NOTE 4) 4.90 ±0.152 (.193 ±.006) DETAIL “A” 0° – 6° TYP GAUGE PLANE 0.53 ±0.152 (.021 ±.006) DETAIL “A” 1 2 3 4 1.10 (.043) MAX 0.86 (.034) REF 0.18 (.007) SEATING PLANE 0.22 – 0.38 (.009 – .015) TYP 0.65 (.0256) BSC 0.1016 ±0.0508 (.004 ±.002) MSOP (MS8) 0213 REV G NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX 6100fd 16 For more information www.linear.com/LT6100 LT6100 REVISION HISTORY (Revision history begins at Rev C) REV DATE DESCRIPTION C 11/12 Corrected value in Output Signal Range section. PAGE NUMBER 11 D 07/14 Corrected part numbers in Order Information 2 Corrected Specified Temperature Range for LT6100C 2 Updated format of Order Information 2 Added web links All 6100fd Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. For more information www.linear.com/LT6100 17 LT6100 TYPICAL APPLICATIONS 800mA/1A White LED Current Regulator D2 LED L1 3µH VIN D1 B130 0.030Ω FB SHDN GND 124k VC + – 22µF 16V CER 1210 0.1µF 8.2k VEE 6100 TA02 ISENSE VSUPPLY 6.4V TO 48V VS– LOAD LT6100 – + 3V Gain of 50 Current Sense RSENSE VS+ VCC 5V FIL RSENSE VS+ VS– LOAD VCC FIL VOUT 20 • RSENSE • ISENSE 1000pF VEE A2 + LT6100 A4 OPEN: 1A CLOSED: 800mA Filtered Gain of 20 Current Sense ISENSE VCC 4.99k D1: DIODES INC. D2: LUMILEDS LXML-PW09 WHITE EMITTER L1: SUMIDA CDRH6D28-3R0 VSUPPLY 4.4V TO 48V VS– VOUT MMBT2222 4.7µF 6.3V CER LT6100 VSW LT3436 LED ON VS+ – VIN 3.3V TO 4.2V SINGLE Li-Ion LED CURRENT WARNING! VERY BRIGHT DO NOT OBSERVE DIRECTLY A2 A4 VEE 6100 TA03 A2 VOUT 50 • RSENSE • ISENSE A4 6100 TA04 –3dB AT 2.6kHz RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC 1043 Dual Precision Instrumentation Switched Capacitor Building Block 120dB CMRR, 3V to 18V Operation LT1490/LT1491 Dual and Quad Micropower Rail-to-Rail Input and Output Op Amps 50µA Amplifier, 2.7V to 40V Operation, Over-The-Top Inputs LT1620/LT1621 Rail-to-Rail Current Sense Amplifiers Accurate Output Current Programming, Battery Charging to 32V LT1787 Precision Bidirectional, High Side Current Sense Amplifier 75µV VOS, 60V, 60µA Operation ® LTC6101/LTC6101HV High Voltage, High Side, Precision Current Sense Amplifiers 4V to 60V/5V to 100V, Gain Configurable, SOT-23 6100fd 18 Linear Technology Corporation LT 0714 REV D • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● For more information www.linear.com/LT6100 www.linear.com/LT6100 LINEAR TECHNOLOGY CORPORATION 2005