LT1990 250V Input Range G = 1, 10, Micropower, Difference Amplifier DESCRIPTIO U FEATURES Pin Selectable Gain of 1 or 10 High Common Mode Voltage Range: 85V Window (VS = 5V, 0V) 250V (VS = 15V) Common Mode Rejection Ratio: 70dB Min Input Protection to 350V Gain Error: 0.28% Max PSRR: 82dB Min High Input Impedance: 2M Differential, 500k Common Mode Micropower: 120A Max Supply Current Wide Supply Range: 2.7V to 36V -3dB Bandwidth: 100kHz Rail-to-Rail Output 8-Pin SO Package The LT(R)1990 is a micropower precision difference amplifier with a very high common mode input voltage range. It has pin selectable gains of 1 or 10. The LT1990 operates over a 250V common mode voltage range on a 15V supply. The inputs are fault protected from common mode voltage transients up to 350V and differential voltages up to 500V. The LT1990 is ideally suited for both high side and low side current or voltage monitoring. On a single 5V supply, the LT1990 has an adjustable 85V input range, 70dB min CMRR and draws less than 120A supply current. The rail-to-rail output maximizes the dynamic range, especially important for single supplies as low as 2.7V. The LT1990 is specified for single 3V, 5V and 15V supplies over both commercial and industrial temperature ranges. The LT1990 is available in the 8-pin SO package. U APPLICATIO S Battery Cell Voltage Monitoring High Voltage Current Sensing Signal Acquisition in Noisy Environments Input Protection Fault Protected Front Ends Level Sensing Isolation , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. U TYPICAL APPLICATIO Full-Bridge Load Current Monitor +VSOURCE 5V LT1990 900k 10k 8 7 - + 2 1M 3 1M 100k - RS 6 VOUT + VREF = 1.5V IL 4 OUT IN LT6650 GND FB -12V VCM 73V VOUT = VREF (10 * IL * RS) 10k 1nF 54.9k 40k 5 900k 40k 100k 20k 1 1990 TA01 1F 1990fb 1 LT1990 U W W W ABSOLUTE AXI U RATI GS U W U PACKAGE/ORDER I FOR ATIO (Notes 1, 2) Total Supply Voltage (V + to V -) ............................... 36V Input Voltage Range Continuous ...................................................... 250V Transient (0.1s) ............................................... 350V Differential ....................................................... 500V Output Short-Circuit Duration (Note 3) ............ Indefinite Operating Temperature Range (Note 4) LT1990C .............................................. -40C to 85C LT1990I ............................................... -40C to 85C LT1990H ........................................... -40C to 125C Specified Temperature Range (Note 5) LT1990C .............................................. -40C to 85C LT1990I ............................................... -40C to 85C LT1990H ........................................... -40C to 125C Junction Temperature ........................................... 150C Storage Temperature Range .................. -65C to 150C Lead Temperature (Soldering, 10 sec.)................. 300C TOP VIEW REF 1 8 GAIN1 -IN 2 7 V+ +IN 3 6 OUT V- 4 5 GAIN2 S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150C, JA = 190C/W ORDER PART NUMBER LT1990CS8 LT1990IS8 LT1990HS8 LT1990ACS8 LT1990AIS8 LT1990AHS8 S8 PART MARKING 1990 1990I 1990H 1990A 1990AI 1990AH Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ Consult LTC Marketing for parts specified with wider operating temperature ranges. 3V/5V ELECTRICAL CHARACTERISTICS VS = 3V, 0V; VS = 5V, 0V; RL = 10k, VCM = VREF = half supply, G = 1, 10, TA = 25C, unless otherwise noted. (Note 6) SYMBOL PARAMETER CONDITIONS G Gain Pins 5 and 8 = Open Pins 5 and 8 = VREF G Gain Error VOUT = 0.5V to (+Vs) -0.75V LT1990, G = 1 LT1990A, G = 1 G = 10, VS = 5V, 0V VS = 5V, 0V; VOUT = 0.5V to 4.25V G=1 G = 10 GNL VCM CMRR Gain Nonlinearity Input Voltage Range Common Mode Rejection Ratio RTI (Referred to Input) MIN TYP MAX UNITS 0.4 0.07 0.2 0.6 0.28 0.8 % % % 0.001 0.01 0.005 % % 25 80 47 V V V 1 10 Guaranteed by CMRR VS = 3V, 0V; VREF = 1.25V VS = 5V, 0V; VREF = 1.25V VS = 5V, 0V; VREF = 2.5V -5 -5 -38 VS = 3V, 0V (Note 7) VCM = -5V to 25V, VREF = 1.25V LT1990 LT1990A 60 70 68 75 dB dB VS = 5V, 0V VCM = -5V to 80V, VREF = 1.25V LT1990 LT1990A 60 70 68 75 dB dB VS = 5V, 0V (Note 7) VCM = -38V to 47V, VREF = 2.5V LT1990 LT1990A 60 70 68 75 dB dB 1990fb 2 LT1990 3V/5V ELECTRICAL CHARACTERISTICS VS = 3V, 0V; VS = 5V, 0V; RL = 10k, VCM = VREF = half supply, G = 1, 10, TA = 25C, unless otherwise noted. (Note 6) SYMBOL PARAMETER CONDITIONS VOS Offset Voltage, RTI en MIN TYP MAX G = 1, 10 0.8 3 Input Noise Voltage, RTI fO = 0.1Hz to 10Hz 22 VP-P Noise Voltage Density, RTI fO = 1kHz 1 V/Hz RIN Input Resistance Differential Common Mode PSRR Power Supply Rejection Ratio, RTI VS = 2.7V to 12.7V, VCM = VREF = 1.25V Minimum Supply Voltage Guaranteed by PSRR 2.4 2.7 80 UNITS mV 2 0.5 M M 92 dB V IS Supply Current (Note 8) 105 120 A VOL Output Voltage Swing LOW -IN = V+, +IN = Half Supply (Note 8) 30 50 mV VOH Output Voltage Swing HIGH -IN = 0V, +IN = Half Supply VS = 3V, 0V, Below V+ VS = 5V, 0V, Below V+ 100 120 150 175 mV mV ISC Output Short-Circuit Current Short to GND (Note 9) Short to V+ (Note 9) BW Bandwidth (-3dB) SR AVREF 4 13 8 20 mA mA G=1 G = 10 100 6.5 kHz kHz Slew Rate G = 1, VS = 5V, 0V, VOUT = 0.5V to 4.5V 0.5 V/s Settling Time to 0.01% 4V Step, G = 1, VS = 5V, 0V 45 s Reference Gain to Output G=1 G = 10 1 0.0007 1 0.007 The denotes the specifications which apply over the temperature range of 0C TA 70C. VS = 3V, 0V; VS = 5V, 0V; RL = 10k, VCM = VREF = half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6) SYMBOL PARAMETER CONDITIONS G Gain Error VOUT = 0.5V to (+VS) - 0.75V LT1990, G = 1 LT1990A, G = 1 G = 10 LT1990C/LT1990I MIN TYP MAX UNITS 0.65 0.33 0.90 % % % G/T Gain vs Temperature G = 1 (Note 10) G = 10 (Note 10) VCM Input Voltage Range Guaranteed by CMRR VS = 3V, 0V, VREF = 1.25V VS = 5V, 0V, VREF = 1.25V VS = 5V, 0V, VREF = 2.5V -5 -5 -37 VS = 3V, 0V (Note 7) VCM = -5V to 25V, VREF = 1.25V LT1990 LT1990A 58 68 dB dB VS = 5V, 0V VCM = -5V to 80V, VREF = 1.25V LT1990 LT1990A 58 68 dB dB VS = 5V, 0V (Note 7) VCM = -38V to 47V, VREF = 2.5V LT1990 LT1990A 58 68 dB dB CMRR Common Mode Rejection Ratio, RTI 2 7 10 20 ppm/C ppm/C 25 80 48 V V V 1990fb 3 LT1990 3V/5V ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the temperature range of 0C TA 70C. VS = 3V, 0V; VS = 5V, 0V; RL = 10k, VCM = VREF = half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6) LT1990C/LT1990I MIN TYP MAX SYMBOL PARAMETER CONDITIONS VOS Input Offset Voltage, RTI VS = 3V, 0V G = 1, 10 4.1 mV VS = 5V, 0V G = 1, 10 4.1 mV 22 V/C VOS/T Input Offset Voltage Drift, RTI (Note 10) 5 VOSH Input Offset Voltage Hysteresis, RTI (Note 11) 230 PSRR Power Supply Rejection Ratio, RTI VS = 2.7V to 12.7V VCM = VREF = 1.25V G = 1, 10 Guaranteed by PSRR 2.7 Minimum Supply Voltage UNITS V 78 dB V IS Supply Current (Note 8) 150 A VOL Output Voltage Swing LOW -IN = V+, +IN = Half Supply (Note 8) 60 mV VOH Output Voltage Swing HIGH -IN = 0V, +IN = Half Supply VS = 3V, 0V, Below V+ VS = 5V, 0V, Below V+ 180 205 mV mV Short to GND (Note 9) Short to V+ (Note 9) ISC Output Short-Circuit Current 3 11 mA mA The denotes the specifications which apply over the temperature range of -40C TA 85C. VS = 3V, 0V; VS = 5V, 0V; RL = 10k, VCM = VREF = half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6) SYMBOL PARAMETER CONDITIONS G Gain Error VOUT = 0.5V to (+VS) - 0.75V LT1990, G = 1 LT1990A, G = 1 G = 10 LT1990C/LT1990I MIN TYP MAX UNITS 0.67 0.35 0.95 % % % G/T Gain vs Temperature G = 1 (Note 10) G = 10 (Note 10) VCM Input Voltage Range Guaranteed by CMRR VS = 3V, 0V, VREF = 1.25V VS = 5V, 0V, VREF = 1.25V VS = 5V, 0V, VREF = 2.5V -5 -5 -37 VS = 3V, 0V (Note 7) VCM = -5V to 25V, VREF = 1.25V LT1990 LT1990A 57 67 dB dB VS = 5V, 0V VCM = -5V to 80V, VREF = 1.25V LT1990 LT1990A 57 67 dB dB VS = 5V, 0V (Note 7) VCM = -38V to 47V, VREF = 2.5V LT1990 LT1990A 57 67 dB dB CMRR Common Mode Rejection Ratio, RTI 2 7 10 20 ppm/C ppm/C 25 80 48 V V V 1990fb 4 LT1990 3V/5V ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the temperature range of -40C TA 85C. VS = 3V, 0V; VS = 5V, 0V; RL = 10k, VCM = VREF = half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6) LT1990C/LT1990I MIN TYP MAX SYMBOL PARAMETER CONDITIONS UNITS VOS Input Offset Voltage, RTI VS = 3V, 0V G = 1, 10 4.5 mV VS = 5V, 0V G = 1, 10 4.5 mV 22 V/C VOS/T Input Offset Voltage Drift, RTI (Note 10) 5 VOSH Input Offset Voltage Hysteresis, RTI (Note 11) 230 PSRR Power Supply Rejection Ratio, RTI VS = 2.7V to 12.7V VCM = VREF = 1.25V Minimum Supply Voltage Guaranteed by PSRR 2.7 V Supply Current (Note 8) 170 A VOL Output Voltage Swing LOW -IN = V+, +IN = Half Supply (Note 8) 70 mV VOH Output Voltage Swing HIGH -IN = 0V, +IN = Half Supply VS = 3V, 0V, Below V+ VS = 5V, 0V, Below V+ 200 275 mV mV Short to GND (Note 9) Short to V+ (Note 9) IS ISC Output Short-Circuit Current V 76 dB 2 8 mA mA 3V/5V ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the temperature range of -40C TA 125C. VS = 3V, 0V; VS = 5V, 0V; RL = 10k, VCM = VREF = half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6) SYMBOL PARAMETER CONDITIONS MIN G Gain Error VOUT = 0.5V to (+VS) - 0.75V LT1990, G = 1 LT1990A, G = 1 G = 10 LT1990H TYP MAX UNITS 0.69 0.37 0.97 % % % G/T Gain vs Temperature G = 1 (Note 10) G = 10 (Note 10) VCM Input Voltage Range Guaranteed by CMRR VS = 3V, 0V, VREF = 1.25V VS = 5V, 0V, VREF = 1.25V VS = 5V, 0V, VREF = 2.5V -5 -5 -37 VS = 3V, 0V (Note 7) VCM = -5V to 25V, VREF = 1.25V LT1990 LT1990A 56 66 dB dB VS = 5V, 0V VCM = -5V to 80V, VREF = 1.25V LT1990 LT1990A 56 66 dB dB VS = 5V, 0V (Note 7) VCM = -38V to 47V, VREF = 2.5V LT1990 LT1990A 56 66 dB dB CMRR Common Mode Rejection Ratio, RTI 2 7 10 20 ppm/C ppm/C 25 80 48 V V V 1990fb 5 LT1990 3V/5V ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the temperature range of -40C TA 125C. VS = 3V, 0V; VS = 5V, 0V; RL = 10k, VCM = VREF = half supply, G = 1, 10, unless otherwise noted. (Notes 4, 6) SYMBOL PARAMETER CONDITIONS MIN VOS Input Offset Voltage, RTI VS = 3V, 0V G = 1, 10 VS = 5V, 0V G = 1, 10 LT1990H TYP MAX 5.2 mV 5.2 mV 22 V/C VOS/T Input Offset Voltage Drift, RTI (Note 10) 5 VOSH Input Offset Voltage Hysteresis, RTI (Note 11) 250 PSRR Power Supply Rejection Ratio, RTI VS = 2.7V to 12.7V VCM = VREF = 1.25V Guaranteed by PSRR 2.7 Minimum Supply Voltage UNITS V 75 dB V IS Supply Current (Note 8) 200 A VOL Output Voltage Swing LOW -IN = V+, +IN = Half Supply (Note 8) 80 mV VOH Output Voltage Swing HIGH -IN = 0V, +IN = Half Supply VS = 3V, 0V, Below V+ VS = 5V, 0V, Below V+ 230 275 mV mV Short to GND (Note 9) Short to V+ (Note 9) ISC Output Short-Circuit Current 1 5 mA mA 15V ELECTRICAL CHARACTERISTICS VS = 15V, RL = 10k, VCM = VREF = 0V, G = 1, 10, TA = 25C, unless otherwise noted. (Note 6) SYMBOL PARAMETER CONDITIONS G Gain Pins 5 and 8 = Open Pins 5 and 8 = VREF G Gain Error VOUT = 10V LT1990, G = 1 LT1990A, G = 1 G = 10 GNL Gain Nonlinearity MIN TYP MAX UNITS 0.6 0.28 0.8 % % % 0.0008 0.002 0.005 0.02 % % 1 10 0.4 0.07 0.2 VOUT = 10V G=1 G = 10 VCM Input Voltage Range Guaranteed by CMRR -250 CMRR Common Mode Rejection Ratio, RTI VCM = -250V to 250V LT1990 LT1990A 60 70 250 68 75 V dB dB VOS Offset Voltage, RTI G = 1, 10 0.9 en Input Noise Voltage, RTI fO = 0.1Hz to 10Hz 22 VP-P Noise Voltage Density, RTI fO = 1kHz 1 V/Hz RIN Input Resistance Differential Common Mode PSRR Power Supply Rejection Ratio, RTI VS = 1.35V to 18V Minimum Supply Voltage Guaranteed by PSRR IS Supply Current VOUT Output Voltage Swing 82 14.5 5.2 mV 2 0.5 M M 100 dB 1.2 1.35 V 140 180 A 14.79 V 1990fb 6 LT1990 15V ELECTRICAL CHARACTERISTICS VS = 15V, RL = 10k, VCM = VREF = 0V, G = 1, 10, TA = 25C, unless otherwise noted. (Note 6) SYMBOL PARAMETER CONDITIONS ISC Output Short-Circuit Current Short to V- BW Bandwidth SR Slew Rate G = 1, VOUT = 10V Settling Time to 0.01% 10V Step, G = 1 Reference Gain to Output G=1 G = 10 AVREF Short to V+ MIN TYP 6 15 9 22 mA mA 105 7 kHz kHz 0.55 V/s G=1 G = 10 0.3 MAX UNITS s 60 1 0.0007 1 0.007 The denotes the specifications which apply over the temperature range of 0C TA 70C. VS = 15V, RL = 10k, VCM = VREF = 0V, G = 1, 10, unless otherwise noted. (Notes 4, 6) LT1990C/LT1990I MIN TYP MAX UNITS 0.65 0.33 0.9 % % % VOUT = 10V G=1 G = 10 0.0025 0.025 % % Gain vs Temperature G = 1 (Note 10) G = 10 (Note 10) VCM Input Voltage Range Guaranteed by CMRR -250 CMRR Common Mode Rejection Ratio, RTI VCM = -250V to 250V LT1990 LT1990A 59 68 SYMBOL PARAMETER CONDITIONS G Gain Error VOUT = 10V LT1990, G = 1 LT1990A, G = 1 G = 10 GNL G/T Gain Nonlinearity VOS Input Offset Voltage, RTI G = 1, 10 VOS/T Input Offset Voltage Drift, RTI (Note 10) VOSH Input Offset Voltage Hysteresis, RTI (Note 11) PSRR Power Supply Rejection Ratio, RTI VS = 1.35V to 18V Minimum Supply Voltage Guaranteed by PSRR 2 7 10 20 ppm/C ppm/C 250 V dB dB 5 6.2 mV 22 V/C V 250 80 dB 1.35 V 230 A IS Supply Current VOUT Output Voltage Swing 14.4 Short to V+ 5 13 mA mA G = 1, VOUT = 10V 0.25 V/s ISC Output Short-Circuit Current SR Slew Rate Short to V- V 1990fb 7 LT1990 15V ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the temperature range of -40C TA 85C. VS = 15V, RL = 10k, VCM = VREF = 0V, G = 1, 10, unless otherwise noted. (Notes 4, 6) LT1990C/LT1990I MIN TYP MAX UNITS 0.67 0.35 0.95 % % % VOUT = 10V G=1 G = 10 0.003 0.03 % % Gain vs Temperature G = 1 (Note 10) G = 10 (Note 10) VCM Input Voltage Range Guaranteed by CMRR -250 CMRR Common Mode Rejection Ratio, RTI VCM = -250V to 250V LT1990 LT1990A 58 67 SYMBOL PARAMETER CONDITIONS G Gain Error VOUT = 10V LT1990, G = 1 LT1990A, G = 1 G = 10 GNL G/T Gain Nonlinearity VOS Input Offset Voltage, RTI G = 1, 10 VOS/T Input Offset Voltage Drift, RTI (Note 10) VOSH Input Offset Voltage Hysteresis, RTI (Note 11) PSRR Power Supply Rejection Ratio, RTI VS = 1.35V to 18V Minimum Supply Voltage Guaranteed by PSRR 2 7 10 20 ppm/C ppm/C 250 V dB dB 5 6.7 mV 22 V/C V 250 78 dB 1.35 V 280 A IS Supply Current VOUT Output Voltage Swing 14.3 V Short to V+ 3 10 mA mA G = 1, VOUT = 10V 0.2 V/s ISC Output Short-Circuit Current SR Slew Rate Short to V- 15V ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the temperature range of -40C TA 125C. VS = 15V, RL = 10k, VCM = VREF = 0V, G = 1, 10, unless otherwise noted. (Notes 4, 6) LT1990H TYP MAX UNITS 0.69 0.37 0.97 % % % VOUT = 10V G=1 G = 10 0.0035 0.035 % % Gain vs Temperature G = 1 (Note 10) G = 10 (Note 10) VCM Input Voltage Range Guaranteed by CMRR -250 CMRR Common Mode Rejection Ratio, RTI VCM = -250V to 250V LT1990 LT1990A 57 66 SYMBOL PARAMETER CONDITIONS G Gain Error VOUT = 10V LT1990, G = 1 LT1990A, G = 1 G = 10 GNL G/T Gain Nonlinearity MIN VOS Input Offset Voltage, RTI G = 1, 10 VOS/T Input Offset Voltage Drift, RTI (Note 10) 2 7 10 20 ppm/C ppm/C 250 V dB dB 5 7.4 mV 22 V/C 1990fb 8 LT1990 15V ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the temperature range of -40C TA 125C. VS = 15V, RL = 10k, VCM = VREF = 0V, G = 1, 10, unless otherwise noted. (Notes 4, 6) PARAMETER CONDITIONS VOSH Input Offset Voltage Hysteresis, RTI (Note 11) PSRR Power Supply Rejection Ratio, RTI VS = 1.35V to 18V Minimum Supply Voltage Guaranteed by PSRR 1.35 V 330 A IS Supply Current VOUT Output Voltage Swing ISC Output Short-Circuit Current SR Slew Rate MIN LT1990H TYP MAX SYMBOL UNITS V 250 77 dB 14.2 V Short to V+ 1.5 7 mA mA G = 1, VOUT = 10V Short to V - 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 device. Extensive use of ESD protection devices are used internal to the LT1990, 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. Note 4: The LT1990C/LT1990I are guaranteed functional over the operating temperature range of - 40C to 85C. The LT1990H is guaranteed functional over the operating temperature range of -40C to 125C. Note 5: The LT1990C is guaranteed to meet the specified performance from 0C to70C and is designed, characterized and expected to meet specified performance from -40C to 85C but is not tested or QA 0.1 V/s sampled at these temperatures. The LT1990I is guaranteed to meet specified performance from -40C to 85C. The LT1990H is guaranteed to meet specified performance from -40C to 125C. Note 6: G = 10 limits are guaranteed by correlation to G = 1 tests and gain error tests at G = 10. Note 7: Limits are guaranteed by correlation to -5V to 80V CMRR tests. Note 8: VS = 3V limits are guaranteed by correlation to VS = 5V and VS = 15V tests. Note 9: VS = 5V limits are guaranteed by correlation to VS = 3V and VS = 15V tests. Note 10: This parameter is not 100% tested. Note 11: Hysteresis in offset voltage is created by package stress that differs depending on whether the IC was previously at a higher or lower temperature. Offset voltage hysteresis is always measured at 25C, but the IC is cycled to 85C I-grade (70C C-grade or 125C H-grade) or -40C I/H-grade (0C C-grade) before successive measurement. 1990fb 9 LT1990 U W TYPICAL PERFOR A CE CHARACTERISTICS Supply Current vs Supply Voltage 200 TA = 125C 180 TA = 85C 160 TA = 25C 140 TA = -40C 120 TA = -55C 100 80 V + - 0.01 VS = 5V, 0V 60 130 120 110 100 90 80 5 10 15 20 25 30 SUPPLY VOLTAGE (V) 60 -50 40 35 -25 0 25 50 75 TEMPERATURE (C) 100 1990 G01 TA = 125C -1 TA = 25C TA = 25C +1 SINKING (+IN = -2.5V) +0.1 TA = 125C TA = -55C TA = -55C V + -0.01 VS = 2.5V G = 10 -0.1 NO LOAD OUTPUT VOLTAGE WITH RESPECT TO SUPPLY (V) TA = 125C TA = 25C -1 +1 TA = 25C +0.1 TA = -55C TA = 25C +1 TA = 25C 0 0.2 0.4 0.6 0.8 DIFFERENTIAL INPUT VOLTAGE (V) MAXIMUM INPUT VOLTAGE (V) TA = -55C 10 TA = 25C TA = 125C SINK -10 TA = 125C -15 TA = -55C -20 TA = 25C -25 1.0 2 4 8 10 12 6 SUPPLY VOLTAGE (V) 14 16 1990 G07 OUTPUT FULLY SATURATED G = 10 G = 1 2 4 6 8 10 12 SUPPLY VOLTAGE (V) 300 VREF = 4V 150 VREF = 1.25V 100 VREF = 2.5V 50 VREF = 1.25V 0 VREF = 2.5V -50 16 1990 G06 V - = 0V TA = -40C TO 85C 200 14 Input Voltage Range vs Split Supply Voltage VREF = 0V TA = -40C TO 85C 200 100 0 -100 -200 VREF = 4V -100 0 V - +0.01 0 Input Voltage Range vs Single Supply Voltage SOURCE 0 +0.1 G = 10, V+IN = V -/10 G=1 G = 10 OUTPUT FULLY SATURATED 1990 G05 250 -5 V-IN = 0V VREF = 0V NO LOAD TA = 25C G = 1, V+IN = V - TA = -55C V - +0.01 25 5 -0.1 G = 10, V = V+/10 +IN TA = 125C Output Short-Circuit Current vs Supply Voltage 15 G = 1, V+IN = V+ TA = 125C 1990 G04 20 V + -0.01 TA = -55C +0.1 4.0 100 Output Voltage Swing vs Supply Voltage -1 TA = 125C 0.5 1.0 1.5 2.0 2.5 3.0 3.5 DIFFERENTIAL INPUT VOLTAGE (V) 0.01 0.1 1 10 OUTPUT CURRENT (mA) 1990 G03 OUTPUT SWING WITH RESPECT TO SUPPLY (V) VS = 2.5V G=1 -0.1 NO LOAD 0 V - +0.01 0.001 Output Voltage vs Input Voltage, G = 10 V + -0.01 OUTPUT VOLTAGE WITH RESPECT TO SUPPLY (V) SOURCING (+IN = 2.5V) 1990 G02 Output Voltage vs Input Voltage, G = 1 V - +0.01 125 MAXIMUM INPUT VOLTAGE (V) 0 OUTPUT SHORT-CIRCUIT CURRENT (mA) - 0.1 70 40 -30 VS = 2.5V -IN = 0V G=1 TA = -55C 140 SUPPLY CURRENT (A) SUPPLY CURRENT (A) 150 VREF = VOUT = 1.25V V - = 0V OUTPUT VOLTAGE SWING WITH RESPECT TO SUPPLY (V) 220 Output Voltage Swing vs Load Current Supply Current vs Temperature 3 7 9 11 13 5 POSITIVE SUPPLY VOLTAGE (V) 15 1990 G08 -300 1 3 9 7 11 5 SUPPLY VOLTAGE (V) 13 15 1990 G09 1990fb 10 LT1990 U W TYPICAL PERFOR A CE CHARACTERISTICS Common Mode Rejection Ratio vs Frequency Gain vs Frequency 50 VS = 5V, 0V 40 TA = 25C VS = 5V, 0V TA = 25C G = 1 OR 10 REFERRED TO INPUT 90 80 30 70 20 60 10 GAIN (dB) COMMON MODE REJECTION RATIO (dB) 100 50 40 0 G = 10 G=1 -10 -20 30 20 -30 10 -40 0 100 10k 1k FREQUENCY (Hz) -50 100 100k 200k 1k 10k 100k FREQUENCY (Hz) 1M 1990 G10 -3dB Bandwidth vs Supply Voltage, G = 1 120 8 1.0 TA = 25C TA = 25C RL = 10k TA = -55C TA = -55C FREQUENCY (kHz) TA = 125C 100 0.8 7 105 TA = 25C 95 90 85 80 TA = 25C 6 SLEW RATE (V/s) 110 FREQUENCY (kHz) Slew Rate vs Supply Voltage, G=1 -3dB Bandwidth vs Supply Voltage, G = 10 TA = 25C 115 1990 G12 TA = 125C 5 4 -SR 0.6 +SR 0.4 0.2 75 70 3 0 2 6 8 4 10 12 SUPPLY VOLTAGE (V) 14 0 0 16 2 6 8 4 10 12 SUPPLY VOLTAGE (V) 1990 G13 0 1.0 TA = 25C RL = 10k 0.6 VS = 15V RL = 10k 0.5 +SR 0.2 0.1 -SR SLEW RATE (V/s) SLEW RATE (V/s) -SR 0.6 +SR 0.4 0.2 0 0 2 8 6 10 12 4 SUPPLY VOLTAGE (V) 14 16 1990 G16 8 6 10 12 4 SUPPLY VOLTAGE (V) 0 -50 -25 14 16 Slew Rate vs Temperature G = 10 0.8 0.3 2 1990 G15 Slew Rate vs Temperature G=1 0.4 SLEW RATE (V/s) 16 1990 G14 Slew Rate vs Supply Voltage, G = 10 0.5 14 VS = 15V RL = 10k 0.4 0.3 -SR +SR 0.2 0.1 50 25 75 0 TEMPERATURE (C) 100 125 1990 G17 0 -50 -25 50 25 75 0 TEMPERATURE (C) 100 125 1990 G18 1990fb 11 LT1990 U W TYPICAL PERFOR A CE CHARACTERISTICS Power Supply Rejection Ratio vs Frequency 70 G = 10 G=1 100 10 VS = 5V, 0V TA = 25C 1 100 10k 1k FREQUENCY (Hz) 60 VS = 5V, 0V TA = 25C G=1 50 40 30 G = 10 20 10 0 -10 -20 SETTLING TIME (s) SETTLING TIME (s) 0.01% OF STEP 0.01% OF STEP 0.1% OF STEP 0.01% OF STEP 260 0.01% OF STEP 240 220 200 0.1% OF STEP 180 0.1% OF STEP 160 8 140 -10 -8 -6 -4 -2 0 2 4 OUTPUT STEP (V) 10 VS = 1.5V TO 15V TA = 25C 1000 100 6 8 1 10 10 100 1000 FREQUENCY (Hz) 10000 1990 G24 Overshoot vs Capacitive Load 30 VS = 1.5V TO 15V TA = 25C G=1 VOUT = 50mV GAIN = 1 RL = 10k 25 OVERSHOOT (%) NOISE VOLTAGE (10V/DIV) 50 1990 G21 0.01 to 1Hz Noise Voltage REF 10 20 30 40 TIME AFTER POWER-UP (S) 1990 G23 0.1 to 10Hz Noise Voltage VS = 1.5V TO 15V TA = 25C G=1 0 10000 280 1990 G22 NOISE VOLTAGE (10V/DIV) -40 Voltage Noise Density vs Frequency VS = 15V RL = 10k 300 50 6 -20 100k 200k 1k 10k FREQUENCY (Hz) 320 VS = 15V RL = 10k 20 -10 -8 -6 -4 -2 0 2 4 OUTPUT STEP (V) 0 Settling Time vs Output Step, G = 10 60 0.1% OF STEP 20 1990 G20 Settling Time vs Output Step, G=1 30 40 -60 100 1990 G19 40 VS = 15V TA = 25C REFERRED TO INPUT -30 -40 10 100k 200k Warm-Up Drift vs Time 60 VOLTAGE NOISE DENSITY (nV/Hz) OUTPUT IMPEDANCE () 1k POWER SUPPLY REJECTION RATIO (dB) 5k CHANGE IN OFFSET VOLTAGE (V) Output Impedance vs Frequency REF 20 15 VS = 3V, 0V 10 VS = 15V 5 0 1 2 3 4 5 6 TIME (S) 7 8 9 10 1990 G25 0 10 20 30 40 50 60 70 80 90 100 TIME (S) 1990 G26 10 100 1000 CAPACITIVE LOAD (pF) 10000 1990 G27 1990fb 12 LT1990 U W TYPICAL PERFOR A CE CHARACTERISTICS Small Signal Transient Response 1.5V VS = 3V, 0V G = 1, -1 RL = 10k VREF = 1.5V GND 1990 G28 50s/DIV Large Signal Transient Response 5V/DIV 50mV/DIV 50mV/DIV Small Signal Transient Response VS = 15V G = 1, -1 RL = 10k VREF = GND 1990 G29 50s/DIV GND VS = 15V G = 1, -1 RL = 10k VREF = GND 50s/DIV 1990 G30 W BLOCK DIAGRA R5 900k R7 10k 8 GAIN1 V+ 7 R1 1M R6 100k - -IN 2 R2 1M 6 OUT + +IN 3 V- 4 R10 10k R8 900k R3 40k 5 GAIN2 R4 40k 1 R9 100k 1990 SS REF U U U PI FU CTIO S REF (Pin 1): Reference Input. Sets the output level when the difference between the inputs is zero. -IN (Pin 2): Inverting Input. Connects a 1M resistor to the op amp's inverting input. Designed to permit high voltage operation. +IN (Pin 3): Noninverting Input. Connects a 1M resistor to the op amp's noninverting input. Designed to permit high voltage operation. V- (Pin 4): Negative Power Supply. Can be either ground (in single supply applications) or a negative voltage (in split supply applications). GAIN2 (Pin 5): Gain = 10 Select Input. Configures the amplifier for a gain of 10 when connected to the GAIN1 pin and the REF pin. The gain is equal to one when both GAIN2 and GAIN1 are open. See Applications section for additional functions. OUT (Pin 6): Output. VOUT = G * (V+IN - V-IN) + VREF, in the basic configuration. V+ (Pin 7): Positive Power Supply. Can range from 2.7V to 36V above the V- voltage. GAIN1 (Pin 8): Gain = 10 Select Input. Configures the amplifier for a gain of 10 when connected to the GAIN2 pin and the REF pin. The gain is equal to one when both GAIN1 and GAIN2 are open. See Applications section for additional functions. 1990fb 13 LT1990 U W U U APPLICATIO S I FOR ATIO Primary Features VCM+ 27 * V+ - 26 * VREF - 23 - VGAIN The LT1990 is a complete gain-block solution for high input common mode voltage applications, incorporating a low power precision operational amplifier providing railto-rail output swing along with on-chip precision thin-film resistors for high accuracy. The Block Diagram shows the internal architecture of the part. The on-chip resistors form a modified difference amplifier including a reference port for introducing offset or other additive waveforms. With pin-strapping alone either unity gain or gain of 10 is produced with high precision. The resistor network is designed to produce internal common-mode voltage division of 27 so that a very large input range is available compared to the power supply voltage(s) used by the LT1990 itself. The LT1990 is ideally suited to situations where relatively small signals need to be extracted from high voltage circuits, as is the case in many current monitoring instrumentation applications for example. With the ability to accept a range of input voltages well outside the limits of the local power rails and its greater than 1M input impedances, development of precision low power over-the-top and under-the-bottom instrumentation designs is greatly simplified with the LT1990 single chip solution over conventional discrete implementations. VCM- 27 * V- - 26 * VREF + 27 - VGAIN Classic Difference Amplifier Used in the basic difference amplifier topology where the gain G is pin-strap configurable to be unity or ten, the following relationship is realized: VO = G * (V+IN - V-IN) + VREF To operate in unity gain, the GAIN1 and GAIN2 pins are left disconnected. For G = 10 operation, the GAIN1 and GAIN2 pins are simply connected to the REF pin. The input common mode range capability is up to 250V, governed by the following relationships: For G = 1 and G = 10 where GAIN1 and GAIN2 are only tied together (not grounded,etc): VCM+ 27 * V+ - 26 * VREF - 23 VCM- 27 * V - - 26 * VREF + 27 For G = 10 where GAIN1 and GAIN2 are tied to a common potential VGAIN: For split supplies over about 11V, the full 250V common mode range is normally available (with VREF a small fraction of the supply). With lower supply voltages, an appropriate selection of VREF can tailor the input common mode range to a specific requirement. As an example, the following low supply voltage scenarios are readily implemented with the LT1990: Supply VREF VCM Range +3V 1.25V -5V to 25V (e.g. 12V automotive environment) +5V 1.25V -5V to 80V (e.g. 42V automotive environment) +5V 4.00V -77V to 8V (e.g. telecom environment; use downward signaling) Configuring Other Gains An intermediate gain G ranging between 1 and 10 may be produced by placing an adjustable resistance between the GAIN1 and GAIN2 pins according to the following nominal relationship: RGAIN (180k/(G - 1)) - 20k While the expression is exact, the value is approximate because the absolute resistance of the internal network could vary on a unit-to-unit basis by as much as 30% from the nominal figures and the external gain resistance is required to accommodate that deviation. Once adjusted, however, the gain stability is excellent by virtue of the -30ppm/C typical temperature coefficient offered by the on-chip thin-film resistor process. Preserving and Enhancing Common Mode Rejection The basic difference amplifier topology of the LT1990 requires that source impedances seen by the input pins +IN and -IN, should be matched to within a few tens of ohms to avoid increasing common mode induced errors beyond the basic production limits of the part. Known source imbalances beyond that level should be compensated for by the addition of series resistance to the lowerimpedance source. Also the source impedance of a signal connected to the REF pin must be on the order of a few ohms or less to preserve the high accuracy of the LT1990. 1990fb 14 LT1990 U W U U APPLICATIO S I FOR ATIO following relationship: While the LT1990 comes from the factory with an excellent CMRR, some precision applications with a large applied common mode voltage may require a method to trim out residual common mode error. This is easily accomplished by adding series resistance to each input, +IN and -IN, such that an adjustable resistance difference of 1k is provided. This is most easily realized by adding a fixed 1k in series with one of the inputs, and a 2k trimmer in series with the other as shown in Figure 1. The trim range of this configuration is 0.1% for the internal gain resistor matching, so a much more finely resolved correction is available using the LT1990 than is realizable with ordinary discrete solutions. In applications where the input common mode voltage is relatively constant and large (perhaps at or beyond the supply range), this same configuration can be treated as an offset adjustment. 1k VO = 10 * (V+IN - V-IN + VGAIN2 - VGAIN1) + VREF Unlike the main inputs, the GAIN1 and GAIN2 pins are clamped by substrate diodes and ESD structures, thus the operating voltage range of these pins is limited to V- - 0.2V to V- + 36V. If the GAIN inputs are brought beyond the operating input range, care must be taken to limit the input currents to less than 10mA to prevent damage to the device. For best results in this mode of operation the common mode voltage of the GAIN1 and GAIN2 pins should be equal to the REF pin voltage. Also, since the gain setting resistors associated with the GAIN1 and GAIN2 inputs are in the 10k area, low source impedances are particularly important to preserve the precision of the LT1990. This dual differential input mode of operation is used in the circuit as shown in Figure 2. - This circuit is a high efficiency H-bridge driver that is PWM modulated to provide a controlled current to an electromagnet coil. Since the common mode voltage of the current sense resistor RS varies with operating current and the coil properties, a differential feedback is required. In this application, it was desirable to allow the control input to utilize the wide common mode range port (+IN and -IN) so that constraints on input referencing are eliminated. The GAIN1 and GAIN2 pins always operate within the supply range and both ports operate with a gain of 10 to develop the loop error. The LTC1923 provides the loop integrator and PWM functions of the servo. LT1990 2k + Figure 1. Optional CMRR Trim Dual Differential-Input Arithmetic Block The internal resistor network topology of the LT1990 allows the GAIN1 and GAIN2 pins to be used as another differential input in addition to the normal +IN and -IN port. This can be a very useful function for implementing servo-loop differential error amplifiers, for example. In this mode of operation, the output is governed by the 10k PLLLPF RT RSLEW CT 330pF 82k VIN+ 100k 3 + 5 VDD G2 LT1990 20k 2 100k 10nF VDD 7 - REF 8 6 G1 SDSYNC VREF 1F 100k 100k 10nF 4 CNTRL PDRVB EAOUT NDRVB 10F MPA* L1 10H 1 FB VIN- VDD LTC1923 ICOIL = (VIN+ - VIN)/(10 * RS) (i.e. 1A FOR 1V) C1, C2, C3: TAIYO YUDEN JMK325BJ226MM-T (X7R) L1, L2: SUMIDA CDRH6D2B-220NC *MNA, MPA: SILICONIX Si9801 **MNB, MPB: SILICONIX Si9801 VDD VREF 1F 10k 10k AGND 1F PGND SS NDRVA ILIM PDRVA VSET CS + FAULT VTHRM CS - C3 22F C1 MNB** 22F MPB** L2 10H C2 22F MNA* 0.1 RS 0.1 ITEC H/C TEC + VTEC TEC - ICOIL ELECTROMAGNET COIL 1990 F02 Figure 2. PWM-Based 1A Electromagnet Current Controller 1990fb 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. 15 LT1990 U TYPICAL APPLICATIO Telecom Supply Current Monitor + LOAD IL Selectable Gain Amplifier Boosted Bidirectional Controlled Current Source +V 5V 48V +V - 3 7 + RS G2 LT1990 2 - 4 G1 VIN 5 6 + 8 7 + VIN- 2 - 4 G1 1 REF 1k G2 LT1990 VOUT 1 -77V VCM 8V VOUT = VREF - (10 * IL * RS) 3 REF VREF = 4V CZT751 5 6 VOUT 8 VCTL 3 + 6 LT1990 2 -V - + 10F 4 RSENSE 1 2N7002 4 5 IN OUT LT6650 1 GND FB 2 7 REF ILOAD 1nF 174k 1k GAIN_SEL (HI = 10X, LO = 1X) 20k CZT651 2N7002 -V 1990 AI01 1F ILOAD = VCTL/RSENSE 100mA EXAMPLE: FOR RSENSE =10, OUTPUT IS 1mA PER 10mV INPUT 1990 AI02 1990 AI04 Bidirectional Controlled Current Source +V VCTL 3 + 2 - 7 LT1990 4 1 REF -V 6 RSENSE ILOAD ILOAD = VCTL/RSENSE 5mA EXAMPLE: FOR RSENSE =100, OUTPUT IS 1mA PER 100mV INPUT 1990 AI03 U PACKAGE DESCRIPTIO S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) RECOMMENDED SOLDER PAD LAYOUT .010 - .020 x 45 (0.254 - 0.508) .045 .005 .050 BSC .008 - .010 (0.203 - 0.254) .245 MIN .160 .005 8 .053 - .069 (1.346 - 1.752) NOTE: 1. DIMENSIONS IN .050 (1.270) BSC .014 - .019 (0.355 - 0.483) TYP .150 - .157 (3.810 - 3.988) NOTE 3 .228 - .244 (5.791 - 6.197) INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) .030 .005 TYP 5 .004 - .010 (0.101 - 0.254) 0- 8 TYP .016 - .050 (0.406 - 1.270) .189 - .197 (4.801 - 5.004) NOTE 3 7 6 1 2 3 4 SO8 0303 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1787 Precision High Side Current Sense Amplifier On-Chip Precision Resistor Array LT1789 Micropower Instrumentation Amplifier Micropower, Precision, G = 1 to 1000 LTC1921 Dual -48V Supply and Fuse Monitor Withstands 200V Transients LT1991 High Accuracy Difference Amplifier Micropower, Precision, Pin Selectable G = -13 to 14 LT1995 30MHz, 1000V/s Gain Selectable Amplifier Pin Selectable G = -7 to 8 LT6910 Single Supply Programmable Gain Amplifier Digitally Controlled, SOT-23, G = 0 to 100 1990fb 16 LT 0406 REV B * PRINTED IN USA (c) LINEAR TECHNOLOGY CORPORATION 2004