LT1789IS8-10#PBF

LT1789-1/LT1789-10 Micropower, Single Supply Rail-to-Rail Output Instrumentation Amplifiers DESCRIPTION FEATURES n n n n n n n n n n n n n The LT®1789-1/LT1789-10 are micropower, precision instrumentation amplifiers that are optimized for single supply operation from 2.2V to 36V. The quiescent current is 95μA max, the inputs common mode to ground and the output swings within 110mV of ground. The gain is set with a single external resistor for a gain range of 1 to 1000 for the LT1789-1 and 10 to 1000 for the LT1789-10. Micropower: 95μA Supply Current Max Low Input Offset Voltage: 100μV Max Low Input Offset Voltage Drift: 0.5μV/°C Max Single Gain Set Resistor: G = 1 to 1000 (LT1789-1) G = 10 to 1000 (LT1789-10) Inputs Common Mode to V– Wide Supply Range: 2.2V to 36V Total Supply CMRR at G = 10: 96dB Min Gain Error: G = 10, 0.25% Max Gain Nonlinearity: G = 10, 40ppm Max Input Bias Current: 40nA Max PSRR at G = 10: 100dB Min 1kHz Voltage Noise: 48nV/√Hz 0.1Hz to 10Hz Noise: 1.5μVP-P The high accuracy of the LT1789-1 (40ppm maximum nonlinearity and 0.25% max gain error) is unmatched by other micropower instrumentation amplifiers. The LT1789-10 maximizes both the input common mode range and dynamic output range when an amplification of 10 or greater is required, allowing precise signal processing where other instrumentation amplifiers fail to operate. The LT1789-1/LT1789-10 are laser trimmed for very low input offset voltage, low input offset voltage drift, high CMRR and high PSRR. The output can handle capacitive loads up to 400pF (LT1789-1), 1000pF (LT1789-10) in any gain configuration while the inputs are ESD protected up to 10kV (human body). APPLICATIONS n n n n n n Portable Instrumentation Bridge Amplifiers Strain Gauge Amplifiers Thermocouple Amplifiers Differential to Single-Ended Converters Medical Instrumentation The LT1789-1/LT1789-10 are offered in the 8-pin SO package, requiring significantly less PC board area than discrete multi op amp and resistor designs. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION 0.5A to 4A Voltage Controlled Current Source C1 4700pF R1 90.9k VIN R2 10k VS C3 0.1μF VS 2 3 – + 7 6 LT1636 RISE TIME ≈ 250μs, 10% TO 90%, 1A TO 2A OUTPUT STEP INTO 0.25Ω LOAD TIP127* 7 R4 10k C2 3300pF 120Ω * ENSURE ADEQUATE POWER DISSIPATION CAPABILITY AT HIGHER VOLTAGES, CURRENTS AND DUTY CYCLES VS 5 4 VS = 3.3V TO 32V VIN ILOAD = RSENSE • 10 = 1A PER VOLT AS SHOWN 8k R3 100Ω + 3 3 8 6 1 LT1789-1 REF 2 1 5 – 4 RSENSE* 0.1Ω ILOAD 4 2 RLOAD* 1789 TA01 1789fc 1 LT1789-1/LT1789-10 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) Supply Voltage (V+ to V–)..........................................36V Input Differential Voltage ..........................................36V Input Current (Note 3) ......................................... ±20mA Output Short-Circuit Duration .......................... Indefinite Operating Temperature Range .................–40°C to 85°C Specified Temperature Range (Note 4) LT1789C-1, LT1789C-10 .......................–40°C to 85°C LT1789I-1, LT1789I-10 ........................–40°C to 85°C Storage Temperature Range .................. –65°C to 150°C Lead Temperature (Soldering, 10 sec)................... 300°C TOP VIEW RG 1 8 RG –IN 2 7 +VS +IN 3 6 OUT –VS 4 5 REF S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 190°C/W ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT1789CS8-1#PBF LT1789CS8-1#TRPBF 17891 8-Lead Plastic SO –40°C to 85°C LT1789IS8-1#PBF LT1789IS8-1#TRPBF 1789I1 8-Lead Plastic SO –40°C to 85°C LT1789CS8-10#PBF LT1789CS8-10#TRPBF 178910 8-Lead Plastic SO –40°C to 85°C LT1789IS8-10#PBF LT1789IS8-10#TRPBF 789I10 8-Lead Plastic SO –40°C to 85°C LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT1789CS8-1 LT1789CS8-1#TR 17891 8-Lead Plastic SO –40°C to 85°C LT1789IS8-1 LT1789IS8-1#TR 1789I1 8-Lead Plastic SO –40°C to 85°C LT1789CS8-10 LT1789CS8-10#TR 178910 8-Lead Plastic SO –40°C to 85°C LT1789IS8-10 LT1789IS8-10#TR 789I10 8-Lead Plastic SO –40°C to 85°C Consult LTC Marketing for parts specified with wider operating temperature ranges. 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/ 3V AND 5V ELECTRICAL CHARACTERISTICS supply, TA = 25°C, unless otherwise noted. VS = 3V, 0V; VS = 5V, 0V; RL = 20k, VCM = VREF = half LT1789-1 SYMBOL PARAMETER CONDITIONS G Gain Error (Note 6) LT1789-1, G = 1 + (200k/RG) LT1789-10, G = 10 • [1+ (200k/RG)] G = 1, VO = 0.1V to (+VS) – 1V Gain Nonlinearity (Note 6) Gain Range MIN TYP 1 LT1789-10 MAX MIN TYP MAX UNITS 1000 10 0.02 0.20 LT1789-1, VO = 0.1V to (+VS) – 0.3V LT1789-10, VO = 0.2V to (+VS) – 0.3V G = 10 (Note 2) G = 100 (Note 2) G = 1000 (Note 2) G = 1, VO = 0.1V to (+VS) – 1V 0.06 0.06 0.13 35 0.25 0.27 LT1789-1, VO = 0.1V to (+VS) – 0.3V LT1789-10, VO = 0.2V to 4.7V, VS = 5V (Note 8) G = 10 G = 100 G = 1000 12 18 90 40 75 1000 % 0.01 0.09 0.16 0.25 0.30 % % % ppm 15 20 100 100 100 ppm ppm ppm 100 1789fc 2 LT1789-1/LT1789-10 3V AND 5V ELECTRICAL CHARACTERISTICS supply, TA = 25°C, unless otherwise noted. VS = 3V, 0V; VS = 5V, 0V; RL = 20k, VCM = VREF = half LT1789-1 SYMBOL PARAMETER CONDITIONS TYP MAX TYP MAX UNITS G = 1000 15 100 20 160 μV Output Offset Voltage G = 1 (LT1789-1), G =10 (LT1789-10) 150 750 650 3000 μV IOS Input Offset Current (Note 6) 0.2 4 0.2 4 nA IB Input Bias Current en Input Noise Voltage, RTI (Referred to Input) (Note 6) 19 40 19 40 G = 1, fO = 0.1Hz to 10Hz G = 10 G = 100, 1000 5.0 1.5 1.0 VOST Total Input Referred Offset Voltage VOST = VOSI + VOSO/G VOSI Input Offset Voltage VOSO MIN LT1789-10 MIN nA μVP-P μVP-P μVP-P 4.6 1.1 Total RTI Noise = √eni2 + (eno/G)2 eni Input Noise Voltage Density, RTI fO = 1kHz (Note 7) 48 eno Output Noise Voltage Density, RTI fO = 1kHz (Note 3) 330 270 nV/√Hz in Input Noise Current fO = 0.1Hz to 10Hz 16 16 pAP-P Input Noise Current Density fO = 1kHz 62 62 fA/√Hz 1.6 GΩ 1.6 1.6 pF pF V RIN Input Resistance VIN = 0V to (+VS) – 1V (Note 6) CIN Input Capacitance Differential Common Mode VCM Input Voltage Range CMRR Common Mode Rejection Ratio PSRR Power Supply Rejection Ratio 0.75 85 1.6 52 0.75 1.6 1.6 0 +VS – 1 0 90 +VS – 1.2 nV/√Hz 1k Source Imbalance (Note 6) LT1789-1,VCM = 0V to (+VS) – 1V LT1789-10, VCM = 0V to (+VS) – 1.2V G=1 G = 10 G = 100 G = 1000 79 96 100 100 88 106 114 114 88 98 98 105 113 113 dB dB dB dB VS = 2.5V to 12.5V, VCM = VREF = 1V G=1 G = 10 G = 100 G = 1000 90 100 102 102 100 113 116 116 94 102 102 109 120 120 dB dB dB dB Minimum Supply Voltage 2.2 2.5 2.2 2.5 V IS Supply Current (Note 7) 67 95 67 95 μA VOL Output Voltage Swing LOW (Note 7) 54 100 62 110 mV VOH Output Voltage Swing HIGH (Note 7) ISC Short-Circuit Current Short to GND Short to +VS BW Bandwidth Slew Rate G=1 G = 10 G = 100 G = 1000 G = 10, VOUT = 0.5V to 4.5V Settling Time to 0.01% 4V Step SR RREFIN Reference Input Resistance IREFIN Reference Input Current AVREF Reference Gain to Output VREF = 0V +VS – 0.3 +VS – 0.19 +VS – 0.3 +VS – 0.19 2.2 8.5 V 2.2 8.5 60 30 3 0.2 25 12 1.5 mA mA kHz kHz kHz kHz 0.023 0.062 V/μs 240 190 μs 220 220 kΩ 2.7 2.7 μA 1 ±0.0001 1 ±0.0001 1789fc 3 LT1789-1/LT1789-10 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the temperature range of 0°C ≤ TA ≤ 70°C. VS = 3V, 0V; VS = 5V, 0V; RL = 20k, VREF = half supply, unless otherwise noted. (Note 4) LT1789-1 SYMBOL PARAMETER Gain Error (Note 6) Gain Nonlinearity (Note 6) CONDITIONS MIN TYP LT1789-10 MAX G = 1, VO = 0.3V to (+VS) – 1V l 0.25 VO = 0.3V to (+VS) – 0.5V G = 10 (Note 2) G = 100 (Note 2) l l 0.53 0.55 G = 1, VO = 0.3V to (+VS) – 1V l 185 LT1789-1, VO = 0.3V to (+VS) – 0.5V LT1789-10, VO = 0.3V to 4.7V, VS = 5V (Note 8) l G = 10 l G = 100 90 120 G/T Gain vs Temperature G < 1000 (Notes 2, 3) VOST Total Input Referred Offset Voltage VOST = VOSI + VOSO/G VOSI Input Offset Voltage l G = 1000 l 5 VOSIH Input Offset Voltage Hysteresis (Notes 3, 5) Output Offset Voltage G = 1 (LT1789-1), G = 10 (LT1789-10) l VOSOH Output Offset Voltage Hysteresis (Notes 3, 5) l 50 100 VOSI/T Input Offset Voltage Drift (RTI) (Note 3) l 0.2 (Note 3) l 1.5 (Note 6) l 3 MAX 0.30 0.53 UNITS % % ppm 5 150 VOSO Output Offset Voltage Drift TYP % 50 l VOSO/T MIN 10 3 130 130 ppm ppm 50 ppm/°C 190 µV 10 µV 3700 µV 300 900 µV 0.5 0.3 0.7 µV/°C 4 7 20 µV/°C 950 IOS Input Offset Current IOS/T Input Offset Current Drift IB Input Bias Current IB/T Input Bias Current Drift l VCM Input Voltage Range l 0.2 CMRR Common Mode Rejection Ratio 1k Source Imbalance (Note 6) LT1789-1, VCM = 0.2V to (+VS) – 1V LT1789-10, VCM = 0.2V to (+VS) – 1.5V l G=1 l G = 10 l G = 100, 1000 77 94 98 85 96 dB dB dB VS = 2.5V to 12.5V, VCM = VREF = 1V G=1 G = 10 G = 100, 1000 88 98 100 92 100 dB dB dB PSRR Power Supply Rejection Ratio (Note 6) VOL VOH Supply Current Output Voltage Swing LOW Output Voltage Swing HIGH l l l l 4.5 3 3 45 45 50 50 (+VS) – 1 0.2 nA pA/°C nA pA/°C (+VS) – 1.5 V l 2.5 2.5 V (Note 7) l 115 115 µA (Note 7) l 110 120 mV (Note 7) l +VS – 0.38 Minimum Supply Voltage IS 4.5 l +VS – 0.38 V 1789fc 4 LT1789-1/LT1789-10 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the temperature range of –40°C ≤ TA ≤ 85°C. VS = 3V, 0V; VS = 5V, 0V; RL = 20k, VREF = half supply, unless otherwise noted. (Note 4) LT1789-1 SYMBOL PARAMETER Gain Error (Note 6) Gain Nonlinearity (Note 6) CONDITIONS MIN TYP LT1789-10 MAX G = 1, VO = 0.3V to (+VS) – 1V l 0.30 VO = 0.3V to (+VS) – 0.5V G = 10 (Note 2) G = 100 (Note 2) l l 0.57 0.59 G = 1, VO = 0.3V to (+VS) – 1V l 250 LT1789-1, VO = 0.3V to (+VS) – 0.5V LT1789-10, VO = 0.3V to 4.7V, VS = 5V (Note 8) l G = 10 l G = 100 105 160 G/T Gain vs Temperature G < 1000 (Notes 2, 3) VOST Total Input Referred Offset Voltage VOST = VOSI + VOSO/G VOSI Input Offset Voltage l G = 1000 l 5 Input Offset Voltage Hysteresis (Notes 3, 5) VOSO Output Offset Voltage G = 1 (LT1789-1), G = 10 (LT1789-10) l VOSOH Output Offset Voltage Hysteresis (Notes 3, 5) l 50 100 VOSI/T Input Offset Voltage Drift (RTI) (Note 3) l 0.2 (Note 3) l 1.5 (Note 6) l 3 MAX 0.35 0.62 UNITS % % ppm 5 175 VOSIH Output Offset Voltage Drift TYP % 50 l VOSO/T MIN 10 3 150 170 ppm ppm 50 ppm/°C 205 µV 10 µV 4000 µV 300 900 µV 0.5 0.3 0.7 µV/°C 4 7 20 µV/°C 1050 IOS Input Offset Current IOS/T Input Offset Current Drift IB Input Bias Current IB/T Input Bias Current Drift l VCM Input Voltage Range l 0.2 CMRR Common Mode Rejection Ratio 1k Source Imbalance (Note 6) LT1789-1, VCM = 0.2V to (+VS) – 1V LT1789-10, VCM = 0.2V to (+VS) – 1.5V l G=1 l G = 10 l G = 100, 1000 75 92 96 84 94 dB dB dB VS = 2.5V to 12.5V, VCM = VREF = 1V G=1 G = 10 G = 100, 1000 86 96 98 90 98 dB dB dB PSRR Power Supply Rejection Ratio (Note 6) VOL VOH Supply Current Output Voltage Swing LOW Output Voltage Swing HIGH l l l l 5 3 3 50 50 50 50 +VS – 1 0.2 nA pA/°C nA pA/°C +VS – 1.5 V l 2.5 2.5 V (Note 7) l 125 125 µA (Note 7) l 120 130 mV (Note 7) l +VS – 0.40 Minimum Supply Voltage IS 5 l +VS – 0.40 V 1789fc 5 LT1789-1/LT1789-10 ELECTRICAL CHARACTERISTICS VS = ±15V, RL = 20k, VCM = VOUT = 0V, TA = 25°C, unless otherwise noted. LT1789-1 SYMBOL PARAMETER G CONDITIONS Gain Range MIN TYP LT1789-10 MAX MIN TYP MAX UNITS VOST LT1789-1, G = 1 + (200k/RG) LT1789-10, G = 10 • [1+ (200k/RG)] Gain Error VO = ±10V G=1 G = 10 (Note 2) G = 100 (Note 2) G = 1000 (Note 2) Gain Nonlinearity VO = ±10V G=1 G = 10 G = 100 G = 1000 Total Input Referred Offset Voltage VOST = VOSI + VOSO/G VOSI Input Offset Voltage G = 1000 30 235 30 295 μV VOSO Output Offset Voltage G = 1 (LT1789-1), G =10 (LT1789-10) 0.2 1 0.6 3.3 mV IOS Input Offset Current 0.2 4 0.2 4 nA IB Input Bias Current 17 40 17 40 nA en Input Noise Voltage, RTI 1 1000 10 1000 0.01 0.04 0.04 0.07 0.10 0.15 0.15 0.20 0.01 0.03 0.03 0.15 0.20 0.25 % % % % 8 1 6 20 20 10 20 100 5 5 25 40 40 160 ppm ppm ppm ppm fO = 0.1Hz to 10Hz G=1 G = 10 G = 100, 1000 5.0 1.5 1.0 μVP-P μVP-P μVP-P 4.6 1.1 Total RTI Noise = √eni2 + (eno/G)2 eni Input Noise Voltage Density, RTI fO = 1kHz 49 eno Output Noise Voltage Density, RTI fO = 1kHz 330 in Input Noise Current fO = 0.1Hz to 10Hz 19 19 pAP-P Input Noise Current Density fO = 1kHz 62 62 fA/√Hz 4.7 GΩ 20 17 pF pF V RIN Input Resistance CIN Input Capacitance VCM Input Voltage Range CMRR Common Mode Rejection Ratio PSRR Power Supply Rejection Ratio 2 Differential Common Mode LT1789-1 VS = ±1.25V to ±16V LT1789-10 VS = ±1.50V to ±16V G=1 G = 10 G = 100, 1000 Supply Current VO Output Voltage Swing ISC Short-Circuit Current 2 20 17 –14 –15 nV/√Hz nV/√Hz –14 89 108 117 93 102 108 123 dB dB dB 94 104 102 107 118 121 100 106 115 123 dB dB dB ±1.25 85 ±14.5 Short to –VS Short to +VS 95 80 98 102 Minimum Supply Voltage IS 53 270 4.7 –15 1k Source Imbalance, VCM = –15V to 14V G=1 G = 10 G = 100, 1000 90 ±14.7 2.2 8.5 130 85 ±14.5 ±14.7 2.2 8.5 ±1.50 V 130 μA V mA mA 1789fc 6 LT1789-1/LT1789-10 ELECTRICAL CHARACTERISTICS VS = ±15V, RL = 20k, VCM = VOUT = 0V, TA = 25°C, unless otherwise noted. LT1789-1 SYMBOL PARAMETER CONDITIONS BW Slew Rate G=1 G = 10 G = 100 G = 1000 VOUT = ±10V Settling Time to 0.01% 10V Step SR Bandwidth RREFIN Reference Input Resistance IREFIN Reference Input Current AVREF Reference Gain to Output MIN TYP LT1789-10 MAX MIN 60 30 3 0.2 0.012 VREF = 0V 0.026 0.028 TYP MAX UNITS 25 12 1.5 kHz kHz kHz kHz 0.066 V/μs 460 270 μs 220 220 kΩ 2.7 2.7 μA 1 ±0.0001 1 ±0.0001 The l denotes the specifications which apply over the temperature range of 0°C ≤ TA ≤ 70°C. VS = ±15V, RL = 20k, VCM = VREF = 0V, unless otherwise noted. (Note 4) LT1789-1 SYMBOL PARAMETER Gain Error Gain Nonlinearity CONDITIONS MIN VO = ±10V G=1 G = 10 (Note 2) G = 100 (Note 2) G = 1000 (Note 2) l l l l VO = ±10V G=1 G = 10 G = 100 G = 1000 l l l l G < 1000 (Notes 2, 3) l TYP LT1789-10 MAX MIN TYP MAX UNITS 0.15 0.38 0.38 0.43 0.20 0.43 0.48 % % % % 25 15 25 120 45 45 180 ppm ppm ppm ppm 50 ppm/°C 325 µV 30 µV 4 mV µV G/T Gain vs Temperature VOST Total Input Referred Offset Voltage VOST = VOSI + VOSO/G VOSI Input Offset Voltage G = 1000 l VOSIH Input Offset Voltage Hysteresis (Notes 3, 5) l VOSO Output Offset Voltage G=1 l VOSOH Output Offset Voltage Hysteresis (Notes 3, 5) l 50 120 400 1000 VOSI/T Input Offset Voltage Drift (RTI) (Note 3) l 0.2 0.7 0.3 0.8 µV/°C (Note 3) l 1.5 5 8 22 µV/°C 4.5 nA 5 50 5 285 8 30 8 1.2 VOSO/T Output Offset Voltage Drift IOS Input Offset Current l IOS/T Input Offset Current Drift l IB Input Bias Current l IB/T Input Bias Current Drift l VCM Input Voltage Range G = 1, Other Input Grounded l –14.8 CMRR Common Mode Rejection Ratio 1k Source Imbalance, VCM = –14.8V to 14V G=1 G = 10 G = 100, 1000 l l l 78 96 100 4.5 2 2 45 pA/°C 45 35 35 14 –14.8 91 100 nA pA/°C 14 V dB dB dB 1789fc 7 LT1789-1/LT1789-10 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the temperature range of 0°C ≤ TA ≤ 70°C. VS = ±15V, RL = 20k, VCM = VREF = 0V, unless otherwise noted. (Note 4) LT1789-1 SYMBOL PARAMETER CONDITIONS PSRR LT1789-1, VS = ±1.25V to ±16V LT1789-10, VS = ±1.50V to ±16V G=1 G = 10 G = 100, 1000 Power Supply Rejection Ratio MIN l l l TYP LT1789-10 MAX 92 102 104 MIN TYP MAX UNITS dB dB dB 98 104 Minimum Supply Voltage l ±1.25 ±1.50 V IS Supply Current l 150 150 µA VO Output Voltage Swing l ±14.25 ±14.25 V SR Slew Rate l 0.010 0.026 V/µs VOUT = ±10V The l denotes the specifications which apply over the temperature range of –40°C ≤ TA ≤ 85°C. VS = ±15V, RL = 20k, VCM = VREF = 0V, unless otherwise noted. (Note 4) LT1789-1 SYMBOL PARAMETER Gain Error Gain Nonlinearity G/T Gain vs Temperature CONDITIONS MIN VO = ±10V G=1 G = 10 (Note 2) G = 100 (Note 2) G = 1000 (Note 2) l l l l VO = ±10V G=1 G = 10 G = 100 G = 1000 l l l l G < 1000 (Notes 2, 3) l TYP 5 LT1789-10 MAX MIN MAX UNITS 0.20 0.57 0.57 0.62 0.25 0.62 0.67 % % % % 30 20 30 130 50 50 200 ppm ppm ppm ppm 50 ppm/°C 340 µV 30 µV 4.2 mV µV 50 TYP 5 VOST Total Input Referred Offset Voltage VOST = VOSI + VOSO/G VOSI Input Offset Voltage G = 1000 l VOSIH Input Offset Voltage Hysteresis (Notes 3, 5) l VOSO Output Offset Voltage G=1 l (Notes 3, 5) l 50 120 400 1000 0.2 0.7 0.3 0.8 µV/°C 1.5 5 8 22 µV/°C 5 nA VOSOH Output Offset Voltage Hysteresis VOSI/T Input Offset Voltage Drift (RTI) (Note 3) l VOSO/T Output Offset Voltage Drift (Note 3) l IOS Input Offset Current l IOS/T Input Offset Current Drift l Input Bias Current l l IB 305 8 30 8 1.3 5 2 2 50 IB/T Input Bias Current Drift VCM Input Voltage Range G = 1, Other Input Grounded l –14.8 CMRR Common Mode Rejection Ratio 1k Source Imbalance, VCM = –14.8V to 14V G=1 G = 10 G = 100, 1000 l l l 76 94 98 pA/°C 50 35 35 14 –14.8 89 98 nA pA/°C 14 V dB dB dB 1789fc 8 LT1789-1/LT1789-10 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the temperature range of –40°C ≤ TA ≤ 85°C. VS = ±15V, RL = 20k, VCM = VREF = 0V, unless otherwise noted. (Note 4) LT1789-1 SYMBOL PARAMETER CONDITIONS PSRR LT1789-1, VS = ±1.25V to ±16V LT1789-10, VS = ±1.50V to ±16V G=1 G = 10 G = 100, 1000 Power Supply Rejection Ratio IS VO SR MIN l l l UNITS dB dB dB 96 102 ±1.50 V Supply Current l 160 160 µA Output Voltage Swing l ±14.15 ±14.15 V Slew Rate l 0.008 0.024 V/µs VOUT = ±10V Note 5: 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 25°C, but the IC is cycled to 85°C I-grade (or 70°C C-grade) or – 40°C I-grade (0°C C-grade) before successive measurement. 60% of the parts will pass the typical limit on the data sheet. Note 6: VS = 5V limits are guaranteed by correlation to VS = 3V and VS = ±15V tests. Note 7: VS = 3V limits are guaranteed by correlation to VS = 5V and VS = ±15V tests. Note 8: This parameter is not tested at VS = 3V on the LT1789-10 due to an increase in sensitivity to test system noise. Actual performance is expected to be similar to performance at VS = 5V. (LT1789-1, LT1789-10) Input Bias Current vs Temperature 0 125°C 90 80 25°C –55°C 50 40 Input Bias Current vs Common Mode Input Voltage –10 VS = 5V, 0V VCM = 2.5V –12 –5 INPUT BIAS CURRENT (nA) INPUT BIAS CURRENT (nA) 110 SUPPLY CURRENT (μA) MAX ±1.25 120 –10 –15 –20 20 5 10 15 20 25 30 35 TOTAL SUPPLY VOLTAGE (V) 40 1789 G01 –25 –50 –25 50 25 0 75 TEMPERATURE (°C) 100 125 1789 G02 –55°C –14 –16 125°C –18 25°C –20 85°C –22 –24 –26 –28 30 0 TYP l Supply Current vs Supply Voltage 60 MIN 90 100 102 TYPICAL PERFORMANCE CHARACTERISTICS 70 MAX Minimum Supply Voltage 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: Does not include the effect of the external gain resistor RG. Note 3: This parameter is not 100% tested. Note 4: The LT1789C-1/ LT1789C-10 is guaranteed to meet specified performance from 0°C to 70°C and is designed, characterized and expected to meet these extended temperature limits, but is not tested at –40°C and 85°C. The LT1789I-1/ LT1789I-10 is guaranteed to meet the extended temperature limits. 100 TYP LT1789-10 VS = 5V, 0V VREF = 2.5V –30 –0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 COMMON MODE INPUT VOLTAGE (V) 1789 G03 1789fc 9 LT1789-1/LT1789-10 TYPICAL PERFORMANCE CHARACTERISTICS Output Voltage Swing vs Load Current Gain vs Frequency 4.4 1.4 4.2 1.2 VS = 5V, 0V VREF = 2.5V 4.0 1.0 125°C 0.8 25°C 0.6 0.4 SINK –55°C 0.2 60 50 40 G = 100 30 20 G = 10 10 0 1k 10k FREQUENCY (Hz) 100k 1789 G04 COMMON MODE REJECTION RATIO (dB) 120 VS = 5V, 0V VREF = 2.5V 110 G = 10 100 G = 100, 1000 90 G=1 80 70 60 50 40 10 1k 100 FREQUENCY (Hz) 10k 20k Negative Power Supply Rejection Ratio vs Frequency 140 120 G = 1000 VS = 5V, 0V VREF = 2.5V INPUT REFERRED G = 100 100 G = 10 80 G=1 60 40 20 0 10 100 1k FREQUENCY (Hz) 10k 20k 1879 G07 80 Positive Power Supply Rejection Ratio vs Frequency 140 G=1 80 60 40 20 0 100 1k FREQUENCY (Hz) 10 AV = 1 2 0 –2 –4 –8 AV ≥ 100 10 100 CAPACITIVE LOAD (pF) 4 –6 AV = 10 1 10k 20k VS = ±15V RL = 20k G=1 6 40 0 1789 G10 VS = 5V, 0V VREF = 2.5V INPUT REFERRED G = 10 100 8 50 10 100k G = 100, 1000 120 10 60 30 125 Settling Time to 0.01% vs Output Step 70 20 1k 10k FREQUENCY (Hz) 100 1789 G09 OUTPUT STEP (V) 1k 10 75 50 25 TEMPERATURE (°C) 0 1789 G06 VS = 5V, 0V VREF = 2.5V VOUT = 100mVP-P 90 OVERSHOOT (%) OUTPUT IMPEDANCE (Ω) 100 VS = 5V, 0V VREF = 2.5V 1 100 0.010 –50 –25 Overshoot vs Capacitive Load 100 FALLING 1789 G08 Output Impedance vs Frequency 10k 0.025 1789 G05 NEGATIVE POWER SUPPLY REJECTION RATIO (dB) Common Mode Rejection Ratio vs Frequency RISING 0.030 0.015 –20 100 10 0.035 0.020 G=1 –10 0 0.01 0.1 1 OUTPUT CURRENT (mA) 0.001 G = 1000 SLEW RATE (V/μs) 1.6 25°C VS = 5V, 0V 0.045 VREF = 2.5V G=1 0.040 RL = 20k POSITIVE POWER SUPPLY REJECTION RATIO (dB) 125°C 0.050 VS = 5V, 0V VREF = 2.5V 70 GAIN (dB) –55°C 4.8 SOURCE Slew Rate vs Temperature 80 OUTPUT VOLTAGE SWING—SINKING (V) OUTPUT VOLTAGE SWING—SOURCING (V) 5.0 4.6 (LT1789-1) –10 1000 1789 G11 0 100 300 400 200 SETTLING TIME (μs) 500 1789 G12 1789fc 10 LT1789-1/LT1789-10 TYPICAL PERFORMANCE CHARACTERISTICS Voltage Noise Density vs Frequency Current Noise Density vs Frequency G=1 G = 10 100 G = 100, 1000 1000 CURRENT NOISE DENSITY (fA/√Hz) VS = 5V, 0V VREF = 2.5V INPUT REFERRED 10 VS = 5V, 0V VREF = 2.5V 100 RS LT1789-1 10 1 10 100 FREQUENCY (Hz) 1k 10 100 FREQUENCY (Hz) 1 1k 1789 G13 1789 G14 0.1Hz to 10Hz Noise Voltage, G=1 0.1Hz to 10Hz Noise Voltage, RTI, G = 1000 VS = 5V, 0V VREF = 2.5V NOISE VOLTAGE (2μV/DIV) NOISE VOLTAGE (0.5μV/DIV) VS = 5V, 0V VREF = 2.5V 0 1 2 3 4 5 6 TIME (SEC) 7 8 0 9 10 1 3 2 4 5 6 TIME (SEC) 7 8 9 10 1789 G16 1789 G15 0.1Hz to 10Hz Noise Current Turn-On Characteristics 1.5 CHANGE IN OUTPUT VOLTAGE (V) VS = 5V, 0V VREF = 2.5V NOISE CURRENT (5pA/DIV) VOLTAGE NOISE DENSITY (nV/√Hz) 1000 (LT1789-1) VS = 5V, 0V VREF = 2.5V VCM = 2.5V G = 1000 TA = 25°C 0.5 –0.5 –1.5 0 1 2 3 4 5 6 TIME (SEC) 7 8 9 10 0 10 20 30 40 TIME (ms) 1789 G17 1789 G18 1789fc 11 LT1789-1/LT1789-10 TYPICAL PERFORMANCE CHARACTERISTICS Output Voltage Swing vs Load Current Gain vs Frequency SOURCE 25°C 1.4 4.2 4.0 1.2 VS = 5V, 0V VREF = 2.5V 1.0 125°C 0.8 25°C 0.6 0.4 SINK –55°C 0.2 60 0.01 0.1 1 OUTPUT CURRENT (mA) 40 G = 100 30 20 G = 10 10 110 VS = 5V, 0V VREF = 2.5V G = 10 100 90 80 70 60 50 40 10 100 1k FREQUENCY (Hz) 10k 20k –20 100 1k 10k FREQUENCY (Hz) Negative Power Supply Rejection Ratio vs Frequency 140 G = 1000 120 100 VS = 5V, 0V VREF = 2.5V INPUT REFERRED G = 100 80 G = 10 60 40 20 0 10 90 80 100 1k FREQUENCY (Hz) 10k 20k Positive Power Supply Rejection Ratio vs Frequency 140 G = 100, 1000 120 G = 10 VS = 5V, 0V VREF = 2.5V INPUT REFERRED 100 80 60 40 20 0 100 1k FREQUENCY (Hz) 10 10 6 50 40 0 10 G = 1000 4 2 0 –2 –4 –6 G = 100 –8 G = 10 100 CAPACITIVE LOAD (pF) 10k 20k VS = ±15V RL = 20k G = 10 8 30 125 100 1789 G26 VS = 5V, 0V VREF = 2.5V VOUT = 100mVP-P 60 10 1789 G27 75 Settling Time to 0.01% vs Output Step 70 20 100k 50 1789 G23 OUTPUT STEP (V) 1k OVERSHOOT (%) OUTPUT IMPEDANCE (Ω) 100 1k 10k FREQUENCY (Hz) 25 1789 G25 VS = 5V, 0V VREF = 2.5V 1 100 0 TEMPERATURE (°C) Overshoot vs Capacitive Load 10 –25 1789 G22 Output Impedance vs Frequency 100 FALLING 0.07 0.04 –50 100k 1789 G24 10k 0.08 0.05 –10 NEGATIVE POWER SUPPLY REJECTION RATIO (dB) COMMON MODE REJECTION RATIO (dB) G = 100, 1000 0.09 0.06 1789 G21 120 RISING 0 10 Common Mode Rejection Ratio vs Frequency 0.11 0.10 50 0 0.001 G = 1000 SLEW RATE (V/μs) 1.6 POSITIVE POWER SUPPLY REJECTION RATIO (dB) 125°C 0.12 VS = 5V, 0V VREF = 2.5V 70 GAIN (dB) –55°C 4.8 4.4 Slew Rate vs Temperature 80 OUTPUT VOLTAGE SWING—SINKING (V) OUTPUT VOLTAGE SWING—SOURCING (V) 5.0 4.6 (LT1789-10) 1000 1789 G28 –10 0 100 300 400 200 SETTLING TIME (μs) 500 1789 G29 1789fc 12 LT1789-1/LT1789-10 TYPICAL PERFORMANCE CHARACTERISTICS Voltage Noise Density vs Frequency Current Noise Density vs Frequency G = 10 100 G = 100 G = 1000 1000 CURRENT NOISE DENSITY (fA/√Hz) VS = 5V, 0V VREF = 2.5V INPUT REFERRED 10 VS = 5V, 0V VREF = 2.5V 100 RS LT1789-10 10 1 10 100 FREQUENCY (Hz) 1k 10 100 FREQUENCY (Hz) 1 1k 1789 G30 1789 G31 0.1Hz to 10Hz Noise Voltage, RTI, G = 10 0.1Hz to 10Hz Noise Voltage, RTI, G = 1000 VS = 5V, 0V VREF = 2.5V NOISE VOLTAGE (2μV/DIV) NOISE VOLTAGE (0.5μV/DIV) VS = 5V, 0V VREF = 2.5V 0 1 2 3 4 5 6 TIME (SEC) 7 8 0 9 10 1 3 2 4 5 6 TIME (SEC) 7 8 1789 G32 9 10 1789 G33 0.1Hz to 10Hz Noise Current Turn-On Characteristics 1.5 CHANGE IN OUTPUT VOLTAGE (V) VS = 5V, 0V VREF = 2.5V NOISE CURRENT (5pA/DIV) VOLTAGE NOISE DENSITY (nV/√Hz) 1000 (LT1789-10) VS = 5V, 0V VREF = 2.5V VCM = 2.5V G = 1000 TA = 25°C 0.5 –0.5 –1.5 0 1 2 3 4 5 6 TIME (SEC) 7 8 9 10 0 10 20 30 40 TIME (ms) 1789 G34 1789 G59 1789fc 13 LT1789-1/LT1789-10 TYPICAL PERFORMANCE CHARACTERISTICS Large-Signal Transient Response G = 1, 10, 100 (LT1789-1) Large-Signal Transient Response G = 1000 5V/DIV 5V/DIV VS = ±15V RL = 20k CL = 50pF 500μs/DIV 1789 G38 VS = ±15V RL = 20k CL = 50pF Small-Signal Transient Response G=1 2ms/DIV 1789 G39 Small-Signal Transient Response G = 10 20mV/DIV 20mV/DIV VS = 5V, 0V VREF = 2.5V RL = 20k CL = 50pF 100μs/DIV 1789 G40 VS = 5V, 0V VREF = 2.5V RL = 20k CL = 50pF Small-Signal Transient Response G = 100 100μs/DIV 1789 G41 Small-Signal Transient Response G = 1000 20mV/DIV 20mV/DIV VS = 5V, 0V VREF = 2.5V RL = 20k CL = 50pF 200μs/DIV 1789 G42 VS = 5V, 0V VREF = 2.5V RL = 20k CL = 50pF 2ms/DIV 1789 G43 1789fc 14 LT1789-1/LT1789-10 TYPICAL PERFORMANCE CHARACTERISTICS Large-Signal Transient Response G = 10, 100 5V/DIV (LT1789-10) Large-Signal Transient Response G = 1000 20mV/DIV 5V/DIV VS = ±15V RL = 20k CL = 50pF 500μs/DIV 1789 G44 Small-Signal Transient Response G = 10 VS = ±15V RL = 20k CL = 50pF 500μs/DIV Small-Signal Transient Response G = 100 20mV/DIV 1789 G45 VS = 5V, 0V VREF = 2.5V RL = 20k CL = 50pF 100μs/DIV 1789 G46 Small-Signal Transient Response G = 1000 20mV/DIV VS = 5V, 0V VREF = 2.5V RL = 20k CL = 50pF 200μs/DIV 1789 G47 VS = 5V, 0V VREF = 2.5V RL = 20k CL = 50pF 2ms/DIV 1789 G48 1789fc 15 LT1789-1/LT1789-10 TYPICAL PERFORMANCE CHARACTERISTICS Valid Output Voltage vs Input Common Mode Voltage VS = ±15V 3.0 TA = 25°C G=1 2.5 10 VALID OUTPUT VOLTAGE (V) VALID OUTPUT VOLTAGE (V) G≥2 Valid Output Voltage vs Input Common Mode Voltage VS = ±2.5V 5 0 –5 –10 Valid Output Voltage vs Input Common Mode Voltage VS = ±1.5V 1.5 TA = 25°C AV = 10 2.0 AV = 1 1.5 VALID OUTPUT VOLTAGE (V) 15 (LT1789-1) AV = 2 1.0 0.5 0 –0.5 –1.0 –1.5 TA = 25°C AV = 1 1.0 AV = 2 AV = 10 0.5 0 –0.5 –1.0 –2.0 –15 –15 10 –5 0 5 –10 INPUT COMMON MODE VOLTAGE (V) –2.5 –2.5 15 –1.5 1.5 –0.5 0.5 INPUT COMMON MODE VOLTAGE (V) 15V + VOUT VCM REF – 20K V– –15V VCM VOUT REF – VALID OUTPUT VOLTAGE (V) VALID OUTPUT VOLTAGE (V) 3 G=1 2 G=2 G = 10 0 1 3 4 2 INPUT COMMON MODE VOLTAGE (V) VCM 5 G=1 1 G=2 G = 10 0 0 2.0 0.5 1.5 2.5 1.0 INPUT COMMON MODE VOLTAGE (V) V– 3.0 3V V+ VD/2 VOUT REF – 1789 G51 TA = 25°C + LT1789-1 VD/2 20K 2 V+ VD/2 V– –1.5V 5V + – 3 4 0 REF Valid Output Voltage vs Input Common Mode Voltage VS = 3V TA = 25°C 1 VCM VD/2 1789 G50 Valid Output Voltage vs Input Common Mode Voltage VS = 5V 5 VOUT LT1789-1 20K V– –2.5V 1789 G49 V+ VD/2 LT1789-1 VD/2 1.5 1.5V + V+ VD/2 LT1789-1 VD/2 0 0.5 1.0 –1.0 –0.5 INPUT COMMON MODE VOLTAGE (V) 2.5V + V+ VD/2 –1.5 –1.5 2.5 20K 1789 G52 VOUT LT1789-1 VCM VD/2 REF – V– 20K 1789 G53 1789fc 16 LT1789-1/LT1789-10 TYPICAL PERFORMANCE CHARACTERISTICS Valid Output Voltage vs Input Common Mode Voltage VS = ±15V Valid Output Voltage vs Input Common Mode Voltage VS = ±2.5V 15 2.5 5 0 –5 –10 Valid Output Voltage vs Input Common Mode Voltage VS = ±1.5V AV = 100 1.5 1.5 TA = 25°C AV = 10 VALID OUTPUT VOLTAGE (V) G = 100 2.0 VALID OUTPUT VOLTAGE (V) 10 TA = 25°C 1.0 0.5 0 –0.5 –1.0 –1.5 TA = 25°C AV = 10 1.0 AV = 100 0.5 0 –0.5 –1.0 –2.0 –15 –15 10 –5 0 5 –10 INPUT COMMON MODE VOLTAGE (V) –2.5 –2.5 15 –1.5 1.5 –0.5 0 0.5 INPUT COMMON MODE VOLTAGE (V) 15V + VOUT REF – 0 0.5 1.0 –1.0 –0.5 INPUT COMMON MODE VOLTAGE (V) V– 20K VCM –15V VOUT V– 20K VCM REF – 1789 G56 3 TA = 25°C TA = 25°C G = 10 4 G = 100 3 2 1 0 1 3 4 2 INPUT COMMON MODE VOLTAGE (V) 5 G = 100 2 1 0 0 2.0 0.5 1.5 2.5 1.0 INPUT COMMON MODE VOLTAGE (V) + V+ VD/2 VCM VOUT REF – V– V+ VD/2 LT1789-10 VD/2 3.0 3V 5V + 20K Valid Output Voltage vs Input Common Mode Voltage VS = 3V Valid Output Voltage vs Input Common Mode Voltage VS = 5V 0 V– –1.5V 1789 G55 G = 10 VOUT LT1789-10 VD/2 –2.5V 1789 G54 5 V+ VD/2 REF – 1.5 1.5V + LT1789-10 VD/2 VALID OUTPUT VOLTAGE (V) VCM –1.5 –1.5 V+ VD/2 LT1789-10 VD/2 2.5 2.5V + V+ VD/2 VALID OUTPUT VOLTAGE (V) VALID OUTPUT VOLTAGE (V) G = 10 (LT1789-10) 20K 1789 G57 VOUT LT1789-10 VCM VD/2 REF – V– 20K 1789 G58 1789fc 17 LT1789-1/LT1789-10 BLOCK DIAGRAM V+ V+ 100k V+ 5.7k +IN 3 – RG 1 V– V– V+ V+ + R1 R2 110k/10k* 110k/100k* A1 5 REF VB V– + RG 8 A3 100k – 5.7k V+ –IN 2 – V– + V– R3 R4 110k/10k* 110k/100k* A2 6 OUT 7 V+ VB *LT1789-1/LT1789-10 V– 4 V– 1789 F01 Figure 1. Block Diagram APPLICATIONS INFORMATION Setting the Gain Input and Output Offset Voltage The gain of the LT1789-1 and LT1789-10 is set by the value of resistor RG, applied across pins 1 and 8. For the LT1789-1, the gain G will be: The offset voltage of the LT1789-1/LT1789-10 has two components: the output offset and the input offset. The total offset voltage referred to the input (RTI) is found by dividing the output offset by the programmed gain (G) and adding it to the input offset. At high gains the input offset voltage dominates, whereas at low gains the output offset voltage dominates. The total offset voltage is: G = 1+ 200k/RG and RG can be calculated from the desired gain by RG = 200k/(G – 1) For the LT1789-10, the gain G will be G =10 • (1 + 200k/RG) and RG can be calculated from the desired gain by To t a l i n p u t o f f s e t v o l t a g e = input offset + (output offset/G) (RTI) To t a l o u t p u t o f f s e t v o l t a g e = (input offset • G) + output offset (RTO) RG = 200k/(0.1 • G – 1) For the lowest achievable gain, RG may be set to infinity by leaving Pins 1 and 8 open. 1789fc 18 LT1789-1/LT1789-10 APPLICATIONS INFORMATION Reference Terminal Input Bias Current Return Path The output voltage of the LT1789-1/LT1789-10 (Pin 6) is referenced to the voltage on the reference terminal (Pin 5). Resistance in series with the REF pin must be minimized for best common mode rejection. For example, a 22Ω resistance from the REF pin to ground will not only increase the gain error by 0.02% but will lower the CMRR to 80dB. The low input bias current of the LT1789-1/LT1789-10 (19nA) and the high input impedance (1.6GΩ) allow the use of high impedance sources without introducing significant offset voltage errors, even when the full common mode range is required. However, a path must be provided for the input bias currents of both inputs when a purely differential signal is being amplified. Without this path the inputs will float high and exceed the input common mode range of the LT1789-1/LT1789-10, resulting in a saturated input stage. Figure 3 shows three examples of an input bias current path. The first example is of a purely differential signal source with a 10kΩ input current path to ground. Since the impedance of the signal source is low, only one resistor is needed. Two matching resistors are needed for higher impedance signal sources as shown in the second example. Balancing the input impedance improves both common mode rejection and DC offset. The need for input resistors is eliminated if a center tap is present as shown in the third example. Output Offset Trimming The LT1789-1/LT1789-10 is laser trimmed for low offset voltage so that no external offset trimming is required for most applications. In the event that the offset needs to be adjusted, the circuit in Figure 2 is an example of an optional offset adjust circuit. The op amp buffer provides a low impedance to the REF pin where resistance must be kept to a minimum for best CMRR and lowest gain error. – 1 LT1789-1/-10 8 REF 3 + +IN 5 RG V+ OUTPUT 6 1 2 + 2 – –IN 3 100Ω LT1880 ±10mV ADJUSTMENT RANGE 10mV 10k 100Ω –10mV V– 1789 F02 Figure 2. Optional Trimming of Output Offset Voltage – THERMOCOUPLE – LT1789-1/ LT1789-10 RG MICROPHONE, HYDROPHONE, ETC 10k LT1789-1/ LT1789-10 RG + – + 200k LT1789-1/ LT1789-10 RG + 200k CENTER-TAP PROVIDES BIAS CURRENT RETURN 1789 F03 Figure 3. Providing an Input Common Mode Current Path 1789fc 19 LT1789-1/LT1789-10 APPLICATIONS INFORMATION Output Voltage vs Input Common Mode Voltage All instrumentation amplifiers have limiting factors that can cause an output to be invalid (the output is not equal to the input differential voltage multiplied by the gain) even though the output appears to be operating in a linear region. Limiting factors such as input voltage range and output swing can be easily measured, however, there are also internal nodes that can limit. These internal nodes cannot be measured externally and can lead to erroneous output readings. To ensure a valid output for a given input common mode voltage and input differential voltage, the following four limiting factors must be taken into consideration (refer to the block diagram): 1) The input voltage ranges of the input amplifiers A1 and A2. 2) The output swings of the input amplifiers A1 and A2 (internal nodes). 3) The input voltage range of the output amplifier A3 (internal node). 4) The output swing of the output amplifier A3. These limits can be determined using the relationships below. 1) The input voltage range limits can be found in the electrical tables. 2) The output voltages of the input amplifiers A1 and A2 can be found by the following formulas: VOUT A1 = (VD/2)(G)(R1/R2) + VCM + 0.6V VOUT A2 = (–VD/2)(G)(R1/R2) + VCM + 0.6V Where VD is the input differential voltage and VCM is the input common mode voltage. The typical output swing limits for A1 and A2 can be found in the Output Swing vs Load Current typical performance curve, using R1 + R2 as the load resistance. The LT1789-10 is less susceptible to this limiting factor because the gain is taken in the output stage. 3) The voltage on the inputs to the output amplifier A3 can be determined by the following formula: VIN A3 = (VOUT A1 – VREF)(R2/(R1 + R2)) The input voltage range of A3 has the same input limits as the LT1789-1. This limiting factor is more prevalent with single supplies, where both the reference voltage and input common mode voltage are near V+. This is also more of a concern with the LT1789-10 because the ratio of R1:R2 is 1:10 instead of 1:1. 4) The output voltage swing limits are also found in the electrical tables. The Output Voltage vs Input Common Mode Voltage typical performance curves show the regions of operation for the three supply voltages specified. Single Supply Operation There are usually two types of input signals that need to be processed; differential signals, like the output of a bridge or single ended signals, such as the output from a thermistor. Both signals require special consideration when operating with a single supply. When processing differential signals , REF (Pin 5) must be brought above the negative supply (Pin 4) to allow the output to process both the positive and negative going input signal. The maximum output operating range is obtained by setting the voltage on the REF pin to half supply. This must be done with a low impedance source to minimize CMRR and gain errors. For single ended input signals, the REF pin can be at the same potential as the negative supply provided the output of the instrumentation amplifier remains inside the specified operating range. This maximizes the output range, however the smallest input signal that can be processed is limited by the output swing to the negative supply. This limitation usually becomes dominant when gain is taken in the input stage and the common mode input voltage is close to either supply rail. 1789fc 20 LT1789-1/LT1789-10 TYPICAL APPLICATIONS Single Supply Positive Integrator 3 VIN VS + 7 LT1789-1 REF 1 2 – VS R1 6 10k 8 5 3 + C1 100μF 4 R2 10Ω + 1 LT1636 2 – VOUT 4 RESET 1789 TA02 VS = 2.7V TO 32V TIME CONSTANT = (R1)(C1) = 1 SECOND AS SHOWN Avalanche Photo Diode Module Bias Current Monitor APD HIGH VOLTAGE BIAS INPUT FOR OPTIONAL “ZERO CURRENT” FEEDBACK TO APD BIAS REGULATOR, SEE APPENDIX A, APPLICATION NOTE 92 1k* 1% 1μF 100V 1μF 100V 100k* 100k* VOUT = 20V TO 90V TO APD Q1 1N4690 5.6V 1M* 0.2μF 5V – 10k A1 LT1789-1 30k + Q2 MPSA42 0.2μF 5V 1μF 6 20k + 2 S2 5 – 20k* 1M* –3.5V –3.5V 20k 200k* 12 13 OUTPUT 0V TO 1V = 0mA TO 1mA A2 LT1006 1μF 14 S1 18 5V 5V 3 15 + * = 0.1% METAL FILM RESISTOR 1μF 100V = TECATE CMC100105MX1825 # CIRCLED NUMBERS = LTC1043 PIN NUMBER + S3 –3.5V TO AMPLIFIERS 22μF 22μF = 1N4148 = TP0610L 16 17 4 0.056μF † FOR MORE INFORMATION REFER TO APPLICATION NOTE 92 5V 1789 TA05 1789fc 21 LT1789-1/LT1789-10 PACKAGE DESCRIPTION S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) .050 BSC .189 – .197 (4.801 – 5.004) NOTE 3 .045 ±.005 8 .245 MIN .160 ±.005 .010 – .020 × 45° (0.254 – 0.508) NOTE: 1. DIMENSIONS IN 5 .150 – .157 (3.810 – 3.988) NOTE 3 1 RECOMMENDED SOLDER PAD LAYOUT .053 – .069 (1.346 – 1.752) 0°– 8° TYP .016 – .050 (0.406 – 1.270) 6 .228 – .244 (5.791 – 6.197) .030 ±.005 TYP .008 – .010 (0.203 – 0.254) 7 .014 – .019 (0.355 – 0.483) TYP 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) 2 3 4 .004 – .010 (0.101 – 0.254) .050 (1.270) BSC SO8 0303 1789fc 22 LT1789-1/LT1789-10 REVISION HISTORY (Revision history begins at Rev C) REV DATE DESCRIPTION PAGE NUMBER C 5/10 Updated Input Noise Current Density Spec 6 1789fc 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. 23 LT1789-1/LT1789-10 TYPICAL APPLICATION Voltage Controlled Current Source 3V TO 32V 3 VIN + 7 8 RG 1 2 6 LT1789-1 REF 5 – R1 1k 4 IL LOAD IL = AV • VIN/R1 1789 TA03 AV = 1 + 200k RG 10°C to 40°C Thermometer VS+ 4 LT1790 6 –1.25 1 2 29.4k 1% 3 6 LT1789-10 1 2 100k @ 25°C 7 8 36.5k 0.5% THERMISTOR THERMOMETRICS DC95G104V VS+ + 5 – 4 866k 1% 56.2k 1% VOUT = 2.5V AT 25°C + 50mV/°C OVER 10°C TO 40°C LINEARITY = 0.3°C ACCURACY = 1°C WORST CASE TOLERANCE STACK-UP VS+ = 4V TO 18V 1789 TA04 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC1100 Precision Chopper-Stabilized Instrumentation Amplifier Best DC Accuracy LT1101 Precision, Micropower, Single Supply Instrumentation Amplifier Fixed Gain of 10 or 100, IS