LT1789CS8-1-PBF

FEATURES n n n n LT1789-1/LT1789-10 Micropower, Single Supply Rail-to-Rail Output Instrumentation Amplifiers DESCRIPTION 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. 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). 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. n n n n n n n n n 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 APPLICATIONS n n n n n n Portable Instrumentation Bridge Amplifiers Strain Gauge Amplifiers Thermocouple Amplifiers Differential to Single-Ended Converters Medical Instrumentation TYPICAL APPLICATION 0.5A to 4A Voltage Controlled Current Source C1 4700pF VS VIN R2 10k VS = 3.3V TO 32V VIN ILOAD = RSENSE • 10 = 1A PER VOLT AS SHOWN RISE TIME ≈ 250μs, 10% TO 90%, 1A TO 2A OUTPUT STEP INTO 0.25Ω LOAD + 3 – 4 R1 90.9k VS 2 7 LT1636 5 6 C3 0.1μF R3 100Ω VS 7 R4 10k 6 REF 1 5 4 8k 120Ω TIP127* + 3 8 3 1 2 4 * ENSURE ADEQUATE POWER DISSIPATION CAPABILITY AT HIGHER VOLTAGES, CURRENTS AND DUTY CYCLES RSENSE* 0.1Ω ILOAD LT1789-1 C2 3300pF – 2 RLOAD* 1789 TA01 1789fc 1 LT1789-1/LT1789-10 ABSOLUTE MAXIMUM RATINGS (Note 1) PIN CONFIGURATION TOP VIEW RG 1 –IN 2 +IN 3 –VS 4 8 RG 7 +VS 6 OUT 5 REF 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 S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 190°C/W ORDER INFORMATION LEAD FREE FINISH LT1789CS8-1#PBF LT1789IS8-1#PBF LT1789CS8-10#PBF LT1789IS8-10#PBF LEAD BASED FINISH LT1789CS8-1 LT1789IS8-1 LT1789CS8-10 LT1789IS8-10 TAPE AND REEL LT1789CS8-1#TRPBF LT1789IS8-1#TRPBF LT1789CS8-10#TRPBF LT1789IS8-10#TRPBF TAPE AND REEL LT1789CS8-1#TR LT1789IS8-1#TR LT1789CS8-10#TR LT1789IS8-10#TR PART MARKING 17891 1789I1 178910 789I10 PART MARKING 17891 1789I1 178910 789I10 PACKAGE DESCRIPTION 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO PACKAGE DESCRIPTION 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO TEMPERATURE RANGE –40°C to 85°C –40°C to 85°C –40°C to 85°C –40°C to 85°C TEMPERATURE RANGE –40°C to 85°C –40°C to 85°C –40°C to 85°C –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/ supply, TA = 25°C, unless otherwise noted. SYMBOL PARAMETER G Gain Range Gain Error (Note 6) 3V AND 5V ELECTRICAL CHARACTERISTICS CONDITIONS LT1789-1, G = 1 + (200k/RG) LT1789-10, G = 10 • [1+ (200k/RG)] G = 1, VO = 0.1V to (+VS) – 1V 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 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 MIN 1 VS = 3V, 0V; VS = 5V, 0V; RL = 20k, VCM = VREF = half LT1789-1 TYP MAX 1000 10 0.02 0.20 1000 % MIN LT1789-10 TYP MAX UNITS Gain Nonlinearity (Note 6) 0.06 0.06 0.13 35 0.25 0.27 100 0.01 0.09 0.16 0.25 0.30 % % % ppm 12 18 90 40 75 15 20 100 100 100 ppm ppm ppm 1789fc 2 LT1789-1/LT1789-10 supply, TA = 25°C, unless otherwise noted. SYMBOL PARAMETER VOST VOSI VOSO IOS IB en Input Offset Voltage Output Offset Voltage Input Offset Current Input Bias Current Input Noise Voltage, RTI (Referred to Input) 3V AND 5V ELECTRICAL CHARACTERISTICS CONDITIONS G = 1000 G = 1 (LT1789-1), G =10 (LT1789-10) (Note 6) (Note 6) G = 1, fO = 0.1Hz to 10Hz G = 10 G = 100, 1000 fO = 1kHz (Note 7) fO = 0.1Hz to 10Hz fO = 1kHz VIN = 0V to (+VS) – 1V (Note 6) Differential Common Mode 0 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 VS = 2.5V to 12.5V, VCM = VREF = 1V G=1 G = 10 G = 100 G = 1000 (Note 7) (Note 7) (Note 7) Short to GND Short to +VS G=1 G = 10 G = 100 G = 1000 G = 10, VOUT = 0.5V to 4.5V 4V Step VREF = 0V 0.75 MIN Total Input Referred Offset Voltage VOST = VOSI + VOSO/G VS = 3V, 0V; VS = 5V, 0V; RL = 20k, VCM = VREF = half LT1789-1 TYP 15 150 0.2 19 5.0 1.5 1.0 48 330 16 62 1.6 1.6 1.6 +VS – 1 0 0.75 85 MAX 100 750 4 40 MIN LT1789-10 TYP 20 650 0.2 19 4.6 1.1 52 270 16 62 1.6 1.6 1.6 +VS – 1.2 90 MAX 160 3000 4 40 UNITS μV μV nA nA μVP-P μVP-P μVP-P nV/√Hz nV/√Hz pAP-P fA/√Hz GΩ pF pF V Total RTI Noise = √eni2 + (eno/G)2 eni eno in RIN CIN VCM CMRR Input Noise Voltage Density, RTI Input Noise Current Input Noise Current Density Input Resistance Input Capacitance Input Voltage Range Common Mode Rejection Ratio Output Noise Voltage Density, RTI fO = 1kHz (Note 3) 79 96 100 100 90 100 102 102 88 106 114 114 100 113 116 116 2.2 67 54 2.5 95 100 88 98 98 105 113 113 dB dB dB dB dB dB dB dB 2.5 95 110 V μA mV V mA mA kHz kHz kHz kHz V/μs μs kΩ μA PSRR Power Supply Rejection Ratio 94 102 102 109 120 120 2.2 67 62 Minimum Supply Voltage IS VOL VOH ISC BW Supply Current Output Voltage Swing LOW Output Voltage Swing HIGH Short-Circuit Current Bandwidth +VS – 0.3 +VS – 0.19 2.2 8.5 60 30 3 0.2 0.023 240 220 2.7 1 ±0.0001 +VS – 0.3 +VS – 0.19 2.2 8.5 25 12 1.5 0.062 190 220 2.7 1 ±0.0001 SR RREFIN IREFIN AVREF Slew Rate Settling Time to 0.01% Reference Input Resistance Reference Input Current Reference Gain to Output 1789fc 3 LT1789-1/LT1789-10 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER Gain Error (Note 6) CONDITIONS G = 1, VO = 0.3V to (+VS) – 1V VO = 0.3V to (+VS) – 0.5V G = 10 (Note 2) G = 100 (Note 2) Gain Nonlinearity (Note 6) G = 1, VO = 0.3V to (+VS) – 1V l l l l 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 MIN TYP MAX 0.25 0.53 0.55 185 0.30 0.53 MIN LT1789-10 TYP MAX UNITS % % % ppm 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 G/T VOST VOSI VOSIH VOSO VOSOH VOSI/T VOSO/T IOS IOS/T IB IB/T VCM CMRR Gain vs Temperature Input Offset Voltage Input Offset Voltage Hysteresis Output Offset Voltage Output Offset Voltage Hysteresis Input Offset Voltage Drift (RTI) Output Offset Voltage Drift Input Offset Current Input Offset Current Drift Input Bias Current Input Bias Current Drift Input Voltage Range Common Mode Rejection Ratio (Note 6) G < 1000 (Notes 2, 3) G = 1000 (Notes 3, 5) G = 1 (LT1789-1), G = 10 (LT1789-10) (Notes 3, 5) (Note 3) (Note 3) (Note 6) l 90 120 5 50 150 3 50 0.2 1.5 3 45 50 0.2 (+VS) – 1 0.2 50 10 950 100 0.5 4 4.5 3 300 0.3 7 3 5 130 130 50 190 10 3700 900 0.7 20 4.5 45 (+VS) – 1.5 ppm ppm ppm/°C µV µV µV µV µV/°C µV/°C nA pA/°C nA pA/°C V Total Input Referred Offset Voltage VOST = VOSI + VOSO/G l l l l l l l l l l l 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 VS = 2.5V to 12.5V, VCM = VREF = 1V G=1 G = 10 G = 100, 1000 (Note 7) (Note 7) (Note 7) l l l l l l 77 94 98 88 98 100 2.5 115 110 85 96 dB dB dB dB dB dB 2.5 115 120 V µA mV V PSRR Power Supply Rejection Ratio 92 100 Minimum Supply Voltage IS VOL VOH Supply Current Output Voltage Swing LOW Output Voltage Swing HIGH l +VS – 0.38 +VS – 0.38 1789fc 4 LT1789-1/LT1789-10 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER Gain Error (Note 6) CONDITIONS G = 1, VO = 0.3V to (+VS) – 1V VO = 0.3V to (+VS) – 0.5V G = 10 (Note 2) G = 100 (Note 2) Gain Nonlinearity (Note 6) G = 1, VO = 0.3V to (+VS) – 1V l l l l 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 MIN TYP MAX 0.30 0.57 0.59 250 0.35 0.62 MIN LT1789-10 TYP MAX UNITS % % % ppm 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 G/T VOST VOSI VOSIH VOSO VOSOH VOSI/T VOSO/T IOS IOS/T IB IB/T VCM CMRR Gain vs Temperature Input Offset Voltage Input Offset Voltage Hysteresis Output Offset Voltage Output Offset Voltage Hysteresis Input Offset Voltage Drift (RTI) Output Offset Voltage Drift Input Offset Current Input Offset Current Drift Input Bias Current Input Bias Current Drift Input Voltage Range Common Mode Rejection Ratio (Note 6) G < 1000 (Notes 2, 3) G = 1000 (Notes 3, 5) G = 1 (LT1789-1), G = 10 (LT1789-10) (Notes 3, 5) (Note 3) (Note 3) (Note 6) l 105 160 5 50 175 3 50 0.2 1.5 3 50 50 0.2 +VS – 1 0.2 50 10 1050 100 0.5 4 5 3 300 0.3 7 3 5 150 170 50 205 10 4000 900 0.7 20 5 50 +VS – 1.5 ppm ppm ppm/°C µV µV µV µV µV/°C µV/°C nA pA/°C nA pA/°C V Total Input Referred Offset Voltage VOST = VOSI + VOSO/G l l l l l l l l l l l 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 VS = 2.5V to 12.5V, VCM = VREF = 1V G=1 G = 10 G = 100, 1000 (Note 7) (Note 7) (Note 7) l l l l l l 75 92 96 86 96 98 2.5 125 120 84 94 dB dB dB dB dB dB 2.5 125 130 V µA mV V PSRR Power Supply Rejection Ratio 90 98 Minimum Supply Voltage IS VOL VOH Supply Current Output Voltage Swing LOW Output Voltage Swing HIGH l +VS – 0.40 +VS – 0.40 1789fc 5 LT1789-1/LT1789-10 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER G Gain Range CONDITIONS VS = ±15V, RL = 20k, VCM = VOUT = 0V, TA = 25°C, unless otherwise noted. LT1789-1 MIN 1 TYP MAX 1000 10 0.01 0.04 0.04 0.07 8 1 6 20 30 0.2 0.2 17 fO = 0.1Hz to 10Hz G=1 G = 10 G = 100, 1000 fO = 1kHz fO = 0.1Hz to 10Hz fO = 1kHz 2 Differential Common Mode –15 1k Source Imbalance, VCM = –15V to 14V G=1 G = 10 G = 100, 1000 LT1789-1 VS = ±1.25V to ±16V LT1789-10 VS = ±1.50V to ±16V G=1 G = 10 G = 100, 1000 80 98 102 94 104 102 89 108 117 107 118 121 ±1.25 85 ±14.5 Short to –VS Short to +VS ±14.7 2.2 8.5 130 ±14.5 85 ±14.7 2.2 8.5 5.0 1.5 1.0 49 330 19 62 4.7 20 17 –14 –15 2 90 0.10 0.15 0.15 0.20 20 10 20 100 235 1 4 40 1000 % % % % ppm ppm ppm ppm μV mV nA nA μVP-P μVP-P μVP-P 95 nV/√Hz nV/√Hz pAP-P fA/√Hz GΩ pF pF V dB dB dB dB dB dB ±1.50 130 V μA V mA mA MIN 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 Input Offset Voltage Output Offset Voltage Input Offset Current Input Bias Current Input Noise Voltage, RTI G = 1000 G = 1 (LT1789-1), G =10 (LT1789-10) LT1789-10 TYP MAX UNITS 0.01 0.03 0.03 0.15 0.20 0.25 5 5 25 30 0.6 0.2 17 40 40 160 295 3.3 4 40 VOST VOSI VOSO IOS IB en 4.6 1.1 53 270 19 62 4.7 20 17 –14 Total RTI Noise = √eni2 + (eno/G)2 eni eno in RIN CIN VCM CMRR Input Noise Voltage Density, RTI Input Noise Current Input Noise Current Density Input Resistance Input Capacitance Input Voltage Range Common Mode Rejection Ratio Output Noise Voltage Density, RTI fO = 1kHz 93 102 108 123 PSRR Power Supply Rejection Ratio 100 106 115 123 Minimum Supply Voltage IS VO ISC Supply Current Output Voltage Swing Short-Circuit Current 1789fc 6 LT1789-1/LT1789-10 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER BW Bandwidth CONDITIONS G=1 G = 10 G = 100 G = 1000 VOUT = ±10V 10V Step VREF = 0V VS = ±15V, RL = 20k, VCM = VOUT = 0V, TA = 25°C, unless otherwise noted. LT1789-1 MIN TYP 60 30 3 0.2 0.012 0.026 460 220 2.7 1 ±0.0001 0.028 MAX MIN LT1789-10 TYP 25 12 1.5 0.066 270 220 2.7 1 ±0.0001 MAX UNITS kHz kHz kHz kHz V/μs μs kΩ μA SR RREFIN IREFIN AVREF Slew Rate Settling Time to 0.01% Reference Input Resistance Reference Input Current Reference Gain to Output 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 CONDITIONS VO = ±10V G=1 G = 10 (Note 2) G = 100 (Note 2) G = 1000 (Note 2) VO = ±10V G=1 G = 10 G = 100 G = 1000 G < 1000 (Notes 2, 3) G = 1000 (Notes 3, 5) G=1 (Notes 3, 5) (Note 3) (Note 3) l l l l l l l l l l l l l l l l l l l LT1789-10 MAX 0.15 0.38 0.38 0.43 25 15 25 120 MIN TYP MAX UNITS % % % % ppm ppm ppm ppm ppm/°C µV µV mV µV µV/°C µV/°C nA pA/°C 45 35 14 –14.8 14 nA pA/°C V MIN TYP 0.20 0.43 0.48 Gain Nonlinearity 45 45 180 5 50 325 8 400 0.3 8 2 30 4 1000 0.8 22 4.5 G/T VOST VOSI VOSIH VOSO VOSOH VOSI/T VOSO/T IOS IOS/T IB IB/T VCM CMRR Gain vs Temperature Input Offset Voltage Input Offset Voltage Hysteresis Output Offset Voltage Output Offset Voltage Hysteresis Input Offset Voltage Drift (RTI) Output Offset Voltage Drift Input Offset Current Input Offset Current Drift Input Bias Current Input Bias Current Drift Input Voltage Range Common Mode Rejection Ratio 5 50 285 Total Input Referred Offset Voltage VOST = VOSI + VOSO/G 8 50 0.2 1.5 2 45 35 –14.8 30 1.2 120 0.7 5 4.5 G = 1, Other Input Grounded 1k Source Imbalance, VCM = –14.8V to 14V G=1 G = 10 G = 100, 1000 l l l l 78 96 100 91 100 dB dB dB 1789fc 7 LT1789-1/LT1789-10 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER PSRR Power Supply Rejection Ratio CONDITIONS LT1789-1, VS = ±1.25V to ±16V LT1789-10, VS = ±1.50V to ±16V G=1 G = 10 G = 100, 1000 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 MIN TYP MAX MIN LT1789-10 TYP MAX UNITS l l l l l l 92 102 104 ±1.25 150 ±14.25 0.010 98 104 ±1.50 150 ±14.25 0.026 dB dB dB V µA V V/µs Minimum Supply Voltage IS VO SR Supply Current Output Voltage Swing Slew Rate VOUT = ±10V l 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 CONDITIONS VO = ±10V G=1 G = 10 (Note 2) G = 100 (Note 2) G = 1000 (Note 2) VO = ±10V G=1 G = 10 G = 100 G = 1000 G < 1000 (Notes 2, 3) G = 1000 (Notes 3, 5) G=1 (Notes 3, 5) (Note 3) (Note 3) l l l l l l l l l l l l l l l l l l l LT1789-10 MAX 0.20 0.57 0.57 0.62 30 20 30 130 MIN TYP MAX UNITS % % % % ppm ppm ppm ppm ppm/°C µV µV mV µV µV/°C µV/°C nA pA/°C 50 35 14 –14.8 14 nA pA/°C V MIN TYP 0.25 0.62 0.67 Gain Nonlinearity 50 50 200 5 50 340 8 400 0.3 8 2 30 4.2 1000 0.8 22 5 G/T VOST VOSI VOSIH VOSO VOSOH VOSI/T VOSO/T IOS IOS/T IB IB/T VCM CMRR Gain vs Temperature Input Offset Voltage Input Offset Voltage Hysteresis Output Offset Voltage Output Offset Voltage Hysteresis Input Offset Voltage Drift (RTI) Output Offset Voltage Drift Input Offset Current Input Offset Current Drift Input Bias Current Input Bias Current Drift Input Voltage Range Common Mode Rejection Ratio 5 50 305 Total Input Referred Offset Voltage VOST = VOSI + VOSO/G 8 50 0.2 1.5 2 50 35 –14.8 30 1.3 120 0.7 5 5 G = 1, Other Input Grounded 1k Source Imbalance, VCM = –14.8V to 14V G=1 G = 10 G = 100, 1000 l l l l 76 94 98 89 98 dB dB dB 1789fc 8 LT1789-1/LT1789-10 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER PSRR Power Supply Rejection Ratio CONDITIONS LT1789-1, VS = ±1.25V to ±16V LT1789-10, VS = ±1.50V to ±16V G=1 G = 10 G = 100, 1000 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 MIN TYP MAX MIN LT1789-10 TYP MAX UNITS l l l l l l 90 100 102 ±1.25 160 ±14.15 0.008 96 102 ±1.50 160 ±14.15 0.024 dB dB dB V µA V V/µs Minimum Supply Voltage IS VO SR Supply Current Output Voltage Swing Slew Rate VOUT = ±10V l 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. 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. TYPICAL PERFORMANCE CHARACTERISTICS Supply Current vs Supply Voltage 120 110 SUPPLY CURRENT (μA) 125°C INPUT BIAS CURRENT (nA) 100 90 80 70 60 50 40 30 20 0 5 10 15 20 25 30 35 TOTAL SUPPLY VOLTAGE (V) 40 –25 –50 –25 50 25 0 75 TEMPERATURE (°C) 25°C –55°C –5 0 (LT1789-1, LT1789-10) Input Bias Current vs Common Mode Input Voltage –10 –12 INPUT BIAS CURRENT (nA) –14 –16 –18 –20 –22 –24 –26 –28 100 125 VS = 5V, 0V VREF = 2.5V 125°C 25°C 85°C –55°C Input Bias Current vs Temperature VS = 5V, 0V VCM = 2.5V –10 –15 –20 –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 1789 G01 1789 G02 1789fc 9 LT1789-1/LT1789-10 TYPICAL PERFORMANCE CHARACTERISTICS Output Voltage Swing vs Load Current 5.0 OUTPUT VOLTAGE SWING—SOURCING (V) 4.8 4.6 4.4 4.2 4.0 VS = 5V, 0V VREF = 2.5V 125°C 25°C 125°C SOURCE 25°C 1.6 1.4 1.2 1.0 0.8 0.6 0.4 SINK –55°C 0.2 0 0.001 0.01 0.1 1 OUTPUT CURRENT (mA) 10 1789 G04 (LT1789-1) Gain vs Frequency –55°C 80 OUTPUT VOLTAGE SWING—SINKING (V) 70 60 50 GAIN (dB) 40 30 20 10 0 –10 –20 100 1k 10k FREQUENCY (Hz) 100k 1789 G05 Slew Rate vs Temperature VS = 5V, 0V VREF = 2.5V 0.050 VS = 5V, 0V 0.045 VREF = 2.5V G=1 0.040 RL = 20k G = 1000 G = 100 SLEW RATE (V/μs) 0.035 RISING 0.030 0.025 0.020 0.015 0.010 –50 –25 0 75 50 25 TEMPERATURE (°C) 100 125 FALLING G = 10 G=1 1789 G06 NEGATIVE POWER SUPPLY REJECTION RATIO (dB) 120 COMMON MODE REJECTION RATIO (dB) 110 100 90 80 70 60 50 40 10 1k 100 FREQUENCY (Hz) G = 10 VS = 5V, 0V VREF = 2.5V 140 120 100 80 60 40 20 0 10 G=1 G = 100 G = 10 G = 1000 POSITIVE POWER SUPPLY REJECTION RATIO (dB) Common Mode Rejection Ratio vs Frequency Negative Power Supply Rejection Ratio vs Frequency VS = 5V, 0V VREF = 2.5V INPUT REFERRED Positive Power Supply Rejection Ratio vs Frequency 140 120 100 80 60 40 20 0 10 100 1k FREQUENCY (Hz) 10k 20k 1789 G09 G = 100, 1000 G = 10 G=1 VS = 5V, 0V VREF = 2.5V INPUT REFERRED G = 100, 1000 G=1 10k 20k 1879 G07 100 1k FREQUENCY (Hz) 10k 20k 1789 G08 Output Impedance vs Frequency 10k VS = 5V, 0V VREF = 2.5V 100 90 80 OVERSHOOT (%) 70 60 50 40 30 20 10 1 100 0 1k 10k FREQUENCY (Hz) 100k 1789 G10 Overshoot vs Capacitive Load VS = 5V, 0V VREF = 2.5V VOUT = 100mVP-P OUTPUT STEP (V) 10 8 6 4 2 0 –2 –4 –6 –8 –10 1000 1789 G11 Settling Time to 0.01% vs Output Step VS = ±15V RL = 20k G=1 OUTPUT IMPEDANCE (Ω) 1k 100 10 AV = 1 AV = 10 AV ≥ 100 1 10 100 CAPACITIVE LOAD (pF) 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 1000 VOLTAGE NOISE DENSITY (nV/√Hz) CURRENT NOISE DENSITY (fA/√Hz) VS = 5V, 0V VREF = 2.5V INPUT REFERRED G=1 1000 (LT1789-1) Current Noise Density vs Frequency VS = 5V, 0V VREF = 2.5V 100 G = 10 100 RS LT1789-1 G = 100, 1000 10 1 10 100 FREQUENCY (Hz) 1k 1789 G13 10 1 10 100 FREQUENCY (Hz) 1k 1789 G14 0.1Hz to 10Hz Noise Voltage, G=1 VS = 5V, 0V VREF = 2.5V NOISE VOLTAGE (0.5μV/DIV) NOISE VOLTAGE (2μV/DIV) 0.1Hz to 10Hz Noise Voltage, RTI, G = 1000 VS = 5V, 0V VREF = 2.5V 0 1 2 3 456 TIME (SEC) 7 8 9 10 1789 G15 0 1 2 3 456 TIME (SEC) 7 8 9 10 1789 G16 0.1Hz to 10Hz Noise Current CHANGE IN OUTPUT VOLTAGE (V) VS = 5V, 0V VREF = 2.5V NOISE CURRENT (5pA/DIV) 1.5 Turn-On Characteristics VS = 5V, 0V VREF = 2.5V VCM = 2.5V G = 1000 TA = 25°C 0.5 –0.5 –1.5 0 1 2 3 456 TIME (SEC) 7 8 9 10 1789 G17 0 10 20 TIME (ms) 30 40 1789 G18 1789fc 11 LT1789-1/LT1789-10 TYPICAL PERFORMANCE CHARACTERISTICS Output Voltage Swing vs Load Current 5.0 OUTPUT VOLTAGE SWING—SOURCING (V) 4.8 4.6 4.4 4.2 4.0 VS = 5V, 0V VREF = 2.5V 125°C 25°C 125°C SOURCE 25°C 1.6 1.4 1.2 1.0 0.8 0.6 0.4 SINK –55°C 0.2 0 0.001 0.01 0.1 1 OUTPUT CURRENT (mA) 10 1789 G21 (LT1789-10) Gain vs Frequency –55°C 80 OUTPUT VOLTAGE SWING—SINKING (V) 70 60 50 GAIN (dB) 40 30 20 10 0 –10 –20 100 1k 10k FREQUENCY (Hz) 100k 1789 G22 Slew Rate vs Temperature VS = 5V, 0V VREF = 2.5V 0.12 0.11 0.10 RISING G = 1000 G = 100 SLEW RATE (V/μs) 0.09 0.08 0.07 0.06 0.05 0.04 –50 –25 0 25 50 75 100 125 FALLING G = 10 TEMPERATURE (°C) 1789 G23 NEGATIVE POWER SUPPLY REJECTION RATIO (dB) 120 COMMON MODE REJECTION RATIO (dB) G = 100, 1000 110 100 90 80 70 60 50 40 10 100 1k FREQUENCY (Hz) G = 10 VS = 5V, 0V VREF = 2.5V 140 120 100 80 G = 10 60 40 20 0 G = 1000 POSITIVE POWER SUPPLY REJECTION RATIO (dB) Common Mode Rejection Ratio vs Frequency Negative Power Supply Rejection Ratio vs Frequency VS = 5V, 0V VREF = 2.5V INPUT REFERRED Positive Power Supply Rejection Ratio vs Frequency 140 120 100 80 60 40 20 0 10 100 1k FREQUENCY (Hz) 10k 20k 1789 G26 G = 100, 1000 G = 10 VS = 5V, 0V VREF = 2.5V INPUT REFERRED G = 100 10k 20k 1789 G24 10 100 1k FREQUENCY (Hz) 10k 20k 1789 G25 Output Impedance vs Frequency 10k VS = 5V, 0V VREF = 2.5V 100 90 80 OVERSHOOT (%) 70 60 50 40 30 20 10 1 100 1k 10k FREQUENCY (Hz) 100k 1789 G27 Overshoot vs Capacitive Load VS = 5V, 0V VREF = 2.5V VOUT = 100mVP-P OUTPUT STEP (V) 10 8 6 4 2 0 –2 –4 –6 –8 1000 1789 G28 Settling Time to 0.01% vs Output Step VS = ±15V RL = 20k G = 10 OUTPUT IMPEDANCE (Ω) 1k 100 10 G = 1000 G = 100 G = 10 100 CAPACITIVE LOAD (pF) 0 10 –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 1000 VOLTAGE NOISE DENSITY (nV/√Hz) CURRENT NOISE DENSITY (fA/√Hz) VS = 5V, 0V VREF = 2.5V INPUT REFERRED G = 10 100 1000 (LT1789-10) Current Noise Density vs Frequency VS = 5V, 0V VREF = 2.5V G = 100 G = 1000 100 RS LT1789-10 10 1 10 100 FREQUENCY (Hz) 1k 1789 G30 10 1 10 100 FREQUENCY (Hz) 1k 1789 G31 0.1Hz to 10Hz Noise Voltage, RTI, G = 10 VS = 5V, 0V VREF = 2.5V NOISE VOLTAGE (0.5μV/DIV) 1 3 NOISE VOLTAGE (2μV/DIV) 0.1Hz to 10Hz Noise Voltage, RTI, G = 1000 VS = 5V, 0V VREF = 2.5V 0 2 456 TIME (SEC) 7 8 9 10 1789 G32 0 1 2 3 456 TIME (SEC) 7 8 9 10 1789 G33 0.1Hz to 10Hz Noise Current CHANGE IN OUTPUT VOLTAGE (V) VS = 5V, 0V VREF = 2.5V NOISE CURRENT (5pA/DIV) 1.5 Turn-On Characteristics VS = 5V, 0V VREF = 2.5V VCM = 2.5V G = 1000 TA = 25°C 0.5 –0.5 –1.5 0 1 2 3 456 TIME (SEC) 7 8 9 10 1789 G34 0 10 20 TIME (ms) 30 40 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 2ms/DIV 1789 G39 Small-Signal Transient Response G=1 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 100μs/DIV 1789 G41 Small-Signal Transient Response G = 100 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 (LT1789-10) Small-Signal Transient Response G = 10 Large-Signal Transient Response G = 1000 5V/DIV 5V/DIV 20mV/DIV VS = ±15V RL = 20k CL = 50pF 500μs/DIV 1789 G44 VS = ±15V RL = 20k CL = 50pF 500μs/DIV 1789 G45 VS = 5V, 0V VREF = 2.5V RL = 20k CL = 50pF 100μs/DIV 1789 G46 Small-Signal Transient Response G = 100 Small-Signal Transient Response G = 1000 20mV/DIV 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 15 G≥2 VALID OUTPUT VOLTAGE (V) 10 5 0 –5 –10 –15 –15 G=1 TA = 25°C VALID OUTPUT VOLTAGE (V) 3.0 2.5 2.0 1.5 1.0 0.5 0 –0.5 –1.0 –1.5 –2.0 10 –5 0 5 –10 INPUT COMMON MODE VOLTAGE (V) 15V 15 –2.5 –2.5 –1.5 1.5 –0.5 0.5 INPUT COMMON MODE VOLTAGE (V) 2.5V 2.5 –1.5 –1.5 0 0.5 1.0 –1.0 –0.5 INPUT COMMON MODE VOLTAGE (V) 1.5V 1.5 AV = 10 AV = 1 AV = 2 (LT1789-1) Valid Output Voltage vs Input Common Mode Voltage VS = ±1.5V 1.5 1.0 0.5 0 –0.5 –1.0 AV = 1 AV = 2 AV = 10 TA = 25°C Valid Output Voltage vs Input Common Mode Voltage VS = ±2.5V TA = 25°C VALID OUTPUT VOLTAGE (V) + VD/2 VD/2 V+ VOUT REF 20K VCM + VD/2 VD/2 V+ VOUT REF 20K VCM + VD/2 VD/2 V+ VOUT REF 20K LT1789-1 VCM LT1789-1 LT1789-1 – V– – V– – V– –15V 1789 G49 –2.5V 1789 G50 –1.5V 1789 G51 Valid Output Voltage vs Input Common Mode Voltage VS = 5V 5 TA = 25°C VALID OUTPUT VOLTAGE (V) 3 Valid Output Voltage vs Input Common Mode Voltage VS = 3V TA = 25°C VALID OUTPUT VOLTAGE (V) 4 2 3 G=1 2 G=2 1 G = 10 G=1 1 G=2 G = 10 0 0 0 1 3 4 2 INPUT COMMON MODE VOLTAGE (V) 5V 5 0 2.0 0.5 1.5 2.5 1.0 INPUT COMMON MODE VOLTAGE (V) 3V 3.0 + VD/2 VD/2 V+ VOUT REF 20K VCM + VD/2 VD/2 V+ VOUT REF 20K LT1789-1 VCM LT1789-1 – V– – V– 1789 G52 1789 G53 1789fc 16 LT1789-1/LT1789-10 TYPICAL PERFORMANCE CHARACTERISTICS Valid Output Voltage vs Input Common Mode Voltage VS = ±15V 15 G = 10 VALID OUTPUT VOLTAGE (V) 10 5 0 –5 –10 –15 –15 G = 100 TA = 25°C VALID OUTPUT VOLTAGE (V) 2.5 2.0 1.5 1.0 0.5 0 –0.5 –1.0 –1.5 –2.0 10 –5 0 5 –10 INPUT COMMON MODE VOLTAGE (V) 15V 15 –2.5 –2.5 –1.5 1.5 –0.5 0 0.5 INPUT COMMON MODE VOLTAGE (V) 2.5V 2.5 –1.5 –1.5 0 0.5 1.0 –1.0 –0.5 INPUT COMMON MODE VOLTAGE (V) 1.5V 1.5 AV = 10 AV = 100 (LT1789-10) Valid Output Voltage vs Input Common Mode Voltage VS = ±1.5V 1.5 1.0 0.5 0 –0.5 –1.0 AV = 10 AV = 100 TA = 25°C Valid Output Voltage vs Input Common Mode Voltage VS = ±2.5V TA = 25°C VALID OUTPUT VOLTAGE (V) + VD/2 VD/2 V+ VOUT REF 20K VCM + VD/2 VD/2 V+ VOUT REF 20K VCM + VD/2 VD/2 V+ VOUT REF 20K LT1789-10 VCM LT1789-10 LT1789-10 – V– – V– – V– –15V 1789 G54 –2.5V 1789 G55 –1.5V 1789 G56 Valid Output Voltage vs Input Common Mode Voltage VS = 5V 5 G = 10 VALID OUTPUT VOLTAGE (V) 4 G = 100 3 TA = 25°C VALID OUTPUT VOLTAGE (V) 3 Valid Output Voltage vs Input Common Mode Voltage VS = 3V TA = 25°C G = 10 G = 100 2 2 1 1 0 0 1 3 4 2 INPUT COMMON MODE VOLTAGE (V) 5V 5 0 0 2.0 0.5 1.5 2.5 1.0 INPUT COMMON MODE VOLTAGE (V) 3V 3.0 + VD/2 VD/2 V+ VOUT REF 20K VCM + VD/2 VD/2 V+ VOUT REF 20K LT1789-10 VCM LT1789-10 – V– – V– 1789 G57 1789 G58 1789fc 17 LT1789-1/LT1789-10 BLOCK DIAGRAM V+ V+ 100k 5.7k +IN 3 RG 1 V– V– VB V+ RG 8 5.7k –IN 2 V+ 100k V+ V– V– VB Figure 1. Block Diagram APPLICATIONS INFORMATION Setting the Gain 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: 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 RG = 200k/(0.1 • G – 1) For the lowest achievable gain, RG may be set to infinity by leaving Pins 1 and 8 open. Input and Output Offset Voltage 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: 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) 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 (RTI) (RTO) 18 + + A3 V– + – A1 R1 R2 110k/10k* 110k/100k* 5 REF – R3 R4 110k/10k* 110k/100k* A2 V+ – 6 OUT 7 V+ *LT1789-1/LT1789-10 V– 4 V– 1789 F01 1789fc LT1789-1/LT1789-10 APPLICATIONS INFORMATION Reference Terminal 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. 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. Input Bias Current Return Path 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. V+ –IN RG 1 LT1880 3 Figure 2. Optional Trimming of Output Offset Voltage THERMOCOUPLE RG LT1789-1/ LT1789-10 MICROPHONE, HYDROPHONE, ETC RG LT1789-1/ LT1789-10 RG 10k 200k 200k CENTER-TAP PROVIDES BIAS CURRENT RETURN 1789 F03 Figure 3. Providing an Input Common Mode Current Path 1789fc – + + ±10mV ADJUSTMENT RANGE – 1 LT1789-1/-10 8 REF 3 +IN 5 – + + – 2 OUTPUT 6 2 100Ω 10k 100Ω 10mV –10mV V– 1789 F02 – + LT1789-1/ LT1789-10 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. 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 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. 20 LT1789-1/LT1789-10 TYPICAL APPLICATIONS Single Supply Positive Integrator VIN 3 8 1 2 LT1789-1 REF VS + 7 R1 6 10k 5 VS 3 + LT1636 1 VOUT + – 4 C1 100μF RESET R2 10Ω 2 – 4 1789 TA02 VS = 2.7V TO 32V TIME CONSTANT = (R1)(C1) = 1 SECOND AS SHOWN Avalanche Photo Diode Module Bias Current Monitor FOR OPTIONAL “ZERO CURRENT” FEEDBACK TO APD BIAS REGULATOR, SEE APPENDIX A, APPLICATION NOTE 92 VOUT = 20V TO 90V TO APD APD HIGH VOLTAGE BIAS INPUT 1k* 1% 1μF 100V 100k* Q1 100k* 1μF 100V 1N4690 5.6V 1M* 0.2μF 5V 5V 1μF 6 20k 2 S2 5 1μF – 10k 30k Q2 MPSA42 20k 12 13 S1 5V 14 0.2μF A1 LT1789-1 + A2 LT1006 + 1M* –3.5V – 20k* –3.5V 200k* OUTPUT 0V TO 1V = 0mA TO 1mA 18 5V S3 3 15 22μF –3.5V TO AMPLIFIERS = 1N4148 = TP0610L 16 0.056μF † FOR MORE INFORMATION REFER TO APPLICATION NOTE 92 17 4 5V 1789 TA05 + * = 0.1% METAL FILM RESISTOR 1μF 100V = TECATE CMC100105MX1825 # CIRCLED NUMBERS = LTC1043 PIN NUMBER + 22μF 1789fc 21 LT1789-1/LT1789-10 PACKAGE DESCRIPTION S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) .189 – .197 (4.801 – 5.004) NOTE 3 8 7 6 5 .050 BSC .045 ±.005 .245 MIN .160 ±.005 .228 – .244 (5.791 – 6.197) .150 – .157 (3.810 – 3.988) NOTE 3 .030 ±.005 TYP RECOMMENDED SOLDER PAD LAYOUT .010 – .020 × 45° (0.254 – 0.508) .008 – .010 (0.203 – 0.254) .016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN 0°– 8° TYP 1 2 3 4 .053 – .069 (1.346 – 1.752) .004 – .010 (0.101 – 0.254) 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) .014 – .019 (0.355 – 0.483) TYP .050 (1.270) BSC SO8 0303 1789fc 22 LT1789-1/LT1789-10 REVISION HISTORY REV C DATE 5/10 DESCRIPTION Updated Input Noise Current Density Spec (Revision history begins at Rev C) PAGE NUMBER 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 VIN 3 8 RG 1 2 + 7 6 R1 1k LT1789-1 REF 5 – 4 IL LOAD IL = AV • VIN/R1 AV = 1 + 200k RG 1789 TA03 10°C to 40°C Thermometer VS+ 4 LT1790 6 –1.25 12 29.4k 1% 3 8 36.5k 0.5% 1 2 THERMISTOR THERMOMETRICS DC95G104V 100k @ 25°C 866k 1% 56.2k 1% LT1789-10 5 VS+ + 7 6 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 – 4 RELATED PARTS PART NUMBER DESCRIPTION LTC1100 LT1101 LT1102 LT1167 LT1168 LTC®1418 LT1460 LT1468 LTC1562 LTC1605 Precision Chopper-Stabilized Instrumentation Amplifier Precision, Micropower, Single Supply Instrumentation Amplifier High Speed, JFET Instrumentation Amplifier COMMENTS Best DC Accuracy Fixed Gain of 10 or 100, IS