LT1997-2 Precision, Wide Voltage Range, Gain Selectable Funnel Amplifier FEATURES DESCRIPTION n Precision Attenuation: Gain = 0.1, 0.2, 0.25 The LT 1997-2 is an attenuating (funnel) difference ampli- n 255V Common Mode Voltage Range fier that can be used to translate large differential signals to n 105dB Minimum CMRR (Gain = 0.1) the low voltage range compatible with ADCs. It combines n 0.006% (60ppm) Maximum Gain Error a precision operational amplifier with highly-matched re- n 1ppm/C Maximum Gain Error Drift sistors to form a one-chip solution to attenuate and level n 2ppm Maximum Gain Nonlinearity shift voltages accurately using no external components. n Wide Supply Voltage Range: 3.3V to 50V It comes with three standard pin-selectable gain options n Rail-to-Rail Output (0.1, 0.2 and 0.25), which can be further combined to n 350A Supply Current form gains from 0.0455 to 0.55 (attenuations of 1.82 to n 80V Maximum Op Amp Offset Voltage 22) with accuracy of 0.006% (60ppm). The LT1997-2 also n 1MHz 3dB Bandwidth (Gain=0.1) works across a very wide input common-mode voltage n Low Power Shutdown: 20A range (255V), enabling robust operation in demanding n Space-Saving MSOP and DFN Packages industrial environments. Its excellent resistor matching results in a common mode rejection ratio of greater than 105dB. APPLICATIONS The resistors maintain their excellent matching over n High Voltage to Low Voltage Level Translation temperature the matching temperature coefficient is n ADC Driver guaranteed less than 1ppm/C. The resistors are extremely n Bidirectional Wide Common Mode Range Voltage linear with voltage, resulting in a gain nonlinearity of less and Current Sensing than 2ppm. n Industrial Data-Acquisition Front-Ends n The LT1997-2 is fully specified at 5V and 15V supplies Replacement for Isolation Circuits n and from 40C to 125C. The device is available in space Differential to Single-Ended Conversion saving 16-lead MSOP and 4mm 4mm DFN14 packages. All registered trademarks and trademarks are the property of their respective owners. TYPICAL APPLICATION Interfacing a 20V Ground-Referenced Input Signal to a 5V ADC P-P LT1997-2 Driving LTC2364-16, +10V ADC, f = 1kHz, 32768-Point FFT IN 5V 0 V = 5V + S 10V INA INB INC V LT1997-2 V = 4V OUT P-P 20 HD2 = 104.3dBc 100k HD3 = 104.4dBc SFDR = 104.3dB 40 125k 25k 4.5V THD = 101dB 2.5V 1.8V TO 5V SNR = 91.8dB 60 250k SINAD = 89.5dB 0.5V V 0V 200 DD DD OUT + IN 80 250k + LTC2364-16 8nF 100 125k 50k REF2 IN REF GND 120 100k 50k REF1 5V 140 0 25 50 75 100 125 47F +INA +INB +INC SHDN V 5.5V TO 40V IN OUT FREQUENCY (kHz) LT6657-5 19972 TA01b GND 19972 TA01a Rev 0 1 Document Feedback For more information www.analog.com AMPLITUDE (dBFS)LT1997-2 ABSOLUTE MAXIMUM RATINGS (Note 1) + Temperature Range (Notes 4, 5) Supply Voltages (V to V ) ........................................60V LT1997I-2.................................................40 to 85C +INA, INA, +INB, INB, LT1997H-2 ............................................. 40 to 125C +INC, INC (Note 2) .........................................V 270V Maximum Junction Temperature .......................... 150C REF, REF1, REF2..................... (V + 60V) to (V 0.3V) + Storage Temperature Range ......................65 to 150C SHDN ..................................... (V + 0.3V) to (V 0.3V) MSOP Lead Temperature (Soldering, 10 sec) ........300C Output Current (Continuous) (Note 6) ....................50mA Output Short-Circuit Duration (Note 3) ..........................................Thermally Limited PIN CONFIGURATION TOP VIEW TOP VIEW +INA 1 14 INA +INA 1 16 INA +INB 3 14 INB +INB 3 12 INB 15 +INC 5 12 INC NC 4 11 NC V + REF1 6 11 V +INC 5 10 INC REF2 7 10 SHDN V 8 9 OUT + SHDN 6 9 V MS PACKAGE REF 7 8 OUT VARIATION: MS16 (12) 16-LEAD PLASTIC MSOP T = 150C, = 130C/W JMAX JA DF PACKAGE 14(12)-LEAD (4mm 4mm) PLASTIC DFN T = 150C, = 45C/W , = 3C/W JMAX JA JC EXPOSED PAD (PIN 15) IS V , MUST BE SOLDERED TO PCB ORDER INFORMATION SPECIFIED LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT1997IDF-2 PBF LT1997IDF-2 TRPBF 19972 14-Lead (4mm 4mm) Plastic DFN 40C to 85C LT1997HDF-2 PBF LT1997HDF-2 TRPBF 19972 14-Lead (4mm 4mm) Plastic DFN 40C to 125C LT1997IMS-2 PBF LT1997IMS-2 TRPBF 19972 16-Lead Plastic MSOP 40C to 85C LT1997HMS-2 PBF LT1997HMS-2 TRPBF 19972 16-Lead Plastic MSOP 40C to 125C *The temperature grade is identified by a label on the shipping container. Consult ADI Marketing for parts specified with wider operating temperature ranges. Parts ending with PBF are RoHS and WEEE compliant. Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with TRMPBF suffix. Rev 0 2 For more information www.analog.com