Datasheet LT1997-2 (Analog Devices)

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 350µA Supply Current form gains from 0.0455 to 0.55 (attenuations of 1.82 to n 80µV 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: 20µA 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 Replacement for Isolation Circuits The LT1997-2 is fully specified at 5V and ±15V supplies n Differential to Single-Ended Conversion and from –40°C to 125°C. The device is available in space All registered trademarks and trademarks are the property of their respective owners. saving 16-lead MSOP and 4mm × 4mm DFN14 packages.
TYPICAL APPLICATION Interfacing a 20VP-P Ground-Referenced Input Signal to a 5V ADC LT1997-2 Driving LTC2364-16,
+10V
ADC, fIN = 1kHz, 32768-Point FFT
5V 0 –10V V –INA –INB –INC V+ LT1997-2 S = 5V VOUT = 4VP-P –20 100k HD2 = –104.3dBc HD3 = –104.4dBc 125k 25k –40 SFDR = 104.3dB 4.5V THD = –101dB 2.5V 1.8V TO 5V SNR = 91.8dB 250k – –60 SINAD = 89.5dB 0.5V V 0V OUT 200Ω DD DD IN+ 250k + –80 8nF LTC2364-16 AMPLITUDE (dBFS) 125k 50k –100 REF2 IN– 100k 50k REF1 REF GND –120 5V –140 0 25 50 75 100 125 +INA +INB +INC SHDN V– IN OUT 47µF 5.5V TO 40V FREQUENCY (kHz) LT6657-5 19972 TA01b GND 19972 TA01a Rev 0 Document Feedback For more information www.analog.com 1 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION ELECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS PIN FUNCTIONS BLOCK DIAGRAM APPLICATIONS INFORMATION TYPICAL APPLICATIONS PACKAGE DESCRIPTION TYPICAL APPLICATION RELATED PARTS