LTC2497 Linear Technology, LTC2497 Datasheet
LTC2497
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LTC2497 Summary of contents
Page 1
... It automatically rejects line frequencies of 50Hz and 60Hz simultaneously. The LTC2497 allows a wide, common mode input range ( combination of single-ended or differential inputs can be selected and the fi rst conversion, after a new channel is selected, is valid. Access to the multiplexer output enables optional external amplifi ...
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... ADCINN, ADCINP, MUXOUTP MUXOUTN ..............–0. Digital Input Voltage ......................–0. Digital Output Voltage ...................–0. Operating Temperature Range LTC2497C ................................................. 0ºC to 70ºC www.DataSheet4U.com LTC2497I ..............................................–40ºC to 85ºC Storage Temperature Range ....................–65ºC to 150ºC 2 PACKAGE/ORDER INFORMATION ...
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... A CONDITIONS + Voltage – Voltage + – – – – Voltage – Voltage + – – REF ) + Sleep Mode, IN LTC2497 MIN TYP MAX 16 ● ● 0.5 2.5 10 ● 32 0.1 ● 0.6 MIN TYP ● (Note 5) ...
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... LTC2497 ANALOG INPUT AND REFERENCE temperature range, otherwise specifi cations are at T – – Leakage Current DC_LEAK( REF DC Leakage Current DC_LEAK(REF ) – – I REF DC Leakage Current DC_LEAK(REF ) t MUX Break-Before-Make OPEN QIRR MUX Off Isolation INPUTS AND DIGITAL OUTPUTS operating temperature range, otherwise specifi ...
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... Note 13: Guaranteed by design and test correlation. Note 14 capacitance of one bus line in pF (10pF ≤ Note 15: All values refer to V Note 16: Refer to Applications Information section for performance versus data rate graphs. LTC2497 MIN TYP MAX UNITS 10 4000 0.125 100 0 ...
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... LTC2497 TYPICAL PERFORMANCE CHARACTERISTICS Integral Nonlinearity ( 5V) CC REF REF 2.5V IN(CM GND O 1 –45°C 25°C 0 85°C –1 www.DataSheet4U.com –2 –3 –2.5 –2 –1.5 –1 –0.5 0 0.5 1 1.5 INPUT VOLTAGE (V) Total Unadjusted Error ( 5V) CC REF ...
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... GND 306 304 2.5V REF 302 GND IN(CM GND O 300 –45 –30 – TEMPERATURE (°C) 2497 G10 LTC2497 Offset Error 0.3 + REF = 2.5V – REF = GND 0 GND IN(CM 25° GND O 0 –0.1 –0.2 –0 ...
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... LTC2497 TYPICAL PERFORMANCE CHARACTERISTICS PSRR vs Frequency 4. 2.5V REF – GND – GND – GND 25°C A –60 –80 –100 www.DataSheet4U.com –120 –140 10k 1 10 100 1k 100k FREQUENCY AT V (Hz) CC Conversion Current vs Temperature 200 F = GND O SCL = 0 SDA = 1 180 ...
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... All seven pins must be connected to ground for proper operation. SCL (Pin 2): Serial Clock Pin of the I LTC2497 can only act as a slave and the SCL pin only ac- cepts an external serial clock. Data is shifted into the SDA pin on the rising edges of the SCL clock and output through www ...
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... LTC2497 FUNCTIONAL BLOCK DIAGRAM V CC GND + REF – REF CH0 CH1 • • • CH15 COM www.DataSheet4U.com 10 MUXOUTP ADCINP AUTOCALIBRATION + – DIFFERENTIAL MUX 3RD ORDER ∆Σ MODULATOR DECIMATING FIR MUXOUTN ADCINN INTERNAL OSCILLATOR F O (INT/EXT) AND CONTROL SDA 2-WIRE ...
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... The device will not acknowledge an external request dur- ing the conversion state. After a conversion is fi nished, the device is ready to accept a read/write request. Once the LTC2497 is addressed for a read operation, the device begins outputting the conversion result under the control 2 C interface. ...
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... The outputs of the multiplexer (MUXOUTP/MUXOUTN) and the inputs to the ADC (ADCINP/ADCINN) can be used to perform input signal conditioning on any of the selected input channels or simply shorted together for direct digitization external amplifi used, the LTC2497 automatically calibrates both the offset and drift of this – ). ...
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... The serial clock line, SCL, is always an input to the LTC2497 and the serial data line SDA is bidirectional. The device supports the standard mode and the fast mode for data transfer speeds up to 400kbits/s. ...
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... The output register contains the last conversion result. After each conversion is completed, the device automati- cally enters the sleep state where the supply current is reduced to 1µA. When the LTC2497 is addressed for a read operation, it acknowledges (by pulling SDA low) and acts www.DataSheet4U.com as a transmitter ...
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... APPLICATIONS INFORMATION INPUT DATA FORMAT The LTC2497 serial input is 8 bits long and is written into the device in one 8-bit word. SGL, ODD, A2, A1, A0 are used to select the input channel. After power-up, the device initiates an internal reset cycle which sets the input channel to CH0-CH1 (IN – ...
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... LTC2497 APPLICATIONS INFORMATION Table 3. Channel Selection MUX ADDRESS ODD/ SGL SIGN www.DataSheet4U.com – ...
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... LTC2497s or other LTC24XX delta-sigma I chronizing Multiple LTC2497s with Global Address Call section). Operation Sequence The LTC2497 acts as a transmitter or receiver, as shown in Figure 4. The device may be programmed to select an input channel, differential or single-ended mode, and channel polarity. Continuous Read ...
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... LTC2497 APPLICATIONS INFORMATION S 7-BIT ADDRESS CONVERSION SLEEP www.DataSheet4U.com S 7-BIT ADDRESS R ACK CONVERSION SLEEP DATA OUTPUT Figure 5. Consecutive Reading with the Same Input/Confi guration S 7-BIT ADDRESS CONVERSION S 7-BIT ADDRESS CONVERSION Figure 7. Start a New Conversion Without Reading Old Conversion Result 18 R/W ACK DATA DATA INPUT/OUTPUT Figure 4 ...
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... Global read commands are not allowed and the converters will NAK a global read request. Driving the Input and Reference The input and reference pins of the LTC2497 are connected directly to a switched capacitor network. Depending the relationship between the differential input voltage and the differential reference voltage, these capacitors are switched between these four pins ...
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... The inputs (CH0-CH15, COM), on the other hand, are typically driven from larger source resistances. Source resistances up to 10k may interface directly to the LTC2497 and settle completely; however, the addition of external capacitors at the input terminals in order to fi lter unwanted noise (antialiasing) results in incomplete settling ...
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... IN proportionally with input voltage. For the case of balanced input impedances, the common mode input current effects are rejected by the large CMRR of the LTC2497, leading to little degradation in accuracy. Mismatches in source impedances lead to gain errors proportional to the dif- ference between the common mode input and common mode reference ...
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... It operates with supply voltages as low as 2.7V and its noise level is 18nV/√ ⎯ H ⎯ The Easy Drive input technology of the LTC2497 enables an RC network to be added directly to the output of the LTC6078. The capacitor reduces the magnitude of the current spikes seen at the input to the ADC and the resistor isolates the capacitor load from the op-amp output enabling stable operation ...
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... Normal Mode Rejection and Antialiasing One of the advantages delta-sigma ADCs offer over conventional ADCs is on-chip digital fi ltering. Combined with a large oversample ratio, the LTC2497 signifi cantly simplifi es antialiasing fi lter requirements. Additionally, the input current cancellation feature allows external low pass fi ...
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... Figure 19 shows mea- surement results for the rejection of a 7.5V peak-to-peak , where f = 55Hz N N noise source (150% of full scale) applied to the LTC2497. This curve shows that the rejection performance is main- • 256) only reject noise N tained even in extremely noisy environments. Output Data Rate When using its internal oscillator, the LTC2497 produces ...
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... Figure 18. Input Normal Mode Rejection vs Input Frequency with Input Perturbation of 100% (50Hz/60Hz Notch) by the user and can be made insignifi cantly short. When operating with an external conversion clock ( external oscillator), the LTC2497 output data rate can be increased. The duration of the conversion cycle is 41036 307 ...
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... LTC2497 APPLICATIONS INFORMATION IN(CM) REF(CM REF EXT CLOCK 85° 25°C A – www.DataSheet4U.com OUTPUT DATA RATE (READINGS/SEC) Figure 20. Offset Error vs Output Data Rate and Temperature 25°C, 85° ...
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... DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.20mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE LTC2497 0.70 ± 0.05 PACKAGE OUTLINE PIN 1 NOTCH R = 0.30 TYP OR 3.15 ± ...
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... Output Rate, 220nV Noise, Simultaneous 50Hz/60Hz Rejection 8kHz Output Rate, 200nV Noise, Simultaneous 50Hz/60Hz Rejection Pin Compatible with 16-Bit and 24-Bit Versions Pin Compatible with 16-Bit and 24-Bit Versions Pin-Compatible with LTC2498/LTC2449 Pin-Compatible with LTC2496/LTC2449 Pin-Compatible with LTC2497 www.linear.com ● ∆Σ ADC SDA WITH ...