ltc2435-1 Linear Technology Corporation, ltc2435-1 Datasheet
ltc2435-1
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ltc2435-1 Summary of contents
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... The LTC2435-1 can be con- figured for better than 87dB input differential mode rejec- tion over the range of 49Hz to 61.2Hz (50Hz and 60Hz ± ...
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... GND .................................... – 0. Digital Input Voltage to GND ........ – 0. Digital Output Voltage to GND ..... – 0. Operating Temperature Range LTC2435C/LTC2435-1C ........................... 0°C to 70°C LTC2435I/LTC2435-1I ........................ – 40°C to 85°C Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300° ORDER I FOR ATIO ...
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... Input Normal Mode Rejection (Notes 5, 8) 50Hz ±2% (LTC2435) 2.5V ≤ REF Input Common Mode Rejection GND ≤ IN 49Hz to 61.2Hz (LTC2435-1) Input Normal Mode Rejection F = GND (Note 5) O 49Hz to 61.2Hz (LTC2435-1) Input Normal Mode Rejection External Oscillator (Note 5) /2560 ± ...
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... LTC2435/LTC2435 DIGITAL I PUTS A D DIGITAL OUTPUTS operating temperature range, otherwise specifications are at T SYMBOL PARAMETER V High Level Input Voltage IH CS Low Level Input Voltage IL CS High Level Input Voltage IH SCK V Low Level Input Voltage IL SCK I Digital Input Current ...
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... O External Oscillator (Note 11) Internal Oscillator (Note 10), LTC2435 Internal Oscillator (Note 10), LTC2435-1 External Oscillator (Notes 10, 11) (Note 10) (Note 9) (Note 9) (Note 9) Internal Oscillator (Notes 10, 12), LTC2435-1 External Oscillator (Notes 10, 11) (Note 10) (Note 9) (Note 5) Note (external oscillator). Note 9: The converter is in external SCK mode of operation such that the SCK pin is used as digital input ...
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... LTC2435/LTC2435 TYPICAL PERFOR A CE CHARACTERISTICS Total Unadjusted Error ( 5V) REF –340 F = GND REF T = –45° 2.5V A INCM INCM –345 T = 25°C A –350 T = 85°C A –355 –360 –2.5 –1.5 0.5 1.5 –0.5 INPUT VOLTAGE (V) 2435 G01 Integral Nonlinearity (V = 5V, ...
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... CC – –322 REF = GND –324 V = GND INCM F = GND –326 25°C A –328 –330 –332 –334 –336 –338 –340 2.7 3.1 3.9 4.7 3.5 4.3 V (V) CC LTC2435/LTC2435-1 RMS Noise vs Temperature (T 5 GND O 4 REF 4 GND 4.4 INCM 4.2 4.0 3.8 3.6 3.4 3.2 3.0 6 –50 – TEMPERATURE (°C) 2435 G11 ...
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... REF – REF = GND V = 0.5V INCM REF GND 25° –5 2.7 3.1 3.9 4.7 5.1 5.5 3.5 4.3 V (V) CC 2435 G21 PSRR vs Frequency (LTC2435-1) 0 ±0. 4. REF = 2.5V –20 – REF = GND + IN = GND – – GND F = GND 25°C A –60 –80 –100 –120 –140 13850 13900 ...
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... GND F = EXT OSC 25°C A RES = LOG (V /NOISE ) 2 REF RMS 100 120 140 160 180 200 OUTPUT DATA RATE (READINGS/SEC) LTC2435/LTC2435-1 Sleep-Mode Current vs Temperature –45 –30 – TEMPERATURE (°C) 2435 G29 ≤ ...
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... When the F connected to GND (F oscillator and the digital filter first null is located at 60Hz (LTC2435) or simultaneous 50Hz/60Hz (LTC2435-1). When F O frequency f system clock and the digital filter first null is located at a ...
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... TEST CIRCUITS SDO 1.69k C LOAD Hi Hi ∫ ∑ ADC Figure 1. Functional Block Diagram = 20pF 2435 TA03 LTC2435/LTC2435-1 INTERNAL OSCILLATOR AUTOCALIBRATION AND CONTROL (INT/EXT) SERIAL INTERFACE DECIMATING FIR V CC 1.69k SDO C = 20pF LOAD Hi ...
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... Clocked by the on-chip oscillator, the LTC2435 achieves a minimum of 110dB rejection at the line frequency (50Hz or 60Hz ±2%), while the LTC2435-1 achieves a minimum of 87db rejection at 50Hz ±2% and 60Hz ±2% simultaneously. Ease of Use The LTC2435/LTC2435-1 data output has no latency, filter settling delay or redundant data associated with the conversion cycle ...
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... The advantage of continuous calibration is extreme stability of full-scale readings with respect to time, supply voltage change and temperature drift. Unlike the LTC2430, the LTC2435 and LTC2435-1 do not perform an offset calibration every conversion cycle. This enables the LTC2435/LTC2435-1 to double their output rate while maintaining line frequency rejection. The initial ...
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... U APPLICATIO S I FOR ATIO Output Data Format The LTC2435/LTC2435-1 serial output data stream is 24 bits long. The first 3 bits represent status information indicating the sign and conversion state. The next 21 bits are the conversion result, MSB first. The third and fourth bit together are also used to indicate an underrange condition (the differential input voltage is below – ...
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... First, the variation with respect to supply voltage is linear. Second, the magnitude of the offset error decreases with de- creased supply voltage. Third, the offset error in micro- volts is almost independent with reference and therefore Table 2. LTC2435/LTC2435-1 Output Data Format Differential Input Voltage ≥ ...
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... HEO LEO the range 49Hz to 61.2Hz is required or when the converter must be synchronized with an outside source, the LTC2435-1 can operate with an external conversion clock. The performance of the LTC2435-1 is the same as the /2560 EOSC LTC2435 when driven by an external conversion clock at the F pin. ...
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... INPUT FREQUENCY DEVIATION FROM NOTCH FREQUENCY (%) 2435 F07a Figure 7a. LTC2435/LTC2435-1 Normal Mode Rejection When Using an External Oscillator of Frequency f without Running Averages EOSC Table 3a. LTC2435 State Duration State Operating Mode CONVERT Internal Oscillator F = LOW, (60Hz Rejection) ...
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... SDO pin on the falling edge of the serial clock. In the Internal SCK mode of operation, the SCK pin is an output and the LTC2435/LTC2435-1 create their own se- rial clock by dividing the internal conversion clock the External SCK mode of operation, the SCK pin is used as input ...
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... BIT 21 BIT 20 BIT 19 BIT 18 EOC SIG MSB DATA OUTPUT Figure 8. External Serial Clock, Single Cycle Operation LTC2435/LTC2435 50Hz REJECTION (LTC2435) = EXTERNAL OSCILLATOR = 60Hz REJECTION (LTC2435) = 50Hz/60Hz REJECTION (LTC2435-1) 3-WIRE SPI INTERFACE TEST EOC BIT 5 BIT 0 LSB Hi-Z CONVERSION 2435 F08 24351fb 19 ...
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... Once CS is pulled LOW, SCK goes LOW and EOC is output to the SDO pin. EOC = 1 while a conversion is in progress and EOC = 0 if the conversion is over 50Hz REJECTION (LTC2435) = EXTERNAL OSCILLATOR = 60Hz REJECTION (LTC2435) = 50Hz/60Hz REJECTION (LTC2435-1) 3-WIRE SPI INTERFACE TEST EOC BIT 19 BIT 9 BIT 8 MSB ...
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... BIT 20 BIT 19 BIT 18 SIG MSB DATA OUTPUT Figure 11. Internal Serial Clock, Single Cycle Operation LTC2435/LTC2435-1 after EOC goes EOCtest is 23μs (LTC2435), 26μs (LTC2435-1) if EOCtest = logic LOW 50Hz REJECTION (LTC2435) = EXTERNAL OSCILLATOR = 60Hz REJECTION (LTC2435) = 50Hz/60Hz REJECTION (LTC2435-1) 2-WIRE ...
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... CS. This can be avoided by adding an external 10k pull-up resistor to the SCK pin or by never pulling CS HIGH when SCK is LOW. Whenever SCK is LOW, the LTC2435/LTC2435-1 internal pull-up at pin SCK is disabled. Normally, SCK is not externally driven if the device is in the internal SCK timing mode ...
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... GND BIT 21 BIT 20 BIT 19 BIT 18 SIG MSB DATA OUTPUT Figure 13. Internal Serial Clock, Continuous Operation LTC2435/LTC2435-1 exceeds 2.2V. An internal 50Hz REJECTION (LTC2435) = EXTERNAL OSCILLATOR = 60Hz REJECTION (LTC2435) = 50Hz/60Hz REJECTION (LTC2435-1) 2-WIRE INTERFACE BIT 5 BIT 0 LSB CONVERSION 23 2435 F13 24351fb ...
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... CC During the conversion period, the undershoot and/or overshoot of a fast digital signal connected to the LTC2435/ LTC2435-1 pins may severely disturb the analog to digital conversion process. Undershoot and overshoot can oc- cur because of the impedance mismatch at the converter pin when the transition time of an external control signal is less than twice the propagation delay from the driver to LTC2435/LTC2435-1 ...
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... When F O typical differential input resistance is 22MΩ (LTC2435) or 24MΩ (LTC2435-1) which will generate a +FS gain error of approximately 0.023ppm (LTC2435) or 0.021ppm (LTC2435-1) for each ohm of source resistance driving + IN ...
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... LEAK ( – REF R (TYP LEAK (F 20k f V – SW REF I LEAK Figure 14. LTC2435/LTC2435-1 Equivalent Analog Input Circuit 0pF 0.01μF –10 IN –20 – 0.001μF IN –40 – 100pF CC IN – REF – ...
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... 400 800 1200 1600 R (Ω) SOURCE Figure 19. –FS Error vs R SOURCE + – (Large LTC2435/LTC2435-1 –6 • f ppm. Figure 20 EOSC + – and IN pins when large C values are IN –310 A: ΔR E: Δ –200Ω ΔR F: ΔR = 500Ω ...
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... REF – transferring For the LTC2435-1, the typical differential reference resis- tance is 17.1MΩ which will generate a +FS gain error of approximately 0.029ppm for each ohm of source resis- tance driving REF ...
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... HIGH (internal oscillator and 50Hz notch), every O 100Ω of source resistance driving REF into about 0.092ppm additional INL error; and for the LTC2435-1 operating with simultaneous 50Hz/60Hz re- jection, every 100Ω of source resistance leads to an additional 0.10ppm of additional INL error. When F driven by an external oscillator with a frequency f every 100Ω ...
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... When operated with an external conversion clock (F connected to an external oscillator), the LTC2435/ O LTC2435-1 output data rate can be increased as desired. The duration of the conversion phase is 10278 153600Hz, the converter behaves as if the internal EOSC oscillator is used and the notch is set at 60Hz ...
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... Figure 32. Resolution (Noise vs Output Data Rate and Reference Voltage 25° 85°C A 2435 F28 2435 F30 ≤ 1LSB REF 2.5V REF 2435 F32 ≤ 1LSB) RMS LTC2435/LTC2435 25° 85° REF INCM REFCM ...
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... U Through F 110dB input differential mode rejection at 50Hz or 60Hz ±2%. While for the LTC2435-1, it has a notch frequency of about 55Hz with better than 70db rejection over 48Hz to 62.4Hz, which covers both 50Hz ±2% and 60Hz ±2%. In order to achieve better rejection over the range of 48Hz to 62 ...
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... With a reference voltage V REF LTC2435-1 have a full-scale differential input range of 5V peak-to-peak. Figure 40 shows measurement results for the LTC2435-1 normal mode rejection ratio with a 7.5V peak-to-peak (150% of full scale) input signal superim- 0 –20 –40 – ...
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... APPLICATIO S I FOR ATIO 0 MEASURED DATA CALCULATED DATA –20 –40 –60 –80 –100 –120 150 175 200 100 125 INPUT FREQUENCY (Hz) Figure 38. Input Normal Mode Rejection vs Input Frequency (LTC2435- REF – REF = GND V = 2.5V INCM ...
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... Figure 41. Use a Differential Multiplexer to Expand Channel Capability SCK LTC2435/ SDO LTC2435-1 CS Figure 42. Connecting the LTC2435/LTC2435 PIC16F73 MCU Using the SPI Serial Interface W U The listing in Figure data collection program for the LTC2435/LTC2435-1 using the PIC16F73 microcontroller. The microcontroller is configured to transfer data through the SPI serial interface ...
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... LTC2435/LTC2435 APPLICATIO S I FOR ATIO // Basic data collection program for the LTC2435 using the // PIC16F73 microcontroller. Collects data as fast as possible // and sends it out the serial port at 57600 baud as six // hexadecimal characters, followed by a carriage return. // This can be captured with a terminal program and analyzed // with a spreadsheet using the HEX2DEC function (in Excel ...
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... Conversion actually started after last data byte was read, // but raising CS_ ensures the loop will never lock up waiting for // a low on SDO if a clock pulse is missed for some reason Figure 43. A Sample Program for Data Collection from the LTC2435/LTC2435-1 Using the PIC16F73 Microcontroller LTC2435/LTC2435-1 37 24351fb ...
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... The LTC2435/LTC2435-1 have the virtue of being able to digitize an input voltage that is outside the range defined by the reference, thereby providing a simple means to implement a ratiometric example of correlated double sampling. This circuit uses a bipolar amplifier (LT1219— ...
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... TYP .008 – .012 (0.203 – 0.305) TYP LTC2435/LTC2435-1 .189 – .196* (4.801 – 4.978) .009 (0.229 REF .150 – .157** (3.810 – 3.988) ...
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... Noise, 4ppm INL, 10ppm Total Unadjusted Error, 200μA 800nV 1.45μV Simultaneous 50Hz/60Hz Rejection (LTC2411-1) Simultaneous 50Hz/60Hz Rejection, 800nV Pin Compatible with the LTC2435/LTC2435-1 0.2ppm Noise, 2ppm INL, 3ppm Total Unadjusted Errors 200μA 1.2ppm Noise, 8ppm INL, Pin Compatible with LTC2400 2.8μV Noise, SSOP-16/MSOP Package www.linear.com ● ...