LTC2420IS8 Linear Technology, LTC2420IS8 Datasheet

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... The LTC2420 communicates through a flexible 3-wire digital interface which is compatible with SPI and MICROWIRE , LTC and LT are registered trademarks of Linear Technology Corporation. No Latency is a trademark of Linear Technology Corporation. MICROWIRE is a trademark of National Semiconductor Corporation. V ...

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... REF O V REF CC V REF CC < 5V, 100 Samples/Second 2.048MHz REF O V REF CC = 2.048MHz 0V, (Notes 7, 15 0V, (Notes 8, 15 INFORMATION ORDER PART NUMBER TOP VIEW LTC2420CS8 LTC2420IS8 7 SCK SDO PART MARKING S8 PACKAGE 2420 2420I = 125 C, = 130 C/W JA MIN TYP MAX 250 0 0. 0.04 ...

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ALOG I PUT A D REFERE CE temperature range, otherwise specifications are at T SYMBOL PARAMETER V Input Voltage Range IN V Reference Voltage Range REF C Input Sampling Capacitance S(IN) C Reference Sampling Capacitance S(REF) ...

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LTC2420 CHARACTERISTICS range, otherwise specifications are at T SYMBOL PARAMETER f External Oscillator Frequency Range EOSC t External Oscillator High Period HEO t External Oscillator Low Period LEO t Conversion Time CONV f Internal SCK ...

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W U TYPICAL PERFOR A CE CHARACTERISTICS Total Unadjusted Error (3V Supply 2.5V REF –2 – –55 C, – –6 ...

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LTC2420 W U TYPICAL PERFOR A CE CHARACTERISTICS RMS Noise vs Reference Voltage REFERENCE VOLTAGE (V) 2420 G10 ...

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W U TYPICAL PERFOR A CE CHARACTERISTICS Conversion Current vs Temperature 230 220 V = 5.5V CC 210 200 V = 4.1V CC 190 180 V = 2.7V CC 170 160 150 – 55 –30 – ...

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LTC2420 W U TYPICAL PERFOR A CE CHARACTERISTICS INL vs Output Rate REF F = EXTERNAL – ...

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CTIO AL BLOCK DIAGRA V CC GND REF DAC TEST CIRCUITS SDO 3. ADC C = 20pF LOAD 2420 TC01 ...

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LTC2420 U U APPLICATIO S I FOR ATIO The LTC2420 is pin compatible with the LTC2400. The two devices are designed to allow the user to incorporate either device in the same design with no modifications. While the LTC2420 output ...

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U U APPLICATIO S I FOR ATIO not disturb the cyclic operation described above. These modes of operation are described in detail in the Serial Interface Timing Modes section. Conversion Clock A major advantage delta-sigma converters offer over conventional type ...

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LTC2420 U U APPLICATIO S I FOR ATIO fault current, a resistor 25k may be added in series with the V pin without affecting the performance of the IN device. In the physical layout important ...

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U U APPLICATIO S I FOR ATIO the rising edge of the 24th SCK pulse. On the falling edge of the 24th SCK pulse, SDO goes HIGH indicating a new conversion cycle has been initiated. This bit serves as EOC ...

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LTC2420 U U APPLICATIO S I FOR ATIO –60 –70 –80 –90 –100 –110 –120 –130 –140 –12 –8 – INPUT FREQUENCY DEVIATION FROM NOTCH FREQUENCY (%) Figure 5. LTC2420 Normal Mode Rejection When Using an External Oscillator ...

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U U APPLICATIO S I FOR ATIO Serial Data Output (SDO) The serial data output pin, SDO (Pin 6), drives the serial data during the data output state. In addition, the SDO pin is used as an end of conversion ...

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LTC2420 U U APPLICATIO S I FOR ATIO CS TEST EOC TEST EOC SDO Hi-Z Hi-Z SCK (EXTERNAL) CONVERSION SLEEP external circuitry to latch the output on the rising edge of SCK. EOC can be latched on the first rising ...

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U U APPLICATIO S I FOR ATIO CS TEST EOC BIT 0 SDO EOC Hi-Z SCK (EXTERNAL) SLEEP CONVERSION DATA OUTPUT Figure 7. External Serial Clock, Reduced Data Output Length CS SDO SCK (EXTERNAL) CONVERSION SLEEP W U 2.7V TO ...

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LTC2420 U U APPLICATIO S I FOR ATIO into an internal static shift register. The device remains in the sleep state until the first rising edge of SCK. Data is shifted out the SDO pin on each falling edge of ...

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U U APPLICATIO S I FOR ATIO conversion result into external circuitry. EOC can be latched on the first rising edge of SCK and the last bit of the conversion result on the 24th rising edge of SCK. After the ...

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LTC2420 U U APPLICATIO S I FOR ATIO Internal Serial Clock, 2-Wire I/O, Continuous Conversion This timing mode uses a 2-wire, all output (SCK and SDO) interface. The conversion result is shifted out of the device by an internally generated ...

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U U APPLICATIO S I FOR ATIO capacitor tied to CS, see Figure 12. The time the converter spends in the sleep state is determined by the value of the external timing capacitor, see Figures 13 and 14. Once the ...

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LTC2420 U U APPLICATIO S I FOR ATIO 100 0 1000 CAPACITANCE ON CS (pF) Figure 14. CS Capacitance vs Output Rate 300 250 ...

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U U APPLICATIO S I FOR ATIO propagation delay from the driver to LTC2420. For refer- ence regular FR-4 board, signal propagation veloc- ity is approximately 183ps/inch for internal traces and 170ps/inch for surface traces. Thus, a driver ...

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LTC2420 U U APPLICATIO S I FOR ATIO REF 0pF 100pF 1000pF IN ...

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U U APPLICATIO S I FOR ATIO VREF VREF VREF C = 0.1 F VREF VREF C = 0.001 F VREF ...

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LTC2420 U U APPLICATIO S I FOR ATIO 0 –20 –40 –60 –80 –100 –120 –140 INPUT FREQUENCY 4 Figure 27. Sinc Filter Rejection As a result of the oversampling ratio (256) and the digital filter, ...

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U U APPLICATIO S I FOR ATIO –5 –10 –15 –20 –25 –30 –35 –40 0 INPUT VOLTAGE (V) Figure 31. Total Unadjusted Error at 100 Samples/Second (No Averaging) After acquiring 100 samples/second data the F be ...

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LTC2420 U U APPLICATIO S I FOR ATIO 0.20 500ms 0.15 0.10 0.05 0 –0.05 –0.10 –0.15 –0.20 TIME 33a. Digitized Waveform 2. 300mV + P-P 2.15 2.10 2.05 2.00 1.95 1.90 1.85 1.80 TIME ...

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U TYPICAL APPLICATIO S SYNCHRONIZATION OF MULTIPLE LTC2420s Since the LTC2420’s absolute accuracy (total unadjusted error) is 10ppm, applications utilizing multiple matched ADCs are possible. Simultaneous Sampling with Two LTC2420s One such application is synchronizing multiple LTC2420s, see Figure 35. ...

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LTC2420 U TYPICAL APPLICATIO S LTC2420 # SCK REF V SDO IN GND CS CONTROLLER SCK SDO CS1 CS2 CS3 CS4 CS1 CS2 CS3 CS4 23 OR LESS CLOCK PULSES SCK SDO 30 LTC2420 LTC2420 ...

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U TYPICAL APPLICATIO S Single-Chip Instrumentation Amplifier for the LTC2420 The circuit in Figure simple solution for processing differential signals in pressure transducer, weigh scale or strain gauge applications that can operate on a supply voltage range ...

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LTC2420 U TYPICAL APPLICATIO S Table 5. Typical Performance of the LTC2420 ADC When Used with the LT1920 Instrumentation Amplifiers in Figure 34’s Differential Digitizing Circuit PARAMETER Differential Input Voltage Range Zero Error Maximum Input Current Nonlinearity Noise (Without Averaging) ...

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U TYPICAL APPLICATIO S Using a Low Power Precision Reference The circuit in Figure 38 shows the connections and by- passing for an LT1461-2 2.5V reference. The LT1461 is a bandgap reference capable of 3ppm/ C tem- perature ...

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LTC2420 U TYPICAL APPLICATIO S 2.048MHz Oscillator for 100sps Output Ratio The oscillator circuit shown in Figure 40 can be used to drive the F pin, boosting the conversion rate of the O LTC2420 for applications that do not require ...

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... FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 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 represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. ...

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... V Noise, Fully Differential, 10-Lead MSOP Package Simultaneous 50Hz to 60Hz Rejection 0.16ppm Noise ADCs 8ppm INL, 1.2ppm Noise, Fast Mode REF LTC2420 OUT V SCK IN SDO GND CS 2420 F41 GND Noise P-P 2420f LT/LCG 1000 4K • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 2000 ...