ltc2493 Linear Technology Corporation, ltc2493 Datasheet
ltc2493
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ltc2493 Summary of contents
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... The integrated temperature sensor offers 1/30th °C resolution and 2°C absolute accuracy. The LTC2493 allows a wide common mode input range ( combination of single-ended or differential inputs can be selected and the first conversion, after a new channel is selected, is valid ...
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... REF ....................................–0. Digital Input Voltage ......................–0. Digital Output Voltage ...................–0. Operating Temperature Range LTC2493C ................................................ 0°C to 70°C LTC2493I ............................................. –40°C to 85°C Storage Temperature Range ................... –65°C to 150°C orDer inForMaTion LEAD FREE FINISH TAPE AND REEL LTC2493CDE#PBF ...
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... – 2.5V ≤ V ≤ GND ≤ ≤ V REF – 2.5V GND REF + – 2.5V GND (Notes REF LTC2493 The denotes the specifications which ● = 25°C. (Notes MIN TYP MAX ● 1 ● 0.5 2.5 ● ● 0.1 25 ● 0 ...
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... LTC2493 analog inpuT anD reFerence temperature range, otherwise specifications are at T SYMBOL PARAMETER + + IN Absolute/Common Mode IN + (IN Corresponds to the Selected Positive Input Channel) – – IN Absolute/Common Mode IN – (IN Corresponds to the Selected Negative Input Channel) V Input Differential Voltage Range ( Full Scale of the Differential Input (IN ...
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... Note 12: The output noise includes the contribution of the internal calibration operations. Note 13: Guaranteed by design and test correlation. Note 14 Note 15: All values refer to V Note 16: Refer to Applications Information section for Performance vs Data Rate graphs. LTC2493 MIN TYP MAX 2.7 5.5 ● 160 275 ● ...
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... LTC2493 Typical perForMance characTerisTics Integral Nonlinearity ( 5V) CC REF REF 2.5V IN(CM GND O 1 –45°C 25°C 0 85°C –1 –2 –3 –2.5 –2 –1.5 –1 –0.5 0 0.5 1 1.5 2 INPUT VOLTAGE (V) 2493 G01 Total Unadjusted Error ( 5V) CC REF ...
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... REF = 2.5V – REF = GND 0 GND IN(CM 25° GND O 0 –0.1 –0.2 –0.3 4.3 90 2.7 3.1 3.5 3.9 4.7 V (V) CC LTC2493 RMS Noise vs Temperature (T 1 REF 0 GND IN(CM GND O 0.8 0.7 0.6 0.5 0 –45 –30 – TEMPERATURE (°C) 2493 G11 Offset Error vs V IN(CM) 0 ...
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... LTC2493 Typical perForMance characTerisTics On-Chip Oscillator Frequency vs Temperature 310 308 306 304 2.5V REF 302 GND IN(CM GND O 300 –45 –30 – TEMPERATURE (°C) 2493 G19 PSRR vs Frequency 4.1V DC ±1. 2.5V REF – GND – ...
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... IN 196 F = GND 25°C 194 A 192 190 188 186 184 182 180 5 3 – (V) IN(CM) LTC2493 Noise Histogram (2x Speed Mode) 16 RMS = 0.85µV 10,000 CONSECUTIVE AVERAGE = 0.184mV READINGS REF 25° ...
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... LTC2493 Typical perForMance characTerisTics Offset Error (2x Speed Mode) 250 V = 2.5V REF GND IN(CM) 200 F = GND 25°C A 150 100 2.5 3 3 (V) CC 2493 G34 PSRR vs Frequency at V (2x Speed Mode 4.1V DC ±1. REF = 2.5V –20 – REF = GND + IN = GND – ...
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... I SCL (Pin 4): Serial Clock Pin of the I LTC2493 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 the SDA pin on the falling edges of the SCL clock ...
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... LTC2493 FuncTional block DiagraM V CC TEMP SENSOR GND + REF – REF CH0 CH1 CH2 MUX CH3 COM AUTOCALIBRATION AND CONTROL + – DIFFERENTIAL – 3RD ORDER IN ∆Σ MODULATOR DECIMATING FIR ADDRESS INTERNAL OSCILLATOR F O (INT/EXT) 1.7k SDA SCL INTERFACE CA0 CA1 ...
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... The device will not acknowledge an external request dur- ing the conversion state. After a conversion is finished, the device is ready to accept a read/write request. Once the LTC2493 is addressed for a read operation, the device begins outputting the conversion result under the control of the serial clock (SCL). There is no latency in the conver- sion result ...
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... V ). For correct converter operation must be positive (REF > REF REF The LTC2493 differential reference input range is 0. For the simplest operation, REF and REF CC put noise is determined by the thermal noise of the front end circuits and, as such, its value in nanovolts is nearly constant with reference voltage ...
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... The serial clock line, SCL, is always an input to the LTC2493 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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... IN ). The 0V ≤ V < –FS ≤ V < < –FS IN INPUT DATA FORMAT The serial input word to the LTC2493 is 13 bits long and is written into the device input register in two 8-bit words. Bit 31 Bit 30 Bit 29 Bit 28 SIG MSB ...
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... If this bit is set to 0, then the next conversion is performed using the previously selected converter configuration … SIG MSB D31 LSB ACK BY MASTER Figure 3a. Timing Diagram for Reading from the LTC2493 SGL ODD A2 A1 DATA INPUT Figure 3b ...
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... Coupled with an integrated fourth order digital low pass filter, the LTC2493 rejects line frequency noise. In the default mode, the LTC2493 simultaneously rejects 50Hz and 60Hz by at least 87dB. If more rejection is required, the LTC2493 can be configured to reject 50Hz or 60Hz to better than 110dB ...
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... During temperature measurements, the 1x mode is always used independent of the value of SPD. Temperature Sensor The LTC2493 includes an integrated temperature sen- sor. The temperature sensor is selected by setting The ADC internally connects to the temperature sensor and performs a conversion. ...
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... LTC2493s or 2 other LTC24XX delta-sigma I C devices (see Synchronizing Multiple LTC2493s with a Global Address Call section). Operation Sequence The LTC2493 acts as a transmitter or receiver, as shown in Figure 6. The device may be programmed to perform several functions. These include input channel selection, S 7-BIT ADDRESS CONVERSION ...
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... Continuous Read/Write Once the conversion cycle is concluded, the LTC2493 can be written to and then read from using the Repeated Start (Sr) command. Figure 8 shows a cycle which begins with a data Write, a repeated Start, followed by a Read and concluded with a Stop command. The following conversion begins after all 32 bits are read out of the device or after a Stop command ...
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... NAK a global read request. Driving the Input and Reference The input and reference pins of the LTC2493 are connected directly to a switched capacitor network. Depending on the relationship between the differential input voltage and the differential reference voltage, these capacitors are switched between these four pins ...
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... For the case of balanced input impedances, the common mode input current effects are rejected by the large CMRR of the LTC2493, 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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... LTC2493 applicaTions inForMaTion Reference Current Similar to the analog inputs, the LTC2493 samples the + differential reference pins (REF and REF small amounts of charge to and from these pins, thus producing a dynamic reference current. If incomplete set- tling occurs (as a function the reference source resistance and reference bypass capacitance) linearity and gain errors are introduced ...
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... Normal Mode Rejection and Antialiasing One of the advantages delta-sigma ADCs offer over conventional ADCs is on-chip digital filtering. Combined with a large oversample ratio, the LTC2493 significantly simplifies antialiasing filter requirements. Additionally, the input current cancellation feature allows external low pass filtering without degrading the DC performance of the device ...
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... Figures 24 and 25 show measurement results for the rejection of a 7.5V peak-to-peak noise source (150% of full scale) applied to the LTC2493. These curves show that the rejec- tion performance is maintained even in extremely noisy environments. 0 ...
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... IN(P- 7.5V IN(P-P) (150% OF FULL SCALE) 0 12.5 25 37.5 50 62.5 75 87.5 100 112.5 125 137.5 150 162.5 175 187.5 200 INPUT FREQUENCY (Hz) Figure 25. Measure Input Normal Mode Rejection vs Input Frequency with Input Perturbation of 150% (50Hz Notch) LTC2493 MEASURED DATA CALCULATED DATA INPUT FREQUENCY (Hz IN(P- 7.5V IN(P-P) (150% OF FULL SCALE) ...
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... LTC2493 applicaTions inForMaTion Using the 2X speed mode of the LTC2493 alters the rejection characteristics around DC and multiples of f The device bypasses the offset calibration in order to increase the output rate. The resulting rejection plots are shown in Figures 26 and 27. 1x type frequency rejection can be achieved using the 2x mode by performing a run- ning average of the previoius two conversion results (see Figure 28) ...
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... REF RMS 10 90 100 OUTPUT DATA RATE (READINGS/SEC) 2493 F35 Figure 35. Resolution (Noise ≤ 1LSB) RMS vs Output Data Rate and Temperature LTC2493 3500 IN(CM) REF(CM REF 3000 F = EXT CLOCK O 2500 T = 85°C A 2000 1500 T = 25° ...
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... Easy Drive also enables very low power, low bandwidth amplifiers to drive the input to the LTC2493. As shown in Figure 7, CH2 is driven by the LT1494. The LT1494 has excellent DC specs for an amplifier with 1.5µA supply current (the maximum offset voltage is 150µV and the open loop gain is 100,000) ...
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... Plastic DFN (4mm × 3mm) (Reference LTC DWG # 05-08-1708 Rev B) 0.70 ±0.05 3.30 ±0.05 PACKAGE OUTLINE 0.25 ± 0.05 0.50 BSC 3.00 REF 4.00 ±0.10 (2 SIDES 0.05 TYP 3.00 ±0.10 (2 SIDES) 0.75 ±0.05 0.00 – 0.05 LTC2493 R = 0.115 0.40 ± 0.10 TYP 8 14 3.30 ±0.10 1.70 ± 0.10 PIN 1 NOTCH R = 0.20 OR 0.35 × 45° CHAMFER (DE14) DFN 0806 REV 0.25 ± 0.05 0.50 BSC 3.00 REF BOTTOM VIEW— ...
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... Output Rate, 200nV Noise, Simultaneous 50Hz/60Hz Rejection Pin Compatible 16-Bit and 24-Bit Versions Pin Compatible 16-Bit and 24-Bit Versions Pin-Compatible 16-Bit and 24-Bit Versions Pin-Compatible with LTC2493/LTC2489 Pin-Compatible with LTC2487/LTC2493 Pin-Compatible 16-Bit and 24-Bit Versions Pin-Compatible with LTC2498/LTC2449 www.linear.com ● = EXTERNAL OSCILLATOR ...