LTC2494CUHF#PBF Linear Technology, LTC2494CUHF#PBF Datasheet
LTC2494CUHF#PBF
Specifications of LTC2494CUHF#PBF
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LTC2494CUHF#PBF Summary of contents
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... L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and No Latency ∆∑ and Easy Drive are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. 2.7V TO 5.5V 0.1µ ...
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... LTC2494I .............................................–40°C to 85°C Storage Temperature Range .................. –65°C to 150°C orDer inForMation LEAD FREE FINISH TAPE AND REEL LTC2494CUHF#PBF LTC2494CUHF#TRPBF LTC2494IUHF#PBF LTC2494IUHF#TRPBF Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. ...
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T PARAMETER CONDITIONS Resolution (No Missing Codes) 0.1V ≤ V Integral Nonlinearity 5V ≤ V 2.7V ≤ V Offset Error 2.5V ≤ V Offset Error ...
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LTC2494 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 ...
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Digital inputs anD Digital outputs full operating temperature 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 for 1x Speed ...
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LTC2494 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 ...
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RMS Noise vs Input Differential Voltage 1 REF 0 2.5V IN(CM 25°C A 0.8 0.7 0.6 0.5 0.4 –2.5 –2 –1.5 –1 –0.5 0 0.5 1 ...
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LTC2494 typical perForMance characteristics On-Chip Oscillator Frequency vs Temperature 310 308 306 304 2.5V REF 302 GND IN(CM GND O 300 30 –45 –30 –15 0 ...
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Integral Nonlinearity (2x Speed Mode 5V 2.5V) CC REF 2.5V REF 1.25V IN(CM GND O 1 85°C 0 –45°C, 25°C –1 ...
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LTC2494 typical perForMance characteristics PSRR vs Frequency at V (2x Speed Mode 4.1V DC ±1. REF = 2.5V –20 – REF = GND + IN = GND – – GND f = GND ...
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Functions SDI (Pin 34): Serial Data Input. This pin is used to select the gain, line frequency rejection mode speed mode, temperature sensor, as well as the input channel. The serial data input is applied under ...
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LTC2494 Functional block DiagraM TEMP V SENSOR CC GND + REF – REF CH0 CH1 • • MUX • CH15 COM MUXOUTN test circuits SDO 1.69k C Hi Hi-Z OH ...
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DiagraMs Timing Diagram Using Internal SCK (SCK HIGH with CS↓ Hi-Z SDO t 3 SCK SDI SLEEP Timing Diagram Using External SCK (SCK LOW with CS↓ Hi-Z SDO t 5 SCK SDI SLEEP ...
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LTC2494 applications inForMation CONVERTER OPERATION Converter Operation Cycle The LTC2494 is a multichannel, low power, delta-sigma, analog-to-digital converter with an easy to use, 4-wire interface and automatic differential input current cancella- tion. Its operation is made up of four states ...
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This enables external RC networks and high impedance sen- sors to directly interface to the LTC2494 without external amplifiers. The remaining common mode input current is eliminated by either balancing the differential ...
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LTC2494 applications inForMation In order to achieve optimum performance external amplifier is not used, short these pins directly together (ADCINP to MUXOUTP and ADCINN to MUXOUTN) and minimize their capacitance to ground. SERIAL INTERFACE PINS The LTC2494 transmits ...
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Bit 20 (fourth output bit) is the most significant bit (MSB) of the result. This bit in conjunction with Bit 21 also pro- vides underrange and overrange indication. If both Bit 21 and Bit 20 are HIGH, the ...
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LTC2494 applications inForMation Table 2. LTC2494 Output Data Format DIFFERENTIAL INPUT VOLTAGE BIT EOC ≥ FS FS** – 1LSB 0 0.5 • FS** 0 0.5 • FS** – 1LSB ...
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Table 3. Channel Selection MUX ADDRESS ODD/ SGL SIGN ...
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LTC2494 applications inForMation Table 4. Converter Configuration SGL ODD EN2 ...
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Table 5a. Performance vs Gain in Normal Speed Mode (V GAIN 1 Input Span ±2.5 LSB 38.1 Noise Free Resolution* 65536 Gain Error 5 Offset Error 0.5 Table 5b. Performance vs Gain in 2x Speed Mode (V GAIN ...
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LTC2494 applications inForMation 1020 REF 960 SLOPE = 2.45 LSB /K 16 800 640 480 320 160 0 0 100 200 300 TEMPERATURE (K) Figure 4. Internal PTAT Digital Output vs Temperature Table ...
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CS 1 SCK (EXTERNAL) SDI DON'T CARE 1 Hi-Z SDO EOC BIT 23 BIT 22 CONVERSION SLEEP edge). The channel selection and converter configuration mode will be used for the following conversion cycle. If the input channel or ...
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LTC2494 applications inForMation CS SCK (EXTERNAL) SDI DON'T CARE SDO CONVERSION SLEEP Figure 7. External Serial Clock, Reduced Output Data Length and Valid Channel Selection SCK (EXTERNAL) SDI DON'T CARE 1 0 SDO EOC “0” BIT 23 ...
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External Serial Clock, 3-Wire I/O This timing mode uses a 3-wire serial I/O interface. The conversion result is shifted out of the device by an exter- nally generated serial clock (SCK) signal (see Figure 8 permanently ...
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LTC2494 applications inForMation The serial data output pin (SDO) is Hi-Z as long HIGH. At any time during the conversion cycle, CS may be pulled LOW in order to monitor the state of the converter. Once CS ...
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SCK (INTERNAL) SDI DON'T CARE 1 0 EOC “0” SDO BIT 23 BIT 22 CONVERSION remains unchanged. In order to program both the input channel and converter configuration, CS must go HIGH after the ...
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LTC2494 applications inForMation Whenever SCK is LOW, the LTC2494’s internal pull-up at SCK is disabled. Normally, SCK is not externally driven if the device is operating in the internal SCK timing mode. However, certain applications may require an external driver ...
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INPUT EXTERNAL MULTIPLEXER + CONNECTION I IN 100 IN + MUXOUTP – 100 – IN MUXOUTN EXTERNAL + I CONNECTION REF + REF – I REF – REF SWITCHING FREQUENCY f = 123kHz INTERNAL OSCILLATOR SW ...
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LTC2494 applications inForMation difference between V and V IN(CM) REF(CM) common mode voltage of 2.5V and an input common mode of 1.5V, the common mode input current is approximately 0.74µA (in simultaneous 50Hz/60Hz rejection mode). This common mode input current ...
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REF + V = 3.75V IN 70 – 1.25V GND 25° 0.01µF REF ...
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LTC2494 applications inForMation In addition to the reference sampling charge, the reference ESD projection diodes have a temperature dependent leak- age current. This leakage current, nominally 1nA (±10nA max) results in a small gain error. A 100Ω reference resistance will ...
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The user can expect to achieve this level of performance using the internal oscillator, as shown in Figures 23, 24 and 25. Measured values of normal mode rejection are shown superimposed over the theoretical values in all three ...
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LTC2494 applications inForMation 0 V IN(P-P) V IN(P-P) –20 (150% OF FULL SCALE) –40 –60 –80 –100 –120 105 120 135 150 165 180 195 210 225 240 INPUT FREQUENCY (Hz) Figure 26. ...
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IN(CM) REF(CM REF EXT CLOCK 85° 25°C A – ...
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LTC2494 package Description 5.50 0.05 4.10 0.05 3.00 REF 5.00 0.10 PIN 1 TOP MARK (SEE NOTE 6) 7.00 0.10 NOTE: 1. DRAWING CONFORMS TO JEDEC PACKAGE OUTLINE M0-220 VARIATION WHKD 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE ...
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... Revised Typical Application drawing Added Note 18 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 representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. LTC2494 ...
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... Pin Compatible with LTC2494/LTC2449/LTC2498 Pin Compatible with LTC2494/LTC2496/LTC2449 www.linear.com ● SDI ΔΣ ADC SCK WITH EASY DRIVE SDO INPUTS CS 0.1µF 0.1µF 2494 TA02 Noise, 2ppm INL Noise RMS LT 0710 REV D • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 2007 2494fd ...