LTC1275 LINER [Linear Technology], LTC1275 Datasheet
LTC1275
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LTC1275 Summary of contents
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... They are built with LTBiCMOS pacitor technology. These devices have 25ppm/ C (max) internal references. The LTC1273 converts unipolar inputs from a single 5V supply. The LTC1275/LTC1276 convert 2.5V and 5V respectively from 5V supplies. Maximum DC specifications include 1/2LSB INL, 3/4LSB DNL and 25ppm/ C full scale drift over temperature. Outstanding AC performance includes 70dB S/( and 77dB THD at the Nyquist input frequency of 150kHz ...
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... S (Notes 1 and 2) Digital Output Voltage (Note 3) LTC1273 .................................... – 0. LTC1275/LTC1276 .............. V Power Dissipation ............................................. 500mW Operating Temperature Range LTC1273AC, LTC1273BC, LTC1275AC LTC1275BC, LTC1276AC, LTC1276BC .... 0.3V DD – 0. 0.3V Storage Temperature Range ................ – 150 C DD Lead Temperature (Soldering, 10 sec)................. 300 C – 0.3V to 12V ...
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... Input Signal 50kHz/150kHz Input Signal f = 29.37kHz 32.446kHz IN1 IN2 CONDITIONS 4.95V V 5.25V (LTC1273) DD 4.75V V 5.25V, – 5.25V V – 2.45V (LTC1275 4.95V V 5.25V, – 5.25V V – 4.95V (LTC1276 High Between Conversions (Sample Mode) During Conversions (Hold Mode) Commercial Military ...
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... High OUT DD CS High (Note OUT OUT DD (Note 5) CONDITIONS LTC1273/LTC1276 (Notes 10, 11) LTC1275 (Note 10) LTC1275 (Note 10) LTC1276 (Notes 10, 11) LTC1275/LTC1276 See Timing Characteristics Figures (Note 5) CONDITIONS (Note 10) Commercial Military Commercial Military C = 50pF L Commercial Military C = 20pF ...
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... Note11: A must not exceed specified accuracy. Therefore the minimum supply voltage for the LTC1273 is + 4.95V. The minimum supplies for the LTC1275 are +4.75V . and – 2.45V and the minimum supplies for the LTC1276 are 4.95V. DD (Note 5) ROM Mode, Parallel Read Timing Diagram ...
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... LTC1273 LTC1275/LTC1276 CHARACTERISTICS HBEN BUSY t 3 DATA DB7 TO DB0 t 12 HOLD TRACK HBEN BUSY t 3 OLD DATA DATA DB7 TO DB0 t 12 HOLD TRACK 6 (Note 5) Slow Memory Mode, Two Byte Read Timing Diagram ...
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... SAMPLE –10 THD –20 2nd HARMONIC 3rd HARMONIC –30 –40 –50 –60 –70 –80 –90 –100 1k 10k 100k 1M INPUT FREQUENCY (Hz) Power Supply Feedthrough vs Ripple Frequency (LTC1275/76 300kHz SAMPLE 1mV) DD RIPPLE DGND (V = 0.1V) RIPPLE 10mV) SS RIPPLE 10k 100k 1M RIPPLE FREQUENCY (Hz) LTC1273/75/76 • ...
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... INPUT FREQUENCY (Hz CTIO S A (Pin 1): Analog Input (LTC1273), 2.5V IN (LTC1275 (LTC1276). V (Pin 2): +2.42V Reference Output. Bypass to AGND REF (10 F tantalum in parallel with 0.1 F ceramic). AGND (Pin 3): Analog Ground. D11-D4 (Pins 4 to 11): Three-State Data Outputs. DGND (Pin 12): Digital Ground. ...
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... (Pin 23): Negative Supply. – 5V for LTC1275/LTC1276. SS Bypass to AGND with 0.1 F ceramic. NC (Pin 23): No Connection for LTC1273. Table 1. Data Bus Output, CS and RD = LOW Pin 4 Pin 5 MNEMONIC* D11 D10 HBEN = LOW DB11 DB10 HBEN = HIGH DB11 DB10 *D11...D0/8 are the ADC data output pins. ...
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... By applying a low distortion sine wave and analyzing the digital output using an FFT algorithm, the ADC’s spectral content can be examined for frequencies outside the fundamental. Figure 2 shows a typical LTC1275 FFT plot. Signal-to-Noise Ratio The Signal-to-Noise plus Distortion Ratio [S/(N + D)] is the ...
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... V through V are the amplitudes of the 2 N second through Nth harmonics. THD versus input fre quency is shown in Figure 4. The LTC1273/LTC1275/ LTC1276 have good distortion performance up to Nyquist and beyond Intermodulation Distortion If the ADC input signal consists of more than one spectral ...
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... S/( becomes dominated by distortion at frequencies far beyond Nyquist. Driving the Analog Input The analog inputs of the LTC1273/LTC1275/LTC1276 are easy to drive. They draw only one small current spike while charging the sample-and-hold capacitor at the end of conversion. During conversion the analog input draws no current ...
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... LTC1273/LTC1276 since the input spans will exceed the supplies and codes will be lost at full scale. Figure 7 shows a typical reference, the LT1019A-2.5 connected to the LTC1275. This will provide an improved drift (equal to the maximum 5ppm the LT1019A-2.5) and a 2.582V full scale. INPUT RANGE ± ...
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... LTC1275 or LTC1276) to the input in Figure 10c and adjusting R8 until the ADC output code flickers between 0000 0000 0000 and 1111 1111 1111. For full scale adjustment, an input voltage of 2.49817V or 4.99636V (FS – 1 1/2LSBs for LTC1275 or LTC1276) is applied to the ...
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... D11....D0/8 ARE THE ADC DATA OUTPUT PINS DB11....DB0 ARE THE 12-BIT CONVERSION RESULTS Figure 12. Internal Logic for Control Inputs CS, RD and HBEN LTC1273 LTC1275/LTC1276 DIGITAL SYSTEM GROUND CONNECTION TO DIGITAL CIRCUITRY LTC1273/75/76 • F11 BUSY D Q CONVERSION START (RISING ...
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... LTC1273 LTC1275/LTC1276 PPLICATI S I FOR ATIO on all three inputs to initiate a conversion. Once initiated it cannot be restarted until the conversion is complete. Converter status is indicated by the BUSY output, and this is low while conversion is in progress. There are two modes of operation as outlined by the timing diagrams of Figures ...
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... The 4MSBs appear on data outputs D11...D8 during all three read operations. MICROPROCESSOR INTERFACING The LTC1273/LTC1275/LTC1276 allow easy interfac- ing to digital signal processors as well as modern high speed, 8-bit or 16-bit microprocessors. Here are sev- eral examples. ...
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... LTC1273 LTC1275/LTC1276 PPLICATI S I FOR ATIO BUSY DATA HOLD TRACK Figure 15. ROM Mode, Parallel Read Timing Diagram (HBEN = LOW) Table 4. ROM Mode, Parallel Read Data Bus Status Data Outputs D11 D10 First Read (Old Data) DB11 DB10 ...
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... LTC1273/75/76 • F17 (HBEN = HIGH) will read the high data byte. This is accomplished with the single 16-bit LOAD instruction below. For the 8085A For the Z80 Z80 8085A ADDITIONAL PINS OMITTED FOR CLARITY LTC1273 LTC1275/LTC1276 A23 ADDRESS BUS A1 ADDRESS AS EN DECODE LTC1273/75/76 CS ...
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... MUX. The CD4520 counter increments the MUX channel after each sample is taken. Figure 22 shows the acquisi- tion time of LTC1275 vs the source resistance. For a 500 maximum “on” resistance of the CD4051, the acquisition time of the ADC is not greatly affected. For larger source resistances, modest increases in acquisi- tion time must be allowed ...
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... I FOR ATIO Demodulating a Signal by Undersampling with LTC1275 Figure 23 shows a 455kHz amplitude modulated input undersampled by the LTC1275. With a 227.5kHz sample rate, the converter provides a 100dB noise floor and 68dB distortion when digitizing the 455kHz AM input. Figure 24 shows an FFT of the AM signal digitized at 212.5kHz. ...
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... LTC1273 LTC1275/LTC1276 PPLICATI S I FOR ATIO 7V 65 1N457 LM134 45.3 1N457 45.3 74HC74 START CLK Q CLR STOP CLK Q CLR 2N2369 2N2369 65 400k 20k 2N5771 620 250pF POLYSTYRENE 74HC03 5V 1N4148 1k 0.001 F 100k Figure 26. Time Measurement with the LTC1273 ...
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... NOTE 0.093 – 0.104 45 (2.362 – 2.642) 0° – 8° TYP 0.050 (1.270) TYP 0.014 – 0.019 (0.356 – 0.482) LTC1273 LTC1275/LTC1276 1.265 0.065 (1.651) TYP 0.018 ± 0.003 (0.457 ± 0.076) 0.598 – ...
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... LTC1273 LTC1275/LTC1276 NORTHEAST REGION Linear Technology Corporation One Oxford Valley 2300 E. Lincoln Hwy.,Suite 306 Langhorne, PA 19047 Phone: (215) 757-8578 FAX: (215) 757-5631 Linear Technology Corporation 266 Lowell St., Suite B-8 Wilmington, MA 01887 Phone: (508) 658-3881 FAX: (508) 658-2701 FRANCE Linear Technology S.A.R.L. Immeuble "Le Quartz" ...