LTC1418 LINER [Linear Technology], LTC1418 Datasheet
LTC1418
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LTC1418 Summary of contents
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... The low 15mW power dissipation is made even more attractive with two user selectable power shutdown modes. The LTC1418 converts 0V to 4.096V unipolar inputs from a single 5V supply and 2.048V bipolar inputs from 5V supplies. DC specs include 1.25LSB INL, 1LSB DNL and no missing codes over temperature ...
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... Bipolar Operation.........................(V Digital Output Voltage Unipolar Operation .................. – 0. Bipolar Operation........... (V – 0.3V Power Dissipation.............................................. 500mW Operation Temperature Range LTC1418C................................................ LTC1418I............................................ – Storage Temperature Range ................. – 150 C Lead Temperature (Soldering, 10 sec).................. 300 VERTER C HARA TERISTICS C ...
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... Unipolar, RD High (Note 5) Bipolar, RD High (Note 5) Nap Mode SHDN = 0V (Note 12) Sleep Mode SHDN = 0V (Note 12) Bipolar, RD High (Note 5) Nap Mode SHDN = 0V (Note 12) Sleep Mode SHDN = 0V (Note 12) Unipolar Bipolar LTC1418 MIN TYP MAX UNITS 79 81.5 dB – 94 – – ...
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... LTC1418 CHARACTERISTICS SYMBOL PARAMETER f Maximum Sampling Frequency SAMPLE(MAX) t Conversion Time CONV t Acquisition Time ACQ Acquisition Plus Conversion Time ACQ CONV Setup Time CONVST Setup Time SHDN Setup Time to Ensure Nap Mode 3 t SHDN to CONVST Wake-Up Time from Nap Mode ...
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... SAMPLE f = 97.509765kHz IN –20 SFDR = 94.29 SINAD = 81.4 –40 –60 –80 –100 –120 100 FREQUENCY (kHz) 1418 F02b LTC1418 S/( Input Frequency and Amplitude 0dB –20dB –60dB 10k 100k 1M INPUT FREQUENCY (Hz) ...
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... LTC1418 W U TYPICAL PERFORMANCE CHARACTERISTICS Power Supply Feedthrough vs Ripple Frequency 0 –20 –40 – –80 DD DGND –100 –120 1k 10k 100k 1M 10M FREQUENCY (Hz) 1418 G08 V Supply Current vs DD Temperature (Unipolar Mode 100 125 –75 –50 – 150 ...
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... Analog ground for unipolar operation. V (Pin 28): 5V Positive Supply. Bypass to AGND with tantalum in parallel with 0.1 F ceramic. Load Circuits for Output Float Delay 5V 1k DBN DGND A) V AND 1418 TC01 LTC1418 5V 1k DBN 30pF 30pF TO HI HI-Z OL 1418 TC02 7 ...
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... U U APPLICATIONS INFORMATION CONVERSION DETAILS The LTC1418 uses a successive approximation algorithm and an internal sample-and-hold circuit to convert an analog signal to a 14-bit parallel or serial output. The ADC is complete with a precision reference and an internal clock. The control logic provides easy interface to micro- processors and DSPs (please refer to Digital Interface section for the data format) ...
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... ADC and is directly related to the S/( the equation [S/( – 1.76]/6.02 where N is the effective number of bits of resolution and S/( expressed in dB. At the maximum sampling rate of 200kHz the LTC1418 maintains near ideal ENOBs up to the Nyquist input frequency of 100kHz (refer to Figure 3). LTC1418 0 ...
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... INPUT FREQUENCY (Hz) Figure 4. Distortion vs Input Frequency shown in Figure 4. The LTC1418 has good distortion performance up to the Nyquist frequency and beyond. Intermodulation Distortion If the ADC input signal consists of more than one spectral component, the ADC transfer function nonlinearity can produce intermodulation distortion (IMD) in addition to THD ...
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... If slower op amps are used, more settling time can be provided by increasing the time between conversions. The best choice for an op amp to drive the LTC1418 will depend on the application. Generally, applications fall into two categories: AC applications where dynamic specifica- tions are most critical and time domain applications where DC accuracy and settling time are most critical ...
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... U Input Range The 2.048V and 0V to 4.096V input ranges of the LTC1418 are optimized for low noise and low distortion. Most op amps also perform well over these ranges, allowing direct coupling to the analog inputs and eliminat- ing the need for special translation circuitry. ...
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... INFORMATION UNIPOLAR / BIPOLAR OPERATION AND ADJUSTMENT Figure 9a shows the ideal input/output characteristics for the LTC1418. The code transitions occur midway between successive integer LSB values (i.e., 0.5LSB, 1.5LSB, 2.5LSB, … FS – 1.5LSB). The output code is natural binary with 1LSB = FS/16384 = 4.096V/16384 = 250 V. Figure 9b shows the input/output transfer characteristics for the bipolar mode in two’ ...
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... BOARD LAYOUT AND GROUNDING Wire wrap boards are not recommended for high resolu- tion or high speed A/D converters. To obtain the best performance from the LTC1418, a printed circuit board with ground plane is required. The ground plane under the ADC area should be as free of breaks and holes as possible, such that a low impedance path between all ADC grounds and all ADC decoupling capacitors is provided ...
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... U U APPLICATIONS INFORMATION W U LTC1418 15 ...
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... LTC1418 U U APPLICATIONS INFORMATION Figure 12b. Suggested Evaluation Circuit Board— Component Side Top Silkscreen Figure 12c. Suggested Evaluation Circuit Board—Top Layer 1418 F12b 1418 F12c ...
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... DIGITAL INTERFACE The LTC1418 can operate in serial or parallel mode. In parallel mode the ADC is designed to interface with micro- processors as a memory mapped device. The CS and RD control inputs are common to all peripheral memory interfacing ...
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... LTC1418 U U APPLICATIONS INFORMATION mode is much slower since the reference circuit must power up and settle to 0.005% for full 14-bit accuracy. Sleep mode wake-up time is dependent on the value of the capacitor connected to the REFCOMP (Pin 4). The wake-up time is 30ms with the recommended 10 F capacitor. Shutdown is controlled by Pin 22 (SHDN); the ADC is in shutdown when it is low. The shutdown mode is selected with Pin 25 (CS) ...
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... DATA N DB13 TO DB0 ) t CONV DATA N DB13 TO DB0 ) t (SAMPLE CONV DATA N DB13 TO DB0 LTC1418 DATA ( DB13 TO DB0 1418 F15 t 6 DATA ( DB13 TO DB0 1418 F16 11 1418 F17 19 ...
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... To enable the serial data output buffer and shift clock, CS and RD must be low. Figure 20 shows a function block diagram of the LTC1418 in serial mode. There are two pieces to this circuitry: the conversion clock selection circuit (EXT/INT, EXTCLKIN ...
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... CS selects nap mode. For normal serial port operation, CS can be grounded. D outputs the serial data; 14 bits, MSB first, on the OUT falling edge of each SCLK (see Figures 21 and 22 SCLKs are provided, the 14 data bits will be followed by LTC1418 • • • 17 SCLK ...
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... The data may be captured on either edge. The largest hold time margin is achieved if data is captured on the rising edge of SCLK. BUSY gives the end of conversion indication. When the LTC1418 is configured as a master serial device, BUSY can be used as a framing pulse and to three-state the CONVST (SAMPLE N) ...
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... RD pin. Figures show several serial modes of operation, demonstrating the flexibility of the LTC1418 serial port. Serial Data Output During a Conversion Using Internal Conversion Clock for Conversion and Data Transfer. Figure 22 shows data from the previous ...
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... The internal clock is used as the conversion clock and an external clock is used for the SCLK. This mode is useful in applications where the processor acts as a master serial device. This mode is SPI and MICROWIRE compatible CONVST BUSY SCLK LTC1418 19 D OUT 20 EXT/INT ...
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... D OUT 20 EXT/INT Hi-Z D13 CONV LTC1418 CLKOUT INT DSP SCK MISO 1418 F25a t 8 SAMPLE FILL ...
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... LTC1418 U U APPLICATIONS INFORMATION allows the user to synchronize the A/D conversion to an external clock either to have precise control of the internal bit test timing or to provide a precise conversion time Figure 24, this mode works when the SCLK frequency is very low (less than 30kHz). However, the external conver- sion clock must be between 30kHz and 4 ...
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... MIN 0.125 0.005 (3.175) (0.127) MIN MIN 0.100 0.010 (2.540 0.254) LTC1418 1.370* (34.789) MAX ...
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... Single 5V, 16-Bit, 100ksps ADC DACs LTC1595 16-Bit CMOS Multiplying DAC in SO-8 LTC1596 16-Bit CMOS Multiplying DAC Reference LT1019-2.5 Precision Bandgap Reference Linear Technology Corporation 28 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 www.linear-tech.com LTC1418 – ...