EVAL-AD7643CBZ Analog Devices Inc, EVAL-AD7643CBZ Datasheet
EVAL-AD7643CBZ
Specifications of EVAL-AD7643CBZ
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EVAL-AD7643CBZ Summary of contents
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FEATURES Throughput: 1.25 MSPS INL: ±1.5 LSB typical, ±3 LSB maximum (±11 ppm of full scale) 18-bit resolution with no missing codes Dynamic range typical SINAD: 93.5 dB typical @ 20 kHz (V = 2.5 V) REF THD: ...
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... Initial Version Multiplexed Inputs ..................................................................... 17 Driver Amplifier Choice ........................................................... 18 Voltage Reference Input ............................................................ 18 Power Supply............................................................................... 20 Conversion Control ................................................................... 20 Interfaces.......................................................................................... 21 Digital Interface.......................................................................... 21 Parallel Interface......................................................................... 21 Serial interface ............................................................................ 22 Master Serial Interface............................................................... 22 Slave Serial Interface .................................................................. 24 Microprocessor Interfacing....................................................... 26 Application Hints ........................................................................... 27 Layout .......................................................................................... 27 Evaluating the AD7643 Performance ...................................... 27 Outline Dimensions ....................................................................... 28 Ordering Guide .......................................................................... 28 Rev Page ...
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SPECIFICATIONS AVDD = DVDD = 2.5 V; OVDD = 2 3 Table 2. Parameter RESOLUTION ANALOG INPUT Voltage Range Operating Input Voltage Analog Input CMRR Input Current 2 Input Impedance THROUGHPUT SPEED Complete Cycle Throughput Rate ...
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AD7643 Parameter Turn-On Settling Time REFBUFIN Output Voltage REFBUFIN Output Resistance EXTERNAL REFERENCE Voltage Range Current Drain REFERENCE BUFFER REFBUFIN Input Voltage Range REFBUFIN Input Current TEMPERATURE PIN Voltage Output Temperature Sensitivity Output Resistance DIGITAL INPUTS Logic Levels V IL ...
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TIMING SPECIFICATIONS AVDD = DVDD = 2.5 V; OVDD = 2 3 Table 3. Parameter CONVERSION AND RESET (Refer to Figure 30 and Figure 31) Convert Pulse Width Time Between Conversions CNVST Low to BUSY High ...
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AD7643 Table 4. Serial Clock Timings in Master Read After Convert Mode DIVSCLK[1] DIVSCLK[0] SYNC to SCLK First Edge Delay Minimum Internal SCLK Period Minimum Internal SCLK Period Maximum Internal SCLK High Minimum Internal SCLK Low Minimum SDOUT Valid Setup ...
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ABSOLUTE MAXIMUM RATINGS Table 5. Parameter Analog Inputs/Outputs 1 IN+ , IN−, REF, REFBUFIN, TEMP, INGND, REFGND to AGND Ground Voltage Differences AGND, DGND, OGND Supply Voltages AVDD, DVDD OVDD AVDD to DVDD AVDD, DVDD to OVDD Digital Inputs 2 ...
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AD7643 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS Table 6. Pin Function Descriptions Pin 1 No. Mnemonic Type Description AGND P Analog Power Ground Pin. 1, 36, 41 AVDD P Input Analog Power Pins. Nominally 2 ...
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Pin 1 No. Mnemonic Type Description 14 D7 DI/O When MODE[1: this output is used as Bit 7 of the parallel port data output bus. or INVSYNC When MODE[1: (serial mode), invert sync ...
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AD7643 Pin 1 No. Mnemonic Type Description Read Data. When CS and RD are both low, the interface parallel or serial output bus is enabled Chip Select. When CS and RD are both low, ...
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TERMINOLOGY Integral Nonlinearity Error (INL) Linearity error refers to the deviation of each individual code from a line drawn from negative full scale through positive full scale. The point used as negative full scale occurs ½ LSB before the first ...
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AD7643 TYPICAL PERFORMANCE CHARACTERISTICS 3.0 2.5 2.0 1.5 1.0 0.5 0 –0.5 –1.0 –1.5 –2.0 –2.5 –3.0 0 65536 131072 CODE Figure 5. Integral Nonlinearity vs. Code 40000 35000 33606 30000 25000 23521 20000 17320 15000 10000 4848 5000 3062 ...
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FREQUENCY (kHz) Figure 11. FFT 20 kHz SINAD 87 ENOB 100 FREQUENCY (kHz) ...
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AD7643 96.0 95.5 95.0 SNR 94.5 SINAD 94.0 93.5 93.0 –60 –50 –40 –30 INPUT LEVEL (dB) Figure 17. SNR and SINAD vs. Input Level (Referred to Full Scale –55 –35 ...
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APPLICATIONS INFORMATION IN+ MSB 131,072C REF REFGND 131,072C 65,536C MSB IN– CIRCUIT INFORMATION The AD7643 is a very fast, low power, single-supply, precise 18-bit ADC using successive approximation architecture. The AD7643 is capable of converting 1,250,000 samples per second (1.25 ...
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AD7643 TRANSFER FUNCTIONS Using the OB/ 2C digital input, except in 18-bit interface mode, the AD7643 offers two output codings: straight binary and twos complement. The LSB size with V = 2.048 × V REF 262,144, which ...
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TYPICAL CONNECTION DIAGRAM Figure 23 shows a typical connection diagram for the AD7643. Different circuitry shown in this diagram is optional and is discussed in the following sections. ANALOG INPUTS Figure 24 shows an equivalent circuit of the input structure ...
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AD7643 DRIVER AMPLIFIER CHOICE Although the AD7643 is easy to drive, the driver amplifier needs to meet the following requirements: • For multichannel, multiplexed applications, the driver amplifier and the AD7643 analog input circuit must be able to settle for ...
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Internal Reference (PDBUF = Low, PDREF = Low) To use the internal reference, the PDREF and PDBUF inputs must both be low. This produces a 1.2 V band gap output on REFBUFIN, which is amplified by the internal buffer and ...
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AD7643 POWER SUPPLY The AD7643 uses three sets of power supply pins: an analog 2.5 V supply AVDD, a digital 2.5 V core supply DVDD, and a digital input/output interface supply OVDD. The OVDD supply allows direct interface with any ...
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INTERFACES DIGITAL INTERFACE The AD7643 has a versatile digital interface that can be set up as either a serial or a parallel interface with the host system. The serial interface is multiplexed on the parallel data bus. The AD7643 digital ...
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AD7643 16-Bit and 8-Bit Interface (Master or Slave) In the 16-bit (MODE[1: and 8-bit (MODE[1: interfaces, the A0/A1 pins allow a glueless interface to a 16- or 8-bit bus, as shown in Figure 35. By connecting ...
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EXT/INT = 0 CS CNVST BUSY t 29 SYNC SCLK t 15 SDOUT D17 Figure 36. Master Serial Data Timing for Reading (Read After Convert) EXT/INT = 0 ...
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AD7643 SLAVE SERIAL INTERFACE External Clock The AD7643 is configured to accept an externally supplied serial data clock on the SCLK pin when the EXT/ INT pin is held high. In this mode, several methods can be used to read ...
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EXT/INT = 1 CS BUSY SCLK D17 D16 SDOUT SDIN X17 X16 t 33 Figure 39. Slave Serial Data Timing for Reading (Read ...
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AD7643 MICROPROCESSOR INTERFACING The AD7643 is ideally suited for traditional dc measurement applications supporting a microprocessor, and ac signal processing applications interfacing to a digital signal processor. The AD7643 is designed to interface with a parallel 8-bit or 16-bit wide ...
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... EVALUATING THE AD7643 PERFORMANCE A recommended layout for the AD7643 is outlined in the documentation of the EVAL-AD7643-CB the AD7643. The evaluation board package includes a fully assembled and tested evaluation board, documentation, and software for controlling the board from a PC via the CONTROL BRD3. ...
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... This board can be used as a standalone evaluation board or in conjunction with the EVAL-CONTROL BRD3 for evaluation/demonstration purposes. 3 This board allows control and communicate with all Analog Devices, Inc. evaluation boards ending in the CB designators. ©2006 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners ...