EVAL-AD7951CBZ Analog Devices Inc, EVAL-AD7951CBZ Datasheet
EVAL-AD7951CBZ
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EVAL-AD7951CBZ Summary of contents
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FEATURES Multiple pins/software programmable input ranges ±5 V, ±10 V Pins or serial SPI® compatible input ranges/mode selection Throughput 1 MSPS (warp mode) 800 kSPS (normal mode) 670 kSPS (impulse mode) 14-bit resolution with no missing ...
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... Driver Amplifier Choice ........................................................... 21 Voltage Reference Input/Output .............................................. 21 Power Supplies............................................................................ 22 Conversion Control ................................................................... 23 Interfaces.......................................................................................... 24 Digital Interface.......................................................................... 24 Parallel Interface......................................................................... 24 Serial Interface ............................................................................ 25 Master Serial Interface............................................................... 25 Slave Serial Interface .................................................................. 27 Hardware Configuration ........................................................... 29 Software Configuration ............................................................. 29 Microprocessor Interfacing....................................................... 30 Application Information................................................................ 31 Layout Guidelines....................................................................... 31 Evaluating Performance ............................................................ 31 Outline Dimensions ....................................................................... 32 Ordering Guide .......................................................................... 32 Rev Page ...
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SPECIFICATIONS AVDD = DVDD = 5 V; OVDD = 2 5.5 V; VCC = 15 V; VEE = − Table 2. Parameter RESOLUTION ANALOG INPUT Voltage Range Analog Input CMRR Input Current Input Impedance ...
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AD7951 Parameter REFERENCE BUFFER REFBUFIN Input Voltage Range EXTERNAL REFERENCE Voltage Range Current Drain TEMPERATURE PIN Voltage Output Temperature Sensitivity Output Resistance DIGITAL INPUTS Logic Levels DIGITAL OUTPUTS Data Format 5 Pipeline ...
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TIMING SPECIFICATIONS AVDD = DVDD = 5 V; OVDD = 2 5.5 V; VCC = 15 V; VEE = − Table 3. Parameter CONVERSION AND RESET (See Figure 33 and Figure 34) Convert Pulse Width Time ...
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AD7951 Parameter SLAVE SERIAL/SERIAL CONFIGURATION INTERFACE MODES (See Figure 42, Figure 43, and Figure 45) External SDCLK, SCCLK Setup Time External SDCLK Active Edge to SDOUT Delay SDIN/SCIN Setup Time SDIN/SCIN Hold Time External SDCLK/SCCLK Period External SDCLK/SCCLK High External ...
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ABSOLUTE MAXIMUM RATINGS Table 5. Parameter Rating Analog Inputs/Outputs 1 1 IN+ , IN− to AGND VEE − 0 VCC + 0.3 V REF, REFBUFIN, TEMP, AVDD + 0 AGND − 0.3 V REFGND to AGND ...
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AD7951 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS BYTESWAP D0/DIVSCLK[0] D1/DIVSCLK[ CONNECT Table 6. Pin Function Descriptions Pin No. Mnemonic Type 1 Description AGND P Analog Power Ground Pins. Ground reference point for all analog I/O. ...
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Pin No. Mnemonic Type Description DI/O In parallel mode, this output is used as Bit 2 of the parallel port data output bus. EXT/INT Serial Data Clock Source Select. In serial mode, this input is used ...
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AD7951 1 Pin No. Mnemonic Type Description parallel mode, this output is used as Bit 9 of the parallel port data output bus. RDERROR Serial Data Read Error. In serial slave mode (SER/PAR = high, ...
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Pin No. Mnemonic Type Description 45 TEMP AO Temperature Sensor Analog Output. Enabled when the internal reference is turned on (PDREF = PDBUF = low). See the Temperature Sensor section. 46 REFBUFIN AI Reference Buffer Input. When using an ...
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AD7951 TYPICAL PERFORMANCE CHARACTERISTICS AVDD = DVDD = 5 V; OVDD = 5 V; VCC = 15 V; VEE = − 1.0 0.5 0 –0.5 –1.0 0 4096 8192 CODE Figure 5. Integral Nonlinearity vs. Code 250 200 ...
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SNR = 85.4dB THD = –107dB SFDR = 116dB –40 SINAD = 85.4dB –60 –80 –100 –120 –140 –160 0 100 200 300 FREQUENCY (kHz) Figure 11. FFT 20 kHz ENOB 82 80 ...
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AD7951 – 10V ±5V ±10V –100 –104 –108 –112 –116 –120 –55 –35 – TEMPERATURE (°C) Figure 17. THD vs. Temperature 1.5 ZERO ERROR POSITIVE FS ERROR 1.0 NEGATIVE FS ERROR 0.5 ...
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PD = PDBUF = PDREF = HIGH VEE = –15V 600 VCC = +15V DVDD OVDD AVDD 500 400 300 200 100 0 –55 –35 – TEMPERATURE (°C) Figure 23. Power-Down Operating Currents vs. Temperature ...
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AD7951 TERMINOLOGY Least Significant Bit (LSB) The least significant bit, or LSB, is the smallest increment that can be represented by a converter. For an analog-to-digital converter with N bits of resolution, the LSB expressed in volts is V (max) ...
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THEORY OF OPERATION IN+ REF REFGND 8,192C IN– OVERVIEW The AD7951 is a very fast, low power, precise, 14-bit analog-to- digital converter (ADC) using successive approximation capacitive digital-to-analog (CDAC) converter architecture. The AD7951 can be configured at any time for ...
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AD7951 MODES OF OPERATION The AD7951 features three modes of operation: warp, normal, and impulse. Each of these modes is more suitable to specific applications. The mode is configured with the input pins, WARP and IMPULSE, or via the configuration ...
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TYPICAL CONNECTION DIAGRAM Figure 27 shows a typical connection diagram for the AD7951 using the internal reference, serial data and serial configuration interfaces. Different circuitry from that shown in Figure 27 is optional and is discussed in the following sections. ...
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AD7951 ANALOG INPUTS Input Range Selection In parallel mode and serial hardware mode, the input range is selected by using the BIPOLAR (bipolar) and TEN (10 Volt range) inputs. See Table 6 for pin details and the Hardware Configuration section ...
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DRIVER AMPLIFIER CHOICE Although the AD7951 is easy to drive, the driver amplifier must meet the following requirements: • For multichannel, multiplexed applications, the driver amplifier and the AD7951 analog input circuit must be able to settle for a full-scale ...
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AD7951 Internal Reference (REF = 5 V) (PDREF = Low, PDBUF = Low) To use the internal reference, the PDREF and PDBUF inputs must be low. This enables the on-chip band gap reference, buffer, and TEMP sensor resulting in a ...
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Power Sequencing The AD7951 is independent of power supply sequencing and is very insensitive to power supply variations on AVDD over a wide frequency range as shown in Figure 31. 80 EXT REF 75 INT REF ...
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AD7951 INTERFACES DIGITAL INTERFACE The AD7951 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 AD7951 ...
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Interface (Master or Slave) The BYTESWAP pin allows a glueless interface to an 8-bit bus. As shown in Figure 38, when BYTESWAP is low, the LSB byte is output on D[7:0] and the MSB is output on D[13:8]. When ...
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AD7951 CS CNVST BUSY t 29 SYNC t 14 SDCLK t 15 SDOUT t 16 CS, RD CNVST BUSY t 17 SYNC SDCLK t 18 SDOUT Figure 40. ...
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SLAVE SERIAL INTERFACE The pins multiplexed on D[19:2] used for slave serial interface are: EXT/ INT , INVSCLK, SDIN, SDOUT, SDCLK and RDERROR. External Clock (SER/ PAR = High, EXT/ INT = High) Setting the EXT/ INT = high allows ...
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AD7951 External Clock Data Read After/During Conversion It is also possible to begin to read data after conversion and continue to read the last bits after a new conversion has been initiated. This method allows the full throughput and the ...
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HARDWARE CONFIGURATION The AD7951 can be configured at any time with the dedicated hardware pins WARP, IMPULSE, BIPOLAR, TEN, OB and PD for parallel mode (SER/ PAR = low) or serial hardware mode (SER/ PAR = high, HW/ ...
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AD7951 WARP = BIP = IMPULSE = TEN = CNVST BUSY t 31 SCCS t 31 SCCLK 1 2 SCIN X BIPOLAR START MICROPROCESSOR ...
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... ADC and connect it with short, thick traces. EVALUATING PERFORMANCE A recommended layout for the AD7951 is outlined in the EVAL-AD7951CB evaluation board documentation. The evaluation board package includes a fully assembled and tested evaluation board, documentation, and software for controlling the board from a PC via the EVAL-CONTROL BRD3. Rev Page AD7951 ...
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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 evaluation boards ending with the CB designators. ©2006 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners ...