AD7908 Analog Devices, AD7908 Datasheet
AD7908
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AD7908 Summary of contents
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... AD7908/AD7918/AD7928 PRODUCT HIGHLIGHTS 1. High Throughput with Low Power Consumption. The AD7908/ AD7918/AD7928 offer MSPS throughput rates. At the maximum throughput rate with 3 V supplies, the AD7908/ AD7918/AD7928 dissipate just power maximum. 2. Eight Single-Ended Inputs with a Channel Sequencer. A sequence of channels can be selected, through which the ADC cycles and converts on ...
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... AD7908/AD7918/AD7928 TABLE OF CONTENTS Features .............................................................................................. 1 General Description ......................................................................... 1 Functional Block Diagram .............................................................. 1 Product Highlights ........................................................................... 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 AD7908 Specifications................................................................. 3 AD7918 Specifications................................................................. 5 AD7928 Specifications................................................................. 7 Timing Specifications .................................................................. 9 Absolute Maximum Ratings.......................................................... 10 ESD Caution................................................................................ 10 Pin Configuration and Function Descriptions........................... 11 Terminology .................................................................................... 12 Typical Performance Characteristics ........................................... 13 Performance Curves................................................................... 13 REVISION HISTORY 12/10—Rev Rev. D Changes to Features Section ...
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... SPECIFICATIONS AD7908 SPECIFICATIONS 2 5.25 V, REF = 2 DRIVE IN Table 1. Parameter DYNAMIC PERFORMANCE Signal-to-(Noise + Distortion) (SINAD) 2 Signal-to-Noise Ratio (SNR) 2 Total Harmonic Distortion (THD) Peak Harmonic or Spurious Noise (SFDR) 2 Intermodulation Distortion (IMD) Second-Order Terms Third-Order Terms Aperture Delay Aperture Jitter 2 Channel-to-Channel Isolation ...
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... AD7908/AD7918/AD7928 Parameter LOGIC OUTPUTS Output High Voltage Output Low Voltage Floating-State Leakage Current Floating-State Output Capacitance 3 Output Coding CONVERSION RATE Conversion Time Track-and-Hold Acquisition Time Throughput Rate POWER REQUIREMENTS DRIVE Normal Mode (Static) Normal Mode (Operational) Using Auto Shutdown Mode ...
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... V V min DRIVE 0.3 × max DRIVE ±1 μA max 10 pF max Rev Page AD7908/AD7918/AD7928 , unless otherwise noted. Test Conditions/Comments kHz sine wave MHz IN SCLK B models W models B models W models fa = 40.1 kHz 41.5 kHz f = 400 kHz ...
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... AD7908/AD7918/AD7928 Parameter LOGIC OUTPUTS Output High Voltage Output Low Voltage Floating-State Leakage Current Floating-State Output Capacitance 3 Output Coding CONVERSION RATE Conversion Time Track-and-Hold Acquisition Time Throughput Rate POWER REQUIREMENTS DRIVE Normal Mode (Static) Normal Mode (Operational) Using Auto Shutdown Mode ...
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... V V min DRIVE 0.3 × max DRIVE ±1 μA max 10 pF max Rev Page AD7908/AD7918/AD7928 , unless otherwise noted. Test Conditions/Comments kHz sine wave MHz IN SCLK @ models @ models @ 3 V typically models W models @ 5 V typically − ...
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... AD7908/AD7918/AD7928 Parameter LOGIC OUTPUTS Output High Voltage Output Low Voltage Floating-State Leakage Current Floating-State Output Capacitance 3 Output Coding CONVERSION RATE Conversion Time Track-and-Hold Acquisition Time Throughput Rate POWER REQUIREMENTS DRIVE Normal Mode (Static) Normal Mode (Operational) Using Auto Shutdown Mode ...
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... Power-up time from full power-down/auto shutdown mode I 200µ OUTPUT PIN C L 50pF I 200µA OH Figure 2. Load Circuit for Digital Output Timing Specifications Rev Page AD7908/AD7918/AD7928 1 ) and timed from a voltage level of 1.6 V. See Figure DRIVE , quoted in the timing characteristics is the true bus relinquish 8 1.6V ...
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... AD7908/AD7918/AD7928 ABSOLUTE MAXIMUM RATINGS T = 25°C, unless otherwise noted. A Table 5. Parameter Rating AV to AGND −0 AGND −0 DRIVE Analog Input Voltage to AGND −0 Digital Input Voltage to AGND −0 Digital Output Voltage to AGND −0 ...
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... Serial Clock. Logic input. SCLK provides the serial clock for accessing data from the part. This clock input is also used as the clock source for the conversion process of the AD7908/AD7918/AD7928. 2 DIN Data In. Logic input. Data to be written to the control register of the AD7908/AD7918/AD7928 is provided on this input and is clocked into the register on the falling edge of SCLK (see the Control Register section Chip Select ...
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... The figure is given worst case across all eight channels for the AD7908/AD7918/ AD7928. Power Supply Rejection (PSR) Variations in power supply affect the full-scale transition, but not the converter’ ...
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... 5.25V DD DRIVE 4.75V DD DRIVE 3.60V DD DRIVE 2.70V DD DRIVE 1000 Rev Page AD7908/AD7918/AD7928 –10 200mV p-p SINEWAVE REF = 2.5V, 1µF CAPACITOR 25°C –20 A –30 –40 –50 –60 –70 –80 –90 0 100 200 ...
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... AD7908/AD7918/AD7928 – 1MSPS R = 1000Ω SAMPLE 25°C A –55 RANGE = 0V TO REF 5.25V DD –60 – – 50Ω IN – 10Ω IN –80 –85 –90 10 100 INPUT FREQUENCY (kHz) Figure 8. AD7928 THD vs. Analog Input Frequency for Various Source Impedances 1 ...
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... The control register on the AD7908/AD7918/AD7928 is a 12-bit, write-only register. Data is loaded from the DIN pin of the AD7908/AD7918/AD7928 on the falling edge of SCLK. The data is transferred on the DIN line at the same time that the conversion result is read from the part. The data transferred on the DIN line corresponds to the AD7908/AD7918/AD7928 configuration for the next conversion ...
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... PM0 Mode 1 1 Normal Operation. In this mode, the AD7908/AD7918/AD7928 remain in full power mode regardless of the status of any of the logic inputs. This mode allows the fastest possible throughput rate from the AD7908/AD7918/AD7928 Full Shutdown. In this mode, the AD7908/ AD7918/AD7928 is in full shutdown mode with all circuitry powering down. The AD7908/AD7918/AD7928 retains the information in the control register while in full shutdown ...
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... LSBs of the SHADOW register. To select a sequence of channels, the associated channel bit must be set for each analog input. The AD7908/AD7918/ AD7928 continuously cycle through the selected channels in ascending order beginning with the lowest channel, until a ...
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... The AD7908/AD7918/AD7928 are high speed, 8-channel, 8-bit, 10-bit, and 12-bit, single-supply ADCs, respectively. The parts can be operated from a 2 5.25 V supply. When operated from either supply, the AD7908/AD7918/AD7928 are capable of throughput rates of 1 MSPS when provided with a 20 MHz clock. ...
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... AD7928 (10 bits of data for the /256 AD7908 AD7918 and 8 bits of data for the AD7908, each followed by /1024 AD7918 /4096 AD7928 two and four trailing zeros, respectively). For applications ...
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... AD7908/AD7918/AD7928 is written to and the SEQ and SHADOW bits are configured with any bit combination µC/µP except completion of the sequence, the AD7908/ AD7918/AD7928 sequencer returns to the first selected channel in the SHADOW register and commence the sequence again. ...
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... Absolute Maximum Ratings section. Reference An external reference source should be used to supply the 2.5 V reference to the AD7908/AD7918/AD7928. Errors in the reference source results in gain errors in the AD7908/ AD7918/AD7928 transfer function and adds to the specified full-scale errors of the part. A capacitor of at least 0.1 μF should be placed on the REF pin ...
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... AD7908/AD7918/AD7928 the operation of the AD7908/AD7918/AD7928 in this mode. In shutdown mode, all internal circuitry on the AD7908/AD7918/ AD7928 is powered down. The part retains information in the control register during shutdown. The AD7908/AD7918/ AD7928 remains in shutdown until the next CS falling edge it receives. On this CS falling edge, the track-and-hold that was in hold while the part was in shutdown returns to track. Wakeup time from auto shutdown is 1 μ ...
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... DOUT line goes back into three-state, and the control register is not updated; otherwise DOUT returns to three-state on the 16th SCLK falling edge as shown in Figure 28 conversion process and to access data from the AD7908/ AD7918/AD7928. For the AD7908/AD7918/AD7928, the Rev Page AD7908/AD7918/AD7928 CORRECT VALUE IN CONTROL ...
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... CS and the track-and-hold begins to track the first channel selected in the sequence. The AD7908 outputs a leading zero and three channel address bits that the conversion result corresponds to, followed by the 8-bit conversion result and four trailing zeros. The AD7918 ...
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... SCLK ADD2 ADD1 ADD0 DOUT THREE-STATE THREE IDENTIFICATION BITS ZERO t 9 WRITE SEQ1 DONTC ADD2 DIN Figure 26. AD7908 Serial Interface Timing Diagram SCLK ADD2 ADD1 ADD0 DOUT THREE-STATE THREE IDENTIFICATION BITS ZERO t 9 WRITE ...
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... N, then equidistant sampling is implemented by the DSP. AD7908/AD7918/AD7928 to DSP563xx The connection diagram in Figure 32 shows how the AD7908/AD7918/AD7928 can be connected to the synchronous serial interface (ESSI) of the DSP563xx family of DSPs from Motorola. Each ESSI (two on board) is operated in synchronous mode (SYN bit in CRB = 1) with internally generated word length frame sync for both Tx and Rx (Bit FSL1 = 0 and Bit FSL0 = 0 in CRB) ...
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... AGND to DGND connection, the connection should be made at only one point in the plane. Using a star ground point, the connection should be established as close as possible to the AD7908/ AD7918/AD7928. Avoid running digital lines under the device, as these couple noise onto the die. The analog ground plane should be allowed to run under the AD7908/AD7918/AD7928 to avoid noise coupling ...
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... AD7908/AD7918/AD7928 OUTLINE DIMENSIONS COPLANARITY 6.60 6.50 6. 4.50 4.40 4.30 6.40 BSC 1 10 PIN 1 0.65 BSC 1.20 MAX 0.15 0.20 0.05 0.09 0.30 0.19 SEATING 0.10 PLANE COMPLIANT TO JEDEC STANDARDS MO-153-AC Figure 33. 20-Lead Thin Shrink Small Outline Package [TSSOP] (RU-20) Dimensions shown in millimeters Rev Page 0.75 8° 0.60 0° 0.45 ...
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... The EVAL-AD79x8CBZ can be used as a standalone evaluation board or in conjunction with the evaluation controller board for evaluation/demonstration purposes. The board comes with one chip of each the AD7908, AD7918, and AD7928. 4 The EVAL-CONTROL BRD is a complete unit allowing control and communicate with all Analog Devices evaluation boards ending in the CB designators. To order a complete evaluation kit, order the particular ADC evaluation board, such as the EVAL-AD79x8CB, the EVAL-CONTROL BRD2, and transformer ...
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... AD7908/AD7918/AD7928 NOTES Rev Page ...
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... NOTES AD7908/AD7918/AD7928 Rev Page ...
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... AD7908/AD7918/AD7928 NOTES ©2006–2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D03089-0-12/10(D) Rev Page ...