AD7888 Analog Devices, AD7888 Datasheet
AD7888
Specifications of AD7888
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AD7888 Summary of contents
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... GENERAL DESCRIPTION The AD7888 is a high speed, low power, 12-bit ADC that oper- ates from a single 2 5.25 V power supply. The AD7888 is capable of a 125 kSPS throughput rate. The input track-and- hold acquires a signal in 500 ns and features a single-ended sampling scheme. The AD7888 contains eight single-ended analog inputs, AIN1 through AIN8 ...
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... AD7888–SPECIFICATIONS otherwise noted MHz ( 5.25 V); T SCLK DD Parameter DYNAMIC PERFORMANCE 2, 3 Signal to Noise + Distortion Ratio (SNR Total Harmonic Distortion (THD) 2 Peak Harmonic or Spurious Noise 2 Intermodulation Distortion (IMD) Second Order Terms Third Order Terms 2 Channel-to-Channel Isolation Full Power Bandwidth ...
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... ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the AD7888 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high-energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality ...
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... AD7888 1 TIMING SPECIFICATIONS Limit at T (A, B Versions) Parameter 4. 5. SCLK t 14.5 t CONVERT SCLK t 1.5 t ACQ SCLK 0 SCLK t 0 SCLK NOTES 1 Sample tested at 25°C to ensure compliance. All input signals are specified with (10 Mark/Space ratio for the SCLK input is 40/60 to 60/40 ...
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... MSB first. 16 SCLK Serial Clock. Logic Input. SCLK provides the serial clock for accessing data from the part and writing serial data to the Control Register. This clock input is also used as the clock source for the AD7888’s conversion process. REV. C PIN CONFIGURATIONS ...
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... The theoretical signal to (noise + distortion) ratio for an ideal N-bit converter with a sine wave input is given by: Signal to (Noise + Distortion) = (6. 1.76) dB Thus for a 12-bit converter, this is 74 dB. Total Harmonic Distortion Total harmonic distortion (THD) is the ratio of the rms sum of harmonics to the fundamental. For the AD7888 defined as ...
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... CONTROL REGISTER The Control Register on the AD7888 is an 8-bit, write-only register. Data is loaded from the DIN pin of the AD7888 on the rising edge of SCLK. The data is transferred on the DIN line at the same time as the conversion result is read from the part. This requires 16 serial clocks for every data transfer ...
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... The AD7888 is a fast, low power, 12-bit, single supply, 8-channel A/D converter. The part can be operated from 3.6 V) supply or from 5 V (4. 5.25 V) supply. When operated from either supply supply, the AD7888 is capable of throughput rates of 125 kSPS when provided with a 2 MHz clock. ...
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... On power-up, the default AIN selection is AIN1. When returning to normal operation from power-down, the AIN selected will be the same one that was selected prior to power-down being initi- ated. Table II below shows the multiplexer address correspond- ing to each analog input from AIN1 to AIN8 for the AD7888. ADD2 0 0 ...
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... SCLK edge after the falling edge of CS. The first falling SCLK edge after the CS falling edge will cause the part to power up again. When the AD7888 is in full shutdown, the only way to fully power it up again is to reprogram the power management bits to PM1 = PM0 = 0, i ...
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... AD7888 remaining fully powered all the time. Figure 13 shows the general diagram of the operation of the AD7888 in this mode. The data presented to the AD7888 on the DIN line during the first eight clock cycles of the data transfer are loaded to the Control Register. The part will remain powered up at the end of the conversion as long as PM1 and PM0 were set to zero in the write during that conversion ...
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... Figure 15 shows the general diagram of the operation of the AD7888 in this mode. On the first falling SCLK edge after CS goes low, the AD7888 comes out of standby. The AD7888 wake-up time is very short in this mode possible to wake up the part and carry out a valid conversion in the same read/ write operation ...
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... DIN line when reading data from the part. Sixteen serial clock cycles are required to perform the conver- sion process and to access data from the AD7888. In applica- tions where the first serial clock edge, following CS going low falling edge, this edge clocks out the first leading zero. Thus, the first rising clock edge on the SCLK clock has the first lead- ing zero provided ...
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... AD7888 MICROPROCESSOR INTERFACING The serial interface on the AD7888 allows the part to be directly connected to a range of many different microprocessors. This section explains how to interface the AD7888 with some of the more common microcontroller and DSP serial interface protocols. AD7888 to TMS320C5x The serial interface on the TMS320C5x uses a continuous serial clock and frame synchronization signals to synchronize the data transfer operations with peripheral devices like the AD7888 ...
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... The analog ground plane should be allowed to run under the AD7888 to avoid noise coupling. The power supply lines to the AD7888 should use as large a trace as pos- sible to provide low impedance paths and reduce the effects of glitches on the power supply line. Fast switching signals like ...
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... AD7888 OUTLINE DIMENSIONS 4.00 (0.1575) 3.80 (0.1496) 0.25 (0.0098) 0.10 (0.0039) COPLANARITY 0.10 CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. 4.50 4.40 4.30 PIN 1 0.15 0.05 10.00 (0.3937) 9.80 (0.3858 6.20 (0.2441) 1 5.80 (0.2283) 8 1.27 (0.0500) BSC 1.75 (0.0689) 1.35 (0.0531) SEATING 0.51 (0.0201) PLANE 0 ...
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... This can be used as a standalone evaluation board or in conjunction with the EVAL-CONTROL BOARD for evaluation/demonstration purposes. REVISION HISTORY 6/10—Rev Rev. C Changes to Standby Mode Parameter, AD7888 Specifications Section ............................................................................................... 3 Changes to Operating Temperature Range, Commercial (B Version) Parameter, Absolute Maximum Ratings Section ..... 3 Updated Outline Dimensions ....................................................... 16 Changes to Ordering Guide .......................................................... 17 6/01— ...