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National Semiconductor ADC122S655 User Manual

Summary of ADC122S655

  • Page 1

    National semiconductor january 18, 2008 rev – 1.0/cs rohs compliant evaluation board user's guide adc122s655 dual 12-bit, 200 ksps to 500 ksps, simultaneous sampling a/d converter.

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    Http://www.National.Com 2 table of contents 1.0 introduction ............................................................................................................................3 2.0 board assembly .................................................................................................

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    Http://www.National.Com 3 1.0 introduction the adc122s655eb/rohs design kit (consisting of the adc122s655 evaluation board and this user's guide) is designed to ease evaluation and design-in of the national semiconductor adc122s655 12-bit analog-to-digital converter. This adc has two analog input ch...

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    Http://www.National.Com 4 2.0 board assembly the adc122s655eb evaluation board comes fully assembled and ready for use. The provided shorting jumpers are in their recommended locations and suit the needs of most users. The evaluation board also includes a crystal oscillator (y2). Refer to the bill o...

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    Http://www.National.Com 5 7. Apply the signals to control the spi interface at j6 or via5 to via7. See the evaluation board schematic (figure 10) or the j6 header pin out (figure 5) for more details. 3.2 computer mode refer to figure 1 for locations of test points and major components. 1. Run the wv...

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    Http://www.National.Com 6 4.0 functional description table 1 describes the function of the various jumpers on the adc122s655 evaluation board. The evaluation board schematic is shown in figure 10. Jumper pins 1 & 2 pins 2 & 3 jp8 select v a as v ref select +2.5v reg. As v ref jp11 select +5.0v exter...

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    Http://www.National.Com 7 figure 6: system settings window 4.4 power supply connections in both the computer and manual modes, the analog supply voltage (v a ) can range between +4.5v and +5.5v. Typical supply currents when applying an external supply to tp12, 5p0v_rem are as follows: • for +4.5v - ...

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    Http://www.National.Com 8 to view an fft of the data captured, click on the ‘fft’ tab. This plot may be zoomed in on the data plot. A display of dynamic performance parameters in the form of sinad, snr, thd, sfdr and enob will be displayed at the top right hand corner of the fft plot (figure 9). Typ...

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    Http://www.National.Com 9 6.0 evaluation board specifications board size: 3.1" x 1.95" (7.9 cm x 5 cm) power requirements: min: +4.5v, 10ma max: +5.5v, 13ma clock frequency range: 6.4 mhz to 16 mhz differential analog input: +/- vref 7.0 test points, connectors, and jumpers test points on the adc122...

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    Http://www.National.Com 10 8.0 hardware schematic figure 10: adc122s655 evaluation board schematic va _m tp 17 ag n d 1 ag n d vi a7 do u t 1 va _m c3 0 0 r41 51 va s el ec tio n 5 p 0v _m + c1 8 10uf a- vi n tp 11 vr ef 1 u5 ad c 12 2s 65 5- m so p1 0 vr ef 1 ai n + 2 ai n - 3 bi n - 4 va 7 do ut 8...

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    Http://www.National.Com 11 9.0 evaluation board layers figure 11: adc122s655 evaluation board: all layers with silk screen figure 12: adc122s655 evaluation board: top layer figure 13: adc122s655 evaluation board: bottom layer.

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    Http://www.National.Com 12 10.0 evaluation board bill of materials qty. Reference pcb footprint source source part # rating value 3 c18,c19,c24 sm/ct_3216_12 10uf 4 c20,c23,c27,c29 sm/c_0603 50v 0.1uf 21 jp14,c21,c22,r25,c25, r26,c26,r27,r28,r29, r31,r33,r35,r37,r38, r42,r43,c37,c38,c39, c40 ns 1 c3...

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    Http://www.National.Com 13 by using this product, you are agreeing to be bound by the terms and conditions of national semiconductor's end user license agreement. Do not use this product until you have read and agreed to the terms and conditions of that agreement. If you do not agree with them, cont...

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    Important notice texas instruments incorporated and its subsidiaries (ti) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the...