National Semiconductor ADC08100 Instruction Manual

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National Semiconductor ADC08100 Instruction Manual Manual pdf 5 page image

1.0 Introduction 3.0 Quick StartThe ADC08100EVAL Design Kit (consisting of theADC08100 Evaluation Board, National's WaveVisionsoftware and this manual) is designed to ease evaluationand design-in of Nationals ADC08100 8-bit Analog-to-Digital Converter, which operate at sample rates up to130 Msps.Refer to Figure 1 for locations of test points and majorcomponents.1. Connect the evaluation board to the Digital InterfaceBoard (order number WAVEVSN BRD 3.0). See theDigital Interface Board Manual for operation of thatboard.The WaveVision software operates under MicrosoftWindows. The signal at the Analog Input is digitized andcan be captured and displayed on the computer monitoras dynamic waveforms. The digitized output is alsoavailable at Euro connector J3.1. Install a 100 MHz (or lower) crystal into socket Y1.While the oscillator may be soldered to the board,using a socket will allow you to easily change clockfrequencies.2. Connect a clean power supply to the terminals ofconnector P1. Adjust power supply to voltages of+4.75V to +5.25V and -5.2V to -5.3V beforeconnecting it to the board. Turn on the power andconfirm that there is 3 Volts at the pins of inductorL1.The software can perform an FFT on the captured dataupon command. This FFT display also shows dynamicperformance in the form of SNR, SINAD, THD andSFDR.Evaluation with this system is simplified by connectingthe board to the WaveVision Digital Interface Board(order number WAVEVSN BRD 3.0), which is connectedto a personal computer through a serial communicationport and running WaveVision software, operating underMicrosoft Windows. Use program WAVEVSN2.EXE3. Use VR1 to set the top reference voltage (VRT) forthe ADC to 1.9V at TP2. Use VR2 to set the bottomreference voltage (VRB) for the ADC to 0.3V at TP4.4. Connect the jumper at J4 to pins 1 and 2 (thosefarthest from oscillator Y1).5. Connect a signal of 1.6VP-P amplitude from a 50-Ohm source to Analog Input BNC J2. The ADCinput signal can be observed at TP7. Because ofisolation resistor R17 and the scope probecapacitance, the input signal at TP7 will not havethe same frequency response as the ADC inputsignal.The signal at the Analog Input to the board is digitizedand is available at pins B16 through B19 and C16through C19 of J3. Pins A16 through A21 of J3 areground pins.Provision is made for adjustment of the ReferenceVoltages, VRT and VRB with potentiometers VR1 andVR2, respectively. These voltages are not regulated andwill vary with the input potential at pin 1 of PowerConnector P1.6. The Digital Interface Board should be set up for40MHz operation with an 80MHz crystal installed.See the Digital Interface Board manual.7. See the Digital Interface Board Manual for datagathering instructions.2.0 Board AssemblyThe ADC08100 Evaluation Board may come pre-assembled or as a bare board that must be assembled.Refer to the Bill of Materials for a description ofcomponents, to Figure 1 for major component placementand to Figure 2 for the Evaluation Board schematic.NOTE: The FFT will not indicate the correct frequenciesbecause this information is derived from the clockfrequency selected on the Digital Interface Board. Toshow the correct frequency information on the FFT,double click on the FFT window to open the FFT DialogBox, then click on "Frequency", then click on "OK".Alternatively, you may double click on the data capturewindow before performing the FFT and change thefrequency at "Sampling Rate of This Data (MHz)" to 100to indicate a 100MHz rate.5 http://www.national.com