a Evaluation Board for 12-bit high speed, low power, successive-approximation ADC EVAL-AD7472CB FEATURES OPERATING THE AD7472 EVALUATION BOARD Full-Featured Evaluation Board for the AD7472 EVAL-CONTROL BOARD Compatible HSC-INTERFACE BOARD Compatible Stand Alone Capability On-Board Analog Buffering and Reference Optional On-Board Analog Bias-Up Circuit Optional On-Board Burst Clock Generator Circuit Various Linking Options PC Software for Control and Data Analysis when used with EVAL-CONTROL BOARD Power Supplies When using this evaluation board with the EVAL-CONTROL BOARD all supplies are provided from the EVALCONTROL BOARD through the 96 way connector. INTRODUCTION This Technical Note describes the evaluation board for the AD7472 12-bit, high speed, low power, successive approximation A/D converter that operates from a single 2.7 V to 5.25 V supply. Full data on the AD7472 is available in the AD7472 data sheet available from Analog Devices and should be consulted in conjunction with this Technical Note when using the Evaluation Board. On-board components include an AD780 which is a pin programmable +2.5 V or +3 V ultra high precision bandgap reference, two AD797 op-amps used to buffer the analog input, and an OP07 op-amp used to buffer the DC bias voltage applied to the optional analog input bias-up circuit. There are various link options which are explained in detail on page 2. When using the board as a stand alone unit or with the HSCINTERFACE BOARD, external supplies must be provided. This evaluation board has five power supply inputs: VDD, AGND, VSS, VDRIVE and DGND. +5 V must be connected to the VDD input to supply the AVDD and DVDD pins on the AD7472, the AD780 voltage reference, the positive supply pin of all three op-amps and the digital control logic. 0 V is connected to the AGND input. -5 V must be connected to the VSS input to supply the negative supply pins on all three op-amps. The VDRIVE input can be used to provide an external voltage for the output drivers on the AD7472. If an external VDRIVE is supplied, it is referenced to the DGND input which should be tied to 0 V. The supplies are decoupled to the relevant ground plane with 47µF tantalum and 0.1µF multilayer ceramic capacitors at the point where they enter the board. The supply pins of the op-amps and reference are also decoupled to AGND with a 10µF tantalum and a 0.1µF ceramic capacitor. The AD7472 AVDD supply pin is decoupled to AGND with 10uF tantalum and 0.1µF multilayer ceramic capacitors. The AD7472 DVDD and VDRIVE pins are decoupled to AGND with 10uF tantalum capacitors and to DGND with 0.1µF multilayer ceramic capacitors. Interfacing to this board is through a 96-way connector. This Extensive ground planes are used on this board to minimize 96-way connector is compatible with the EVAL-CONTROL the effect of high frequency noise interference. There are two BOARD which is also available from Analog Devices. ground planes, AGND and DGND. These are connected at one External sockets are provided for the CONVST input, location close to the AD7472. CLKIN input and the VIN inputs. FUNCTIONAL BLOCK DIAGRAM Unipolar Ain AD7472 ADC 40 pin H SC interface Vin Bipolar Ain D ata B u s Bias-up buffer C ontrol Lines R eference 96 Pin E v al-Control Board Interface Buffer Refin Power Supply Circuit C lock G e nerator C ircuits REV. A Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. One Technology Way, P.O. Box 9106, Norwood. MA 02062-9106, U.S.A. Tel: 617/329-4700 Fax: 617/326-8703 EVAL-AD7472CB Analog Input Section The analog input section of this evaluation board accommodates unipolar and bipolar signals. Unipolar signals within the AD7472 analog input signal range of 0 V - 2.5 V are connected via SK5. They are then buffered by the on-board buffer before being applied to the VIN pin of the AD7472. Bipolar signals are connected via SK3 and are biased up by the on-board biasup buffer circuit before being applied to the VIN pin of the AD7472. The input impedence of the bias-up circuit is 50W which is determined by the value of R7. The input impedence may be modified by removing/changing the value of R7. To obtain optimum performance from this evaluation board the use of an impedence matched, passive filter is recommended before the analog signal is applied to the evaluation board. For example, when using a 100KHz input tone, a 100KHz 50W filter from TTE (part number KC5-100K-15K-50/50-720B) is suitable. R8 Potentiometer (50Kohm) This variable resistor is used to trim the DC bias voltage applied to the optional analog input bias-up circuit. This bias voltage is factory preset to 1.25 V which biases a bipolar signal to swing around the midpoint of the analog input range (0 - 2.5 V). If any adjustment is required, the user can use the histogram window in the eval-board software to analyze the DC voltage variation while adjusting the trim pot. To view this properly, an analog input signal should not be applied to the board. Under normal operation this pot should not be adjusted as it is preset for optimum performance. LINK AND SWITCH OPTIONS There are 11 link options which must be set for the required operating setup before using the evaluation board. The functions of these options are outlined below. Link No. Function. LK1 This link is used to select the DC bias voltage to be applied to the optional Vin bias-up circuit. If the user is using the bias-up circuit, this link must be inserted which will apply the 2.7 V reference voltage to the bias-up circuit. This causes a bipolar signal (applied to the bipolar vin input socket) to be biased up around +1.25 V before it is applied to the AD7472 VIN pin. - see also LK10 (below) If the bias up circuit is not being used this link should be removed. LK2 This link must be in position "A" if external power supplies are being used. In this position the control logic is being powered by the voltage applied to the VDD input. When power is being supplied from the EVAL-CONTROL BOARD, this link can be moved to position "B" if the user wants to drive the control logic from a separate +5 V which is generated on the EVAL-CONTROL BOARD. LK3 This link option selects the source of the CLKIN input. When this link is in position "A" the CLKIN input is provided by the EVAL-CONTROL BOARD. When this link is in position "B" the CLKIN input is provided via the on-board 25MHz oscillator. When this link is in position "C", an external CLKIN signal must be provided via SK1. When using the on-board generated burst clock, this link must be in position "D". LK4 This link option selects the source of the CONVST input. When this link is in position "A" the CONVST input is provided by the EVAL-CONTROL BOARD. When this link is in position "B" the CONVST input is provided via the external socket, SK2. LK5 This link option selects the source of the RD input. When this link is in position "A" the RD input is provided by the EVAL-CONTROL BOARD. When this link is in position "B" the RD input is tied to GND. This option must be selected while using the High Speed Converter Interface Board. LK6 This link option selects the source of the CS input. When this link is in position "A" the CS input is provided by the EVAL-CONTROL BOARD. When this link is in position "B" the CS input is tied to GND. This option must be selected while using the High Speed Converter Interface Board. LK7 This link option sets the voltage applied to the VDRIVE pin on the AD7472. When this link is in position "A", VDRIVE is connected directly to the DVDD pin. When this link is in position "B", an external voltage must be applied to the VDRIVE pin Via J3. LK8 This link selects the source of the VDD supply. When this link is in position "A" VDD must be supplied from an external source via J2. When this link is in position "B" VDD is supplied from the EVAL-CONTROL BOARD. LK9 This link selects the source of the VSS supply. When this link is in position "A" VSS must be supplied from an external source via J2. When this link is in position "B" VSS is supplied from the EVAL-CONTROL BOARD. LK10 This link must be in position "A" if a bipolar AIN signal is being applied to the bipolar Vin socket, SK3. This link must be in position "B" if a unipolar AIN signal is being applied to the unipolar Vin socket, SK5 Continued on next page –2– REV. A EVAL-AD7472CB LK11 This link is used to provide a clock signal path to the burst mode circuit generator from either the on-board clock oscillator or from an extermnal clock source via SK1. In position "A" the master clock signal is provided from the on-board crystal oscillator. In position "B" the master clock signal must be provided from an external source via SK1. SET-UP CONDITIONS Care should be taken before applying power and signals to the evaluation board to ensure that all link positions are as per the required operating mode. Table I shows the position in which all the links are set when the evaluation board is sent out. All links are set for use with the EVAL-CONTROL BOARD. Table I. Initial Link and Switch Positions Link No. Position Function. LK1 Inserted Provides DC bias voltage to the analog bias-up circuit. LK2 A The digital logic circuitry is powered from the same voltage as the AD7472. LK3 A CLKIN signal is provided by the EVAL-CONTROL BOARD via J1. LK4 A CONVST signal is provided by the EVAL-CONTROL BOARD via J1. LK5 A RD signal is provided by the EVAL-CONTROL BOARD via J1. LK6 A CS signal is provided by the EVAL-CONTROL BOARD via J1. LK7 A AD7472 VDRIVE pin is connected to the AD7472 DVDD pin. LK8 B VDD LK9 B VSS is supplied by the EVAL-CONTROL BOARD via J1. LK10 A The AD7472 Vin pin is connected to the output of the bias-up circuit. LK11 A Master clock for burst clock generator is provided from the on-board clock oscillator. REV. A is supplied by the EVAL-CONTROL BOARD via J1. –3– EVAL-AD7472CB EVAL-CONTROL BOARD INTERFACING Table II. 96-Way Connector Pin Functions. Interfacing to the EVAL-CONTROL BOARD is via a 96way connector, J1. The pinout for the J1 connector is shown in Figure 2 and its pin designations are given in Table II. ROW A ROWB ROWC 1 1 32 A B C 32 1 96-Way Connector Pin Description SCLK0 D0 3 D1 4 Figure 2. Pin Configuration for the 96-Way Connector, J1 D0-D11 2 DGND DGND 5 D2 6 D3 DGND Data Bit 0 to Data Bit 11. Three-state TTL outputs. D11 is the MSB. 7 SCLK0 D4 SCLK0 8 +5VD +5VD +5VD Serial Clock Zero. This continuous clock can be connected to the CLKIN pin of the AD7472 via LK3. 9 RD D5 10 D6 11 D7 CS +5VD Digital +5 V supply. This can be used to provide a separate +5 V supply for the digital logic if required via LK2. 13 D8 RD Read. This is an active low logic input connected to the RD pin of the AD7472 via LK5. 14 D9 CS 15 D10 Chip Select. This is an active low logic input connected to the CS pin of the AD7472 via LK6. 16 DGND DGND DGND FL0 Flag zero. This logic input is connected to the CONVST input of the AD7472 via LK4. 17 FL0 D11 IRQ2 18 IRQ2 Interrupt Request 2. This is a logic output and is connected to the BUSY logic output on the AD7472. 20 DGND DGND DGND 21 AGND AGND AGND 22 AGND AGND AGND 23 AGND AGND AGND 24 AGND AGND AGND 25 AGND AGND AGND 26 AGND AGND AGND DGND AGND 12 DGND DGND DGND 19 Digital Ground. These lines are connected to the digital ground plane on the evaluation board. It allows the user to provide the digital supply via the connector along with the other digital signals. Analog Ground. These lines are connected to the analog ground plane on the evaluation board. 27 AGND AGND AVSS Negative Supply Voltage. This provides a negative supply to the on-board op-amps via LK9. 28 AVDD Positive Supply Voltage. This provides a positive supply to the op-amps, the reference, the AD7472 and the digital logic. 30 29 When interfacing directly to the EVAL-CONTROL BOARD, all power supplies and control signals are generated by the EVAL-CONTROL BOARD. However, due to the nature of the DSP interface on the EVAL-CONTROL BOARD, AD7472 sampling rates greater than 400 KHz are not supported when interfacing the EVAL-AD7472CB directly to the EVAL-CONTROL BOARD. To achieve sample rates greater than 400 KHz, the HSC-INTERFACE BOARD must be used. The HSC-INTERFACE BOARD is a board designed to interface between evaluation boards for high speed analog-to-digital converters and the EVAL-CONTROL BOARD. It can be ordered from Analog Devices through the normal channels using the part number "HSCINTERFACE BOARD". AGND AGND AGND AGND 31 AVSS AVSS AVSS 32 AVDD AVDD AVDD Note : The unused pins of the 96-way connector are not shown. –4– REV. A EVAL-AD7472CB HIGH SPEED CONVERTER (HSC) BOARD INTERFACING Interfacing to the HSC BOARD is via a 40-way connector, J4. The pinout for the J4 connector is shown in Figure 3 and its pin designations are given in Table III. Pin No. Function Pin No. Function 1 D11 2 GND 3 D10 4 GND 5 D9 6 GND 7 D8 8 GND 9 D7 10 GND 11 D6 12 GND 13 D5 14 GND 15 D4 16 GND BUSY. This is a logic output and is connected to the BUSY logic output on the AD7472 via an inverting buffer. 17 D3 18 GND 19 D2 20 GND Ground. These lines are connected to the digital ground plane on the evaluation board. 21 D1 22 GND 23 D0 24 GND 25 N/C 26 GND 27 N/C 28 GND 29 N/C 30 GND 31 N/C 32 GND 33 BUSY 34 GND 39 1 40 2 Figure 3. Pin Configuration for the 40-pin HSC Interface Connector, J1 40-Way Connector Pin Description D0-D11 BUSY GND Table III. HSC Interface Connector Pin Functions. Data Bit 0 to Data Bit 11. Three-state TTL outputs. D11 is the MSB. When interfacing to the High Speed Converter Interface board, all required power supplies must be supplied from external sources via the power terminal, J2. The CLKIN signal can be generated on-board (using the crystal oscillator or the burst clock generator circuit) or provided externally via SK1. 35 N/C 36 GND The RD and CS inputs to the AD7472 must all be tied low using LK5 and LK6 respectively. 37 N/C 38 GND The CONVST signal must be provided externally via SK1. 39 N/C 40 GND Due to the 25 MHz on-board crystal (not the maximum of 26 MHz as specified in the datasheet) the throughput rate will not meet the maximum datasheet specification of 1.5 MSPS. N/C = Not Connected. Refer to the documentation included with the HSC-INTERFACE BOARD for more information. Note, the HSCINTERFACE BOARD was designed for other high speed ADC devices but it is compatible with the AD7472 evaluation system. REV. A –5– EVAL-AD7472CB SOCKETS OPERATING WITH THE EVAL-CONTROL BOARD There are four input sockets relevant to the operation of the AD7472 on this evaluation board. The function of these sockets is outlined in Table IV. The evaluation board can be operated in a stand-alone mode or operated in conjunction with the EVAL-CONTROL BOARD (with or without the HSC-INTERFACE BOARD). This EVAL-CONTROL BOARD is available from Analog Devices under the order entry "EVAL-CONTROL BOARD". When interfacing directly to this control board, all supplies and control signals to operate the AD7472 are provided by the EVAL-CONTROL BOARD when it is run under control of the AD7472 software which is provided with the AD7472 evaluation board package. This EVAL-CONTROL BOARD will also operate with all Analog Devices evaluation boards which end with the letters CB in their title. Table IV. Socket Functions Socket Function SK1 Sub-Miniature BNC Socket for external clock input. SK2 Sub-Miniature BNC Socket for external CONVST input. SK3 Sub-Miniature BNC Socket for Bipolar analog input The AD7472 can only accept analog inputs in the range 0 V to REFIN. Bipolar analog inputs in the range -1.25 V to +1.25 V applied to this socket are biased up to the acceptable AD7472 input range by the onboard bias-up circuit before being applied to the AD7472 VIN pin. SK5 Sub-Miniature BNC Socket for unipolar analog input. Analog inputs in the acceptable AD7472 analog input range (0 V to REFIN) are applied to this socket. The signal is then buffered before it is applied to the AD7472 VIN pin. CONNECTORS There are four connectors on the AD7472 evaluation board as outlined in Table V. Table V. The 96-way connector on the EVAL-AD7472CB plugs directly into the 96-way connector on the EVAL-CONTROL BOARD. No power supplies are required in the system. The EVAL-CONTROL BOARD generates all the required supplies for itself and the EVAL-AD7472CB. The EVAL-CONTROL BOARD is powered from a 12 V AC transformer. This is a standard 12 V AC transformer capable of supplying 1 A current and is available as an accessory from Analog Devices under the following part numbers: EVAL-110VAC-US: For use in the U.S. or Japan EVAL-220VAC-UK: For use in the U.K. EVAL-220VAC-EU: For use in Europe These transformers are also available for other suppliers including Digikey (U.S.) and Campbell Collins (U.K.). Connection between the EVAL-CONTROL BOARD and the serial port of a PC is via a standard RS-232 cable which is provided as part the EVAL-CONTROL BOARD package. Please refer to the manual which accompanies the EVAL-CONTROL BOARD for more details on the EVALCONTROL BOARD package. Connector Functions Connector Function J1 96-Way Connector for EVAL-CONTROL BOARD interface connections. J2 External VDD, VSS & AGND power connector. J3 External VDRIVE & DGND power connector. J4 40-Way Connector for HIGH SPEED CONVERTER INTERFACE BOARD connections. –6– REV. A EVAL-AD7472CB Figure 4. Main Screen SOFTWARE DESCRIPTION Included in the EVAL-AD7472CB evaluation board package is a PC-compatible disk. This disk has two sub-directories called EVAL_CTRL and HSC_INT, each containing software for controlling and evaluating the performance of the AD7472 when it is operated with the EVAL-CONTROL BOARD or the HSC-INTERFACE BOARD. The EVALAD7472CB Demonstration/Evaluation Software runs under DOS 4.0 or later and requires a minimum of a 386-based machine with 400kB of base RAM and 500kB of free hard disk space. The user interface on the PC is a dedicated program written especially for the AD7472. The disk which accompanies the EVAL-AD7472CB contains two sub-directories. The user should create a new directory on the main PC drive and label this "AD7472". Then, the sub-directories (and all files contained within them) on the EVAL-AD7472CB disk should be copied into this directory. The Mouse Driver on the PC should be enabled before running the software. If this has not been loaded, the program will not run. To run the software, simply make the AD7472\EVAL_CTL directory or the AD7472\HSC_INT directory (depending on which setup is being used) the current directory and type "go". When the evaluation program starts, the user sees the screen shown on Figure 3 (without any FFT or scope waveforms). This is the main screen and it is divided into three parts. The top part provides the main control interface for the AD7472 evaluation software. The middle part of the main screen functions as a Digital Storage Oscilloscope and the bottom part of the main screen operates as either a Digital Spectrum Analyzer or a Histogram analyzer. Each part of the screen has several buttons that can be pressed by using the mouse or the keyboard. To press a button using the mouse, simply use it to move the on-screen pointer to the button to be activated and click. To use the keyboard, simply REV. A press the appropriate key as highlighted on the button. Lower case letters must be used. When a button is pressed, it is highlighted on the screen. The next button can be highlighted by using the Tab key or the previous button by holding down the shift key and the Tab key together. The highlighted button can also be pressed by pressing the space bar. Pressing the ESC key halts any operation currently in progress. In this document, if a button can be activated from the keyboard then the key used is shown in bold in the button name. For example, "no prog" has the "p" highlighted in bold, indicating that the button can be activated by pressing the p key. Some buttons have a red indicator. A red indicator on the button means that the function associated with that button is on. Absence of the red indicator light means that the function associated with the button is off. The on/off status of these buttons is changed simply by selecting the button. Setting up the EVAL-CONTROL BOARD When the software is run, the "F2 Setup" button in the top left of the screen should be selected to pop up the setup menu (see fig. 4). This menu sets up the EVAL-CONTROL BOARD for use with the EVAL-AD7472CB. Firstly, a configuration file must be chosen. The configuration file contains the default configuration information for the EVAL-CONTROL BOARD, the Digital Spectrum Analyzer and the Digital Storage Oscilloscope. It also tells the AD7472.EXE software which .HIP file to download to the ADSP-2111. The .HIP file contains the DSP code which is executed by the ADSP-2111. Normally, the "no prog" button is off, so when the configuration file is loaded, the .HIP file is automatically downloaded to the ADSP-2111. However, if the "no prog" button is on, then the .HIP file is not downloaded to the ADSP-2111. –7– EVAL-AD7472CB saved in the "binary" format are for viewing purposes only. Use the mouse or the keyboard to highlight the configuration file and load it by clicking the "load" button. F6: Load. This allows the user to load data from a file with a .DAT extension. Only data that was saved as ints can be loaded and analyzed. A configuration file must be loaded via the "F2 Setup" menu before the data file can be analyzed. If there is no EVALCONTROL BOARD connected to the PC, then the "no prog" button in the "F2 Setup" menu must be on. Once a configuration file has been loaded, the data loaded from the .DAT file is analyzed according to the settings in the "F2 Setup" menu. Click the OK button to return to the main screen. F7: Reset. Choosing this option resets the EVAL-CONTROL BOARD. MAIN SCREEN F10: Quit. This quits the AD7472 evaluation software and returns control to the operating system. The "Analog in" section shows the analog input range and DC offset voltage. The user can then select the required number of samples and sampling frequency. Note: While the AD7472 data sheet specifies a maximum clock frequency of 26 MHz, the onboard crystal oscillator outputs a 25MHz clock. Therefore the max. sampling frequency will be less than that specified on the data sheet. An external clock frequency (up to the max specified on the data sheet) can be applied via the external socket, SK1. The top left part of the main screen contains eight buttons which are selected using the mouse or by using the function keys from the keyboard. These buttons and the actions they perform are: F1: Info. This button shows information on the software. F2: Setup. F3: Samp. When this key is pressed, the software causes the AD7472 to perform a number of conversions as determined by the setup menu (see above). The data from these conversions is then analyzed by the AD7472 evaluation software. Another set of samples may be taken by pressing the F3 key again. F4: Cont. Pressing this button causes the software to repeatedly perform conversions and analyze them. Once the conversions and analysis has been done for one set of samples, the software automatically repeats the process. It continues to do this until the ESC key is pressed. This button activates the setup menu. INFORMATION WINDOWS There are three information windows at the top of the main screen. The left-hand window is the configuration window and gives details about part being evaluated. It shows the name of the program that has been downloaded to the EVALCONTROL BOARD, the sampling frequency, the number of bits, the analog input range of the part and the output code format of the part. The right-hand large window is the Status window. This window provides feedback to the user as to what operations are currently being performed by the software and also displays error messages. Test Mode At the top right of the main screen are the Test Mode buttons. These buttons determine what sort of testing is done on the samples captured by the software. Both an ac analysis and dc analysis can be performed. The function of these buttons are: fft plot Choosing this button causes the Digital Spectrum Analyzer to appear at the bottom of the screen. Histogram: Choosing this button causes the Histogram Analyzer to be displayed at the bottom of the screen. There is one other button near the top of the screen, beside the "F10 Quit" button. This is: blackman-harris: When performing a Fourier transform of the sampled data, this button determines whether or not the data is windowed by a blackman-harris window before the transform. When this button is on, the data is windowed. When this button is off, the data isn't windowed. See the Digital Spectrum Analyzer section for more details. Figure 5. Setup Menu Screen F5: Save. This saves a set of samples to a file for use either at a later date or with other software. The samples can be saved either as "volts", "ints" or "binary". The format of all these files is ASCII text. Note that the AD7472 software can only load files saved in the "ints" format. Files saved in the "volts" and "ints" formats can be used with packages such as Mathcad. Files –8– REV. A EVAL-AD7472CB DIGITAL STORAGE OSCILLOSCOPE. When samples of data are captured, they are displayed on the Digital Storage Oscilloscope. If the blackman-harris button is turned on then the windowed data is also displayed on the oscilloscope. The 'scope has been designed to act in a similar way as a conventional oscilloscope. To the right of the oscilloscope are several buttons that control the manner in which data is displayed on the 'scope. The timebase for the oscilloscope is automatically chosen by the software if the Time/Div "Auto" button is on. The user can also select the timebase by clicking in the Time/Div window and scrolling up and down through the possible timebases. Similarly, the vertical scale of the oscilloscope is chosen automatically if the Volt/Div "Auto" button is on. The user also has the option of selecting the desired vertical scale in a similar manner to selecting the timebase. The other buttons associated with the oscilloscope are: grid This button toggles the grid display of the oscilloscope on and off. axis This button toggles the axis display of the oscilloscope on and off text This button toggles the text displayed on the oscilloscope screen on and off. line When the line button is on, the displayed samples are joined together by lines. When this button is off, the samples are displayed as points. ac When this button is on, the dc component of the sampled signal is removed and the signal is displayed. This has the effect of centering the signal vertically on the oscilloscope screen. When this button is off, the dc component is not removed and dual 1 2 the signal is displayed with its horizontal axis corresponding to a code of 0. The ac display option is useful for zooming in on a low-level signal that has a large dc offset. When the "dual" button is on, the oscilloscope screen is divided into two parts with the sampled data display centered on one horizontal axis and the windowed data display centered on another. When the "dual" button is off, both traces are centered on the same horizontal axis. This button toggles the sampled data trace on and off. This button toggles the windowed data trace on and off. HISTOGRAM ANALYZER The histogram analyzer counts the number of occurrences of each code in the captured samples and displays a histogram of these counts. The most frequently occurring code is displayed in the center of the histogram. The analyzer is normally used with a dc input signal and calculates the mean and the standard deviation of the sampled data. The mean and standard deviation are displayed in both volts and in units of the lsb size of the converter. The histogram gives a good indication of the dc noise performance of the ADC. The standard deviation shows directly the noise introduced in the conversion process. Figure 6 Histogram Screen REV. A –9– EVAL-AD7472CB Figure 7. AD7472 Evaluation Board Circuit Diagram (ADC Section) –10– REV. A EVAL-AD7472CB Figure 8. AD7472 Evaluation Board Circuit Diagram (Analog Input Bias-Up Section) Figure 9. AD7472 Evaluation Board Circuit Diagram (Burst Clock Generator Section). REV. A –11– EVAL-AD7472CB Table VI. Eval-AD7472CB Bill Of Materials Qty PartType RefDes Order Number Supplier/Manuf 11 1 3 11 11 1 1 5 1 2 1 10uF, 10V (TAJ-B Series) 10uF, 10V (TAJ-B Series) 0.1uF 16V X7R (0603 size) 0.1uF 50V X7R (0805 size) 0.1uF 50V X7R (0805 size) 27pF 25V X7R (0805 size) 1nF 50V NPO (0805 size) 47uF 16V (TAJ-D Series) 1uF 25V Y5V (0805 size) 22pF 100V NPO (0805 size) 4.7uF 16V (TAJ-B Series) C1 C3 C5 C9 C11 C13 C15 C17 C19 C21 C29 C7 C2 C4 C6 C8 C10 C12 C14 C16 C18 C20 C21 C42 C44 C45 C22 C23 C24 C26 C28 C30 C32 C34 C36 C37 C39 C25 C27 C31 C33 C35 C40 C43 C38 C46 C49 C41 FEC FEC FEC FEC FEC FEC 317-457 FEC 498-762 FEC 317-640 FEC-317-500 FEC 498-725 AVX AVX AVX AVX AVX AVX AVX AVX AVX AVX AVX 1 2 2 1 3 1 1 1 1 1 10W ±1% (0603 Size) 1KW ±1% (0805 Size) 100W ±1% (0805 Size) 100KW ±1% (0805 Size) 20KW ±1% (0805 Size) 75W ±1% (0805 Size) 130W ±1% (0805 Size) 130W ±1% (0805 Size) 390W ±1% (0805 Size) 50KW Multi-turn trimmer pot R1 R2 R3 R4 R14 R5 R6 R15 R16 R7 R11 R12 R17 R8 FEC FEC FEC FEC FEC FEC FEC FEC FEC FEC Multicomp Multicomp Multicomp Multicomp Multicomp Multicomp Multicomp Multicomp Multicomp Bourns 1 220uH Inductor (8RHB Series) L1 FEC 598-215 TOKO 1 1 2 1 1 1 1 1 1 1 1 4 2 AD7472ARU DM74LS14M AD797BN OP07DP AD780AN MM74HC04M MM74HC08M MM74HC161M DM74LS08M DM74ALS112M 25MHz TTL Output crystal 1N4148 Signal Diode SD103C Schottky Diode U1 U2 U3 U5 U4 U6 U7 U8 U9 U10 U11 Y1 D1 D2 D3 D4 D5 D6 AD7472BR FEC 527-361 AD797BN OP07DP AD780AN FEC 379-220 FEC 379-224 FEC 379-414 FEC 527-336 RS 857-430 FEC 177-414 FEC 368-118 ADI Fairchild ADI ADI ADI Motorola Motorola Motorola Fairchild Fairchild IQD Fairchild 1 9 1 11 36 1 1 1 1 4 2 pin header 4 (2+2) pin header 8 (4+4) pin header Shorting Link Ultra Low Profile Sockets 96 Pin 90º DIN41612 Plug 3 Pin Terminal Block 2 Pin Terminal Block 40 Pin 90º IDC Ribbon Connector Gold 50W SMB Jack LK1 LK2 LK4 LK5 LK6 LK7 LK8 LK9 LK10 LK11 LK3 LK1 - LK11 U3 U4 U5 U6 Y1 J1 J2 J3 J4 SK1 SK2 SK3 SK5 FEC FEC FEC FEC FEC FEC FEC FEC FEC FEC Harwin Harwin Harwin Berg Harwin Siemens Lumberg Lumberg 3M M/ACOM 1 PCB EVAL-AD7472CB Rev. A n/a –12– 498-660 498-660 499-675 499-687 499-687 910-995 911-239 911-732 911-471 771-491 771-200 771-235 771-235 911-185 348-144 511-705 511-791 511-780 528-456 519-959 269-931 151-786 151-785 727-714 310-682 n/a n/a REV. A EVAL-AD7472CB Figure 10. Component Side Artwork Figure 11. Solder Side Artwork REV. A –13– Figure 12. AD7472 Evaluation Board Component Placement Drawing (Component Side). Figure 13. AD7472 Evaluation Board Component Placement Drawing (Solder Side).