AD7008 CMOS DDS Modulator

AD7008Controlling the AD7008/PCBThe AD7008/PCB is designed to allow control (frequencyspecification, reset, etc.) through the parallel printer port of astandard IBM-compatible PC. The user simply disconnects theprinter cable from the printer and inserts it into edge connectorP1 of the evaluation board.The printer port provides information to the AD7008/PCBthrough eight data lines and four control lines. Control signalsare latched on the AD7008/PCB to prevent problems with longprinter cables.NameC36DRPFP1123456789101112131415161718192021222324252627282930313233343536LATCHD0D1D2D3D4D5D6D7RESETLOADWRD0D1D2D3D4D5D6D72345678910LATCHRESETLOADWR10k10PB+5RZ14.7k6PB+5RZ223456INPUTS/OUTPUTSDescriptionSMBFSELECTSMBCLKSMBSDATAXTAL114V CC8OUTV EEP136-pin edge connector to connect to parallelport of PC.CLOCK CMOS input for clock R6 provides termination.FSEL CMOS input to select between Freq 0 and Freq 1.Low selects Freq 0.SDATA CMOS input for serial input pin.SCLK CMOS input for clocking in SDATA.I OUTAnalog output.I OUT N Complementary analog output.V REFTest point for V REF pin.P2+5 V and ground power connection.LK1External sleep command input.R310k+5VC90.1µFSMBSCLKR650OPTIONALR210k7R110kD0D1D2D3D4D5D6D7LWRD0D1D2D3LLOADH3MLK1RESET123+5VGND19202122232425268910111213141516273233343536414231303837D0D1D2D3D4D5D6D7D8D9D10D11D12D13D14D15WRCSTC0TC1TC2TC3LOADRESETSLEEPFigure 36.A 3.5" floppy disk containing software to control the AD7008 isprovided with the AD7008/PCB. This software was developedusing C. The C source code is provided in a file namedA:\AD7008.C, which the user may view, run, or modify.An executable version of this software is also provided, and canbe executed from DOS by typing “A:\AD7008.” The softwareprompts the user to provide the necessary information neededby the program. Additional information is included in a test filenamed A:\readme.txt.A windows 3.1 executable called WIN7008 is also included.U1DUT7008PSCLKSDATAFSELECTCLKV REFCOMPAGNDDGNDDGNDDGNDDGNDTEST653172839447182943400.048 (1.21)0.042 (1.07)0.020(0.50)R+5V+5V+5V+5V+5V U2474HC74PRLOAD 2 5D Q LLOAD3> CCLQ61+5V+5V10 U274HC7412 PR 9WR D Q L11WRLATCH> CCLQ813+5VOUTLINE DIMENSIONSDimensions shown in inches and (mm).44-Pin PLCC (P-44A)671718C70.1µFV REFC6R40.1µF50+5VI OUTI OUT21SMBR5I OUT504FSADJFSADJUST390+5VDV AAV DDV DDV DD0.048 (1.21)0.042 (1.07)PIN 1IDENTIFIERTOP VIEW(PINS DOWN)0.656 (16.66)0.650 (16.51) SQ0.695 (17.65)0.685 (17.40) SQP2PCTB2120.056 (1.42)0.042 (1.07)40392928C20.1µFSMBI OUTC30.1µF0.180 (4.57)0.165 (4.19)C40.1µFC110µF0.110 (2.79)0.085 (2.16)0.025 (0.63)0.015 (0.38)0.050(1.27)BSCC50.1µFC80.1µF0.021 (0.53)0.013 (0.33)0.032 (0.81)0.026 (0.66)0.040 (1.01)0.025 (0.64)+5V0.63 (16.00)0.59 (14.99)PRINTED IN U.S.A. C1791a–10–2/95–16–REV. B