of Microprocessors

+4
+3
+2
+1
0
-I
-2
-3
-4
AMPLITUDE (dBI
DAC RESPDNSE /
/COMPENSATOR RESPONSE
COMPENSATED
RESPONSE
-6
-8
-10
-12
-14
-16
-18
-2D
0.1 0.15 0.2
(AI
0.3 0.4 0.5 0.6 08 1.0 I. 2 I. 5 2.0
(AI
3.0 4.0 5.0 6.0 8.0 10.0
NORMALIZED FREQUENCY
10 REM PROGRAM TO AID IN THE DESIGN OF 2-POLE COMPENSATION FILTERS FOR DACS
11 REM USING FINITE OUTPUT PULSE WIDTHS AND TIME CONSTANT LIMITED DEGLITCHERS.
20 REM IN STATEMENTS 101-105, SET THE VARIABLES AS FOLLOWS:
21 REM F1 = SAMPLE RATE AS A MULTIPLE OF THE MAIN FILTER'S CUTOFF FREOUENCY
22 REM TO = DAC OUTPUT PULSE WIDTH AS A FRACTION OF THE SAMPLE PERIOD
23 REM T1 = DEGLITCHER TIME CONSTANT AS A FRACTION OF THE SAMPLE PERIOD
24 REM FO = RESONANT FREQUENCY OF PROPOSED COMPENSATION FILTER
25 REM QO = RESONANT Q OF PROPOSED COMPENSATION FILTER
26 REM N = NUMBER OF FREQUENCY POINTS TO EVALUATE AND PRINT
30 REM WHEN RUN, THE PROGRAM PRINTS THE NORMALIZED FREOUENCY BETWEEN 0.1 AND
31 REM 10 TIMES THE MAIN FILTER CUTOFF FREOUENCY ON A LOG SCALE AND THEN FOR
32 REM EACH FREQUENCY, THE RAW DAC OUTPUT AMPLITUDE INCLUDING SIN(X)/X AND
33 REM DEGLITCHER TIME CONSTANT LOSSES, THE COMPENSATION FILTER GAIN, AND THE
34 REM PRODUCT OF THE TWO WHICH IS THE COMPENSATED DAC OUTPUT.
101 F1=2. 50
102 TO=1.0
103 T1=0.1
104 FO=1.58
105 QO=1.45
106 N=100
200 F2=F1/(6.283*T1): REM NORMALIZED 3DB DOWN POINT OF DEGLITCHER
201 F3=FI/TO: REM NORMALIZED FREQUENCY OF FIRST SIN(X)/X NULL
210 F=O.I: REM INITIAL STARTING FREOUENCY
220 PRINT "FREQUENCY";TAB(l5);"DAC OUTPUT";TAB(30);"COMP. GAIN";TAR(45);
221 PRINT "COMPOSITE"
230 F=O.I: REM INITIAL FREQUENCY
300 A=ABS(SIN(3.14159*F/F3)/(3.14159*F/F3)): REM SIN(X)/X LOSS
301 A=A*((F2/F)/SOR(I+(F2/F)t2)): REM DEGLITCHER ADDITIONAL LOSS
310 G=SQR(I/((F/FO)t4+(F/FO)t2*(1/QOt2-2)+I)): REM COMP FILTER GAIN
320 R=A*G: REM COMPOSITE CORRECTED OUTPUT
400 PRINT F;TAR(15);A;TAB(30);G;TAB(45);R
500 F=F*10 (2/N)
510 IF F