TC1025
FIGURE 4-4:
SQUARE WAVE GENERATOR
VDD
R1
100k
C1
TC1025
R4
VDD
–
1/2 TC1025
+
R2
100k
R3
100k
VH
=
R2 (VDD)
R2 + (R1||R3)
VL =
(VDD) (R2||R3)
R1 + (R2||R3)
FREQ =
1
2(0.694)(R4)(C1)
FIGURE 4-5:
PULSE WIDTH MODULATOR
VDD
VC
R6
10k
C1
R1
TC1025
100k
R4
1/2 TC1025
VDD
–
+
R2
100k
R3
100k
VH =
VDD (R1R2R6 + R2R3R6) + VC (R1R2R3)
R1R2R6 + R1R3R6 + R2R3R6 + R1R2R3
VL =
VDD (R2R3R6) + VC (R1R2R3)
R1R2R6 + R1R3R6 + R2R3R6 + R1R2R3
FREQ =
1
2 (0.694) (R4) (C1)
For Square Wave Generation
Select R1 = R2 = R3
VC =
VDD
2
© 2005 Microchip Technology Inc.
DS21656C-page 7