Rainbow Electronics LM3813 - Manual (Page 13)

TABLE 2. Duty Cycle to Current Conversion Table
Duty Cycle
(%)
Sense Current
(Amps)
Duty Cycle
(%)
Sense Current
(Amps)
95.5 0.990 50.0 -0.000
92.5 0.935 47.5 -0.055
90.0 0.880 45.0 -0.110
87.5 0.825 42.5 -0.165
85.0 0.770 40.0 -0.220
82.5 0.715 37.5 -0.275
80.0 0.660 35.0 -0.330
77.5 0.605 32.5 -0.385
75.0 0.550 30.0 -0.440
72.5 0.495 27.5 -0.495
70.0 0.440 25.0 -0.550
67.5 0.385 22.5 -0.605
65.0 0.330 20.0 -0.660
62.5 0.275 17.5 -0.715
60.0 0.220 15.0 -0.770
57.5 0.165 12.5 -0.825
55.0 0.110 10.0 -0.880
52.5 0.055 7.5 -0.935
50.0 0.000 5.0 -0.990
*Maximum Sense Current = 1.0 Amps for LM3812-1.0 and LM3813-1.0.
The sense current should be multiplied by 10 for LM3812-7.0 and LM3813-7.0.
Timing Diagram
10012211
Duty cycle of the PWM waveform during any sampling interval indicates the current magnitude (average) and direction during the previous sampling interval.
FIGURE 9. Typical Timing Diagram for Mostly Positive Current
LM3812/LM3813
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