Datasheet

Analog Dimming With PWM Voltage Data
2-9
Setup and Test Results
2.9 Analog Dimming With PWM Voltage Data
For the Analog Dimming With PWM Voltage method, the EVM is configured
identically with the Analog Dimming With Analog Voltage method with the
exception that the control voltage is injected into the DIM2 pin on J3. R1 and
C2 are chosen to be 10 kΩ and 1 µF to adequately filter a 1-kHz control
voltage. Figure 2−6 shows how the PWM control voltage at the DIM2 pin on
J3 is converted into an equivalent analog voltage on the DIM1 pin on J3. The
graph of the output current versus the control voltage is identical to Figure 2−5
after the PWM control voltage is converted into its average dc equivalent.
Figure 2−6. PWM Control Converted to Analog Control Voltage
0.5 ms
0.5 V
0.5 ms
50 mV
50 mV
10 mV
0.2 V
2
3
4
1
BWL
DC x10
DC x10
DC
DC
x10
2 DC 0.24 V
100 kS/s
AUTO
1
0.5 ms
0.5 V
2