Delta Electronics DNL Series manual PS1 PS2, Ratio-Metric Implementation

PS1

PS2

PS1

PS2

Figure 4: Sequential Power up

Figure 5: Sequential Power down

Ratio-Metric Implementation

Ratio–metric is implemented by the selection of the resistor values of the voltage divider on the TRACK pin. Resistors R1 and R2, in Figure 6 determine the tracking method that is implemented.

To simplify the tracking design, set the initial value of R2 equal to 20KΩ at internal circuit and adjust the resistor R1 for different tracking method. Figure 6 shows the circuit diagram of Ratio-Metric start-up when VoPS2 tracks the VoPS1.

Vin

ENABLE

PS1

Vin

VoPS1

R1

TRACK

ENABLE

PS2

To Tracking circuit

R2 20K

VoPS2

Figure 6. PS1 and PS2 track output voltage Ratio-Metric start-up

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