Delta Electronics Series DNS manual Feature Descriptions CON, Voltage Margining, Voltage Tracking

margin-down

FEATURE DESCRIPTIONS (CON.)

The amount of power delivered by the module is the voltage at the output terminals multiplied by the output current. When using the trim feature, the output voltage of the module can be increased, which at the same output current would increase the power output of the module. Care should be taken to ensure that the maximum output power of the module must not exceed the maximum rated power (Vo.set x Io.max ≤ P max).

Voltage Margining

Output voltage margining can be implemented in the DNS modules by connecting a resistor, R margin-up, from the Trim pin to the ground pin for margining-up the output voltage and by connecting a resistor, Rmargin-down, from the Trim pin to the output pin for margining-down. Figure 39 shows the circuit configuration for output voltage margining. If unused, leave the trim pin unconnected. A calculation tool is available from the evaluation procedure which computes the values of R margin-upand

R for a specific output voltage and margin percentage.

The output voltage tracking feature (Figure 40 to Figure

42)is achieved according to the different external connections. If the tracking feature is not used, the TRACK pin of the module can be left unconnected or tied to Vin.

For proper voltage tracking, input voltage of the tracking power module must be applied in advance, and the remote on/off pin has to be in turn-on status. (Negative logic: Tied to GND or unconnected. Positive logic: Tied to Vin or unconnected)

PS1	PS1
PS2	PS2

Figure 40: Sequential Start-up

Vin Vo

On/Off Trim

Rmargin-down Q1

Rmargin-up

PS1	PS1
PS2	PS2

Rtrim Q2

GND

Figure 39: Circuit configuration for output voltage margining

Voltage Tracking

The DNS family was designed for applications that have output voltage tracking requirements during power-up and power-down. The devices have a TRACK pin to implement three types of tracking method: sequential start-up, simultaneous and ratio-metric. TRACK simplifies the task of supply voltage tracking in a power system by enabling modules to track each other, or any external voltage, during power-up and power-down.

By connecting multiple modules together, customers can get multiple modules to track their output voltages to the voltage applied on the TRACK pin.

DS_DNS04SIP06A_07172008

Figure 41: Simultaneous

	PS1	PS1
-ΔV	PS2	PS2

Figure 42: Ratio-metric

11