Delta Electronics Series DNS Design Considerations CON, Features Descriptions, Remote On/Off

DESIGN CONSIDERATIONS (CON.)

The power module should be connected to a low ac-impedance input source. Highly inductive source impedances can affect the stability of the module. An input capacitance must be placed close to the modules input pins to filter ripple current and ensure module stability in the presence of inductive traces that supply the input voltage to the module.

Safety Considerations

For safety-agency approval the power module must be installed in compliance with the spacing and separation requirements of the end-use safety agency standards.

For the converter output to be considered meeting the requirements of safety extra-low voltage (SELV), the input must meet SELV requirements. The power module has extra-low voltage (ELV) outputs when all inputs are ELV.

The input to these units is to be provided with a maximum 6A time-delay fuse in the ungrounded lead.

FEATURES DESCRIPTIONS

Remote On/Off

The DNS series power modules have an On/Off pin for remote On/Off operation. Both positive and negative On/Off logic options are available in the DNS series power modules.

For positive logic module, connect an open collector (NPN) transistor or open drain (N channel) MOSFET between the On/Off pin and the GND pin (see figure 34). Positive logic On/Off signal turns the module ON during the logic high and turns the module OFF during the logic low. When the positive On/Off function is not used, leave the pin floating or tie to Vin (module will be On).

For negative logic module, the On/Off pin is pulled high with an external pull-up 5kΩ resistor (see figure 35). Negative logic On/Off signal turns the module OFF during logic high and turns the module ON during logic low. If the negative On/Off function is not used, leave the pin floating or tie to GND. (module will be On)

Vin Vo

ION/OFF

On/OffRL

Q1

GND

Figure 34: Positive remote On/Off implementation

Vin Vo

Rpull-

up

ION/OFF

On/OffRL

Q1

GND

Figure 35: Negative remote On/Off implementation

Over-Current Protection

To provide protection in an output over load fault condition, the unit is equipped with internal over-current protection. When the over-current protection is triggered, the unit enters hiccup mode. The units operate normally once the fault condition is removed.

DS_DNS04SIP06A_07172008

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