Wizard - Outputs

In the Outputs sheet specify the voltage and current required from each of the supply's outputs. The following controls are available:

• Add... - click to  add a new output.

• Remove - click to remove the selected output.

• Edit... -  click to edit the selected output.

• Peak Loads  - select if you wish to design the supply for peak loads.

• LED Driver - changes the Operation Mode to CV/CC to design LED driver power supply.

• Total Peak Power - displays the cumulative peak power. If the Peak Loads check box is selected and you have added at least two outputs, you can click the calculator icon to enter the total peak power that the supply is expected to deliver.

• Continuous Power - displays the cumulative power of the specified outputs.

• Operation Mode - select whether the design operates in CV Only (Constant Voltage) mode, CV/CC (Constant Voltage/Constant Current) mode, or in CC Only (Constant Current) mode. Use the CV/CC mode if the supply is a battery charger or requires fixed output current limit.

• CC Threshold - for CV/CC mode specify the threshold voltage at which the supply enters CC mode. Click the calculator icon to type a custom threshold value.

Note: For LinkSwitch-PH and LinkSwitch-PL families you only can add a single output.

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Adding Outputs

To specify an additional output, click Add.... PI Expert allows up to six DC outputs to be specified. The main output must have a positive voltage. A negative voltage is only allowed for one output and must not be the main output.

When the Peak Loads check box is selected you need to specify the Peak Load values: output current and current duty cycle. The current duty cycle is important because it affects average primary current and thus core selection, turns ratio, output diode and other components and operating parameters. The duty cycle is also important when considering thermal constraints of the system including, device, transformer and output diodes.

In the Output Voltage Tolerance group you can enter a target output voltage tolerance either by percent or by entering the absolute values. Do this by clicking the calculator icon next to your desired tolerance specification. The output voltage tolerance is considered during multiple output optimization and can affect the choice of transformer core (primarily due to winding window area), turns ratio and output diode. Entering very tight output voltage tolerances, can result in a failure to optimize your design.

Note: For LinkSwitch-PH and LinkSwitch-PL families you only can add a single output.

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Editing Outputs

To edit an output:

1. Select the output you wish to edit by clicking anywhere in its row.

2. Click Edit... or double-click anywhere in the output row.

3. Make the desired changes to the output and then click OK.

PI Expert calculates the power for that output based on the voltage and current entered.

Depending on the settings specified in User Preferences, New Design Defaults, click Finish to create the design,  Next to move to the next Wizard screen, or Prev to move to the previous screen if required.

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