Innoswitch 3-pro Vout pin power supply

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According to the InnoSwitch3-Pro Family Datasheet:
1.The output voltage is regulated on the VOUT pin and defaults to 5 V at start-up.
2.When the VBUS switch is open (VBEN disabled), the system is reset to the default output voltage set point of 5 V. Disabling the series VBUS switch also resets all the programmable command registers to their default values.
3.uVCC normal current is 12 mA. Only at 5 V output, the uVCC pin can supply 48 mA maximum current for 0.5 seconds.

Q1>If the peripheral control MCU application needs more current supply, such as adding more peripheral chip and display, Doesn't use inside LDO of Innoswitch3-pro, Can use the Vout pin connected to a step-up 3V-24V switch power to 5V for MCU and display etc.?
Q2>When InnoSwitch3-Pro start-up, Vout defaults to 5V, The default current is?
Q3>InnoSwitch3-Pro uVCC pin keep floating?


Hi xionglinyang082,

Thank you for using Power Integrations products.
Answers to the questions are listed below:
A1> Yes. If external circuits require more power than internal LDO of InnoSwitch3-Pro can provide, a separate DC-DC power supply connected to the output voltage can be used. Make sure to connect the input of the DC-DC converter to the output bulk capacitors in the power section of the flyback converter, do not connect directly at the VOUT pin of the IC.
A2> Output current limit primarily depends on two things: the CC command register value and the current sense resistor Rsense used. Default value for the CC register is 128 decimal (please see Page 10-11 of InnoSwitch3-Pro datasheet) which corresponds to full-scale current, or 32mV across IS-GND pins of the IC. The resulting output current limit in Amperes is (32mV)/Rsense.
When CC register is written a different value (programmable from 25 to 128), output current limit in Amperes would be:
A3> Floating uVCC pin is not recommended. Please connect 2.2uF bypass capacitor to GND.