Hey guys,
I used the LinkSwitch-TN LNK306 by Power Integrations to create a 5.0V power rail on my PCB. (120VAC input). I used the datasheet to come up with the component values, and looked at other example circuits on the net that also used this IC.
The problem is that I am getting a 10.4V output instead of the desired 5.0V. I double checked the feedback resistors, and they are 2K and 3.84K which should generate the desired 5.0V output. I did an experiment and swapped out the 3.84K resistor with another 2K resistor and nothing changed. I also wanted to note that I have a 3.3V linear voltage regulator and a microcontroller connected up to the 5V power, so there should be a small current load on the circuit.
I am at a complete loss on how I should go about troubleshooting this circuit. I keep going over the circuit schematic, layout, and chosen components, and cannot find anything wrong. Any help would greatly be appreciated. I attached my circuit schematic, and the PCB layout of the circuit for reference.
Here are the part #'s I am using for the Inductors, Diodes, and Capacitors for reference as well:
D1, D3: DFLU1400-7
D2: US1JHE3/61T
D4: FM4007W-W
L1, L2: 46105C
C4: GRM219R61E106KA12D
C6, C7: 475CKE450MLN
C8: 35ZLH100MEFC6.3X11
R3: WP2S-7R5JA25
I used the LinkSwitch-TN LNK306 by Power Integrations to create a 5.0V power rail on my PCB. (120VAC input). I used the datasheet to come up with the component values, and looked at other example circuits on the net that also used this IC.
The problem is that I am getting a 10.4V output instead of the desired 5.0V. I double checked the feedback resistors, and they are 2K and 3.84K which should generate the desired 5.0V output. I did an experiment and swapped out the 3.84K resistor with another 2K resistor and nothing changed. I also wanted to note that I have a 3.3V linear voltage regulator and a microcontroller connected up to the 5V power, so there should be a small current load on the circuit.
I am at a complete loss on how I should go about troubleshooting this circuit. I keep going over the circuit schematic, layout, and chosen components, and cannot find anything wrong. Any help would greatly be appreciated. I attached my circuit schematic, and the PCB layout of the circuit for reference.
Here are the part #'s I am using for the Inductors, Diodes, and Capacitors for reference as well:
D1, D3: DFLU1400-7
D2: US1JHE3/61T
D4: FM4007W-W
L1, L2: 46105C
C4: GRM219R61E106KA12D
C6, C7: 475CKE450MLN
C8: 35ZLH100MEFC6.3X11
R3: WP2S-7R5JA25