Trying to achieve 12V DC at 360mA in LNK306DN-Based Circuit

Dear Ezekiel,

I've made my part number selections based on your recommendations. Kindly review them to ensure they are suitable:

• L1: SRR7045-471M - I hope this inductor will fit, I need this footprint.

• R1: RMCF0603FT11K8

• R3: ERA-3AEB2491V

• LNK3207

• Regarding the input capacitor, I'm unsure about the minimum capacitance needed. I planned to use two 11uF capacitors in parallel. However, there's a height constraint on the PCB, and I'm having trouble finding capacitors with a height of 0.531 inches (13.50mm). Do you have any suggestions for capacitors that would meet this height requirement?

Thank you for your assistance.

Hi,

Thank you for using PI-Forums.

attach is a PIXLS for design. you can download it:

step1. right click then choose save link as then save.

step 2. open you PIEXPERT then Choose Open Design.

step 3. Upload the file to view the specs.

the design uses a LNK32x8 with reduced Current limit (Cbp = 1uF).

for L1 I based the specs from SRR7045-331.

for input Caps. you can search from AISHI. we have a cap from them the 10uf 400v that is 13.35mm in height.

regards,

Sigris

I would appreciate it if you could review the attached schematics.  unfortunately, I'm not achieving the desired output. I was expecting an output of 12 volts and 360mA, but I am only getting around 5 volts. I kindly request your assistance in addressing this issue.

Regards,

Ashiq k

+917034468209

I would appreciate it if you could review the attached schematics.  unfortunately, I'm not achieving the desired output. I was expecting an output of 12 volts and 360mA, but I am only getting around 5 volts. I kindly request your assistance in addressing this issue.

Regards,

Ashiq k

+917034468209

Hi,

Thank you for using PI-Forums.

base on your schematic, your design is very similar on the reference design. so it should work. you can add a 10 ohm resistor in series at c23. to make a rc filter to filter out unwanted noise on fb pin.

Fb pin ref Voltage is 2V. using voltage divider. 2V = Vout * (2.49kohms/(2.49kohm+11.8kohm)) >> Vout = 11.4779 V.

did you build the circuit or is it on simulation? 

we also have a RDR-912 which has 12V and 550mA output it uses a lnk3207 and closer to your desired output.

rdr-912_non-isolated_buck_converter_small_appliances_linkswitch-tn2.pdf (power.com).

regards,

Sigris.

Hello Team, 

I am designing the power supply using LNK306 power supply,  with specification of  5V, 360mA. Used the values for the components suggested by the PIxls software. Please go through the schematic attached with this post. I am also unable to get 5V at the output. Instead I am getting 3.1V at the output after implementing the 10E resistor in series with the capacitor  as you have suggested. 

I am also listing out the voltage I am getting between different test points.

Voltage at output = 3.1V

voltage between TP1 and TP3 = 1.8V.

Voltage between TP1 and Gnd = 4.8V.

Voltage between TP2 and Gnd = 6.2V.

Please suggest me the problem area and also provide the solution for the same.

Thanks you so much in advance.