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# TPS62130A: The conversion efficiency is 20% different from that given on the official website

Part Number: TPS62130A

Hi，

When using TPS62130A, the conversion efficiency of my client is 20% different from that given in the manual. May I ask what causes this problem and how to improve and optimize it?

Detail：

1. The first way: input 5V, output 1.0V, the official website gives the conversion efficiency: 88.7%, the measured conversion efficiency: 68.48%

Test method: Remove the 0Ω of R20 and R21, connect the current probe in series, and use the oscilloscope to test the current value of the two positions: 146.71mA, 448.56mA, namely: η= (1.055 * 0.44856)/ (4.71 * 0.14671)= 68.48%.

2. The rest of the way is the same as the 1V0 conversion efficiency, such as:

The input is 4.71V, the output is 1.8V, the measured output current is 231mA, the measured conversion efficiency is 81.96%, and the value given by the official website is 91%.

The input is 4.71V, the output is 1.2V, the measured output current is 378mA, the measured conversion efficiency is 75.99%, and the value given on the official website is 90%.

3. Only 3.3V this way conversion efficiency is higher:

The input is 4.71V, the output is 3.3V, the measured output current is 207mA, the measured conversion efficiency is 96%, and the value given on the official website is 95%.

4. All of the above circuit device models are the same, as follows:

Cin_10uf----Murata: GRM188R61E106M

Cout_22uf----Taiyo yuden: LMK107BBJ226MA-T

L Inductance :2.2uH---- Wurth: 74438336022

• Hi Rhea!

1. Can you show me your setup of the website efficiency? Maybe the condition is different, such as loading, Fsw.

2. For efficiency test, it is better to use multi meter to read the current value.

Shuai

• Hi Shuai,

1. The conversion efficiency calculated by the recommended circuit provided by the official website design tool is shown as follows:

2. The official website design tool provides a recommended circuit. Manually set Cin\Cout\L1 as the model selected for our circuit design. The conversion efficiency calculated is as follows:

3, data manual input 5V output 0.9V conversion efficiency given as follows:

Thanks!

• Hi

It maybe the test issue.

1. For efficiency test, need to use high-accuracy multi meter to measure the input and output current, use multi meter to touch the voltage between the two terminal pad of C11 and C13.

2. Pls check the SW waveform, make sure the pulse is stable.

3. You can also take a look at : If you disable other rails, will the efficiency change?

Shuai