LM25118 Buck-Boost DCDC Power Module

**LM25118 automatic buck-boost non-synchronous [DCDC](https://blog.zeruns.tech/tag/DCDC/) power module, input voltage 4.5-35V, output voltage 1.23-31V adjustable, maximum output current 8A, maximum efficiency 92%, switching frequency 400kHz. ** **

[LM25118](https://blog.zeruns.tech/tag/LM25118/) is a 3-42V wide input voltage, current mode non-synchronous buck/boost controller. **

The school electrical competition training homework is to make a [power](https://blog.zeruns.tech/tag/电源/) module with an input of 5V, an output of 1.8-24V, and a maximum current of 2A, so I made a LM25118 power module, a non-synchronous [Buck-Boost](https://blog.zeruns.tech/tag/Buck-Boost/) circuit.

In the actual circuit, I changed the MOS tube model to NCE6050KA, because when the input is 5V, the voltage of the PWM wave output by LM25118 is only 3.8V, and the full conduction voltage of NCE7560K in the schematic diagram is 4V. Therefore, when using NCE7560K, the MOS tube will work in the linear region, which will cause abnormal output voltage, so I changed it to NCE6050KA, the full conduction voltage of this MOS tube is 3V.

I also changed the inductor to 6.8μH. In addition, the 2nd pin UVLO of the LM25118 chip in the physical picture below was not connected when the schematic diagram was drawn, so a wire flew up. The following PCB diagram and schematic diagram have been corrected.

If you need higher input and output voltages, you can replace the filter capacitor with a higher withstand voltage value and modify the resistance value of feedback resistors R9 and R10. The calculation formula is in the chip data manual.

LM25118 data sheet download address: [https://url.zeruns.tech/j2PjZ](https://url.zeruns.tech/j2PjZ)

- SY8205 synchronous buck adjustable DCDC power supply module (schematic diagram and PCB): [https://blog.zeruns.tech/archives/717.html](https://blog.zeruns.tech/archives/717.html)
- 2011 National Electric Competition Topic - Switching Power Supply Module Parallel Power Supply System: [https://blog.zeruns.tech/archives/718.html](https://blog.zeruns.tech/archives/718.html)

## Actual picture

![IMG_5737.jpg] ![IMG_5738.jpg]
## LM25118

IntroductionLM25118 The wide voltage range buck/boost switching regulator controller has all the functions required to implement a high performance and cost-effective buck/boost regulator with a minimum of external components. The buck/boost topology keeps the output voltage regulated when the input voltage is below or above the output voltage, making this device ideal for automotive applications. The LM25118 operates as a buck regulator when the input voltage is sufficiently greater than the regulated output voltage, and then gradually transitions to the respective buck/boost modes as the input voltage approaches the output voltage. This dual-mode approach maintains regulation over a wide input voltage range and provides the best conversion efficiency in buck mode while providing glitch-free output during mode transitions. The controller is easy to use and includes drivers for both the high-side buck MOSFET and the low-side boost MOSFET. The control method of the regulator is based on current mode control with an emulated current ramp. Emulated current mode control reduces the noise sensitivity of the pulse width modulation circuit to reliably control the very small duty cycles required in high input voltage applications. Other protection features include current limiting, thermal shutdown, and an enable input. The device is packaged in a power-enhanced 20-pin HTSSOP package with an exposed die pad for heat dissipation.

![image.png]
## Component Purchase Address

- 0805 Resistor Sample: [https://u.jd.com/DzK9k0O](https://union-click.jd.com/jdc?e=618%7Cpc%7C&p=JF8BAQoJK1olXQ8HU15UC0seAl8MGFgSVQYDUVpdCntTXDdWRGtMGENDFlVDFhNSVzMXQA4KD1heSlpeC0wfA24NH1sXQl9HCANtDileSmlKcyx2CFoAAjgVagpISxJve1cZbQcyVF9 cCUoQBGkKE2slXQEyFTBdCUseBmwAHWsUbQYFXVddDEoXBWgNGlglWgYLZFxdC0gSBG0BHkccWQcBV1dtOHsUM2gIEk8TL0dQQFgvOHsXM2w4G1oVVQUHU1peD0sLA28AHVsTQQYFXVddDEoXBGoK HlwlXwcDUFdtOHtJVQ57bVpNOl0DAg4PTShEYGd-GABQBwdsVh0YWjZjVyl3QFMdHmJdKiBVOA)
- 0805 capacitor sample: [https://s.click.taobao.com/cTZzzDu](https://s.click.taobao.com/t?e=m%3D2%26s%3DhCkyVTMlsSpw4vFB6t2Z2ueEDrYVVa64LKpWJ%2Bin0XLjf2vlNIV67mYU%2FNPSg%2Bdg2Y%2Bdtp35Zpp%2FmzaS0s2vXCsmIF0UHtujBkxkgN7jKg%2BiJaQjFxYBevWfPAv4x3d%2FOlGkMkr%2BSUUYmUGuVZn0uTy9VOuylv9Cy3DHLbLD2uai1jMNxDhLMiTdqMDI4bn8A7nVLE Nk%2FnZlhFvUJn%2BOzhZK2r696vOOyTOFiAFMpyWzUS0aYWefwPN%2F9EFFI74WPI3Gm%2FFlLz%2BRmfcD0XF1fkPzJbJmoAt0zD1Onw6Jz4MfDDpUuGnRj8Yl7w3%2FA2kb&union_lens= lensId %3APUB%401688150230%4021059d4c_0b3c_1890d984645_6a09%4001%40eyJmbG9vcklkIjo2MTM1NCwiic3BtQiiI6Il9wb3J0YWxfdjJfcGFnZXNfcHJvbW9fZ29vZHNfaW 5kZXhfaHRtIn0ie)
- LM25118芯片：[https://s.click.taobao.com/4FauRDu](https://s.click.taobao.com/t?e=m%3D2%26s%3DBYddxrS3r7Nw4vFB6t2Z2ueEDrYVVa64LKpWJ%2Bin0XLjf2vlNIV67t30717zSxH8xeoNewupcd5%2FmzaS0s2vXCsmIF0UHtujBkxkgN7jKg%2BiJaQjFxYBevWfPAv4x3d%2FOlGkMkr%2BSUUYmUGuVZn0uRDBbf95h6seTxpmwkkouzqi1jMNxDhLMnotgd7NXRy%2F3OppJwt5etg6FLpGlRDrKkHPFrIfAoyUqHHR%2BjPrDlRNczSu4LlfUBsVuPzPS2O%2FnZ%2FClaDLkUuMJi1gYBJvNFSsXCNd9EoxE59iYTGkDbWFi4V5KBpmMh5xSyDILJKT5hEffU0N%2Fc7GDmntuH4VtA%3D%3D&union_lens=lensId%3APUB%401688829972%402107d7dd_09ff_189361c4e9f_173c%4001%40eyJmbG9vcklkIjo2MTM1NCwiic3BtQiiI6Il9wb3J0YWxfdjJfcGFnZXNfcHJvbW9fZ29vZHNfaW5kZXhfaHRtIn0ie)
- NCE6050KA：[https://s.click.taobao.com/YgFKpDu](https://s.click.taobao.com/t?e=m%3D2%26s%3Dzchm4H135W9w4vFB6t2Z2ueEDrYVVa64LKpWJ%2Bin0XLjf2vlNIV67sETh803ZI6MoAgJVlbS%2FO9%2FmzaS0s2vXCsmIF0UHtujBkxkgN7jKg%2BiJaQjFxYBevWfPAv4x3d%2FOlGkMkr%2BSUUYmUGuVZn0uRDBbf95h6seTxpmwkkouzqi1jMNxDhLMnotgd7NXRy%2F3OppJwt5etgpaoEzcoKDZeo4Z7iDpKDIokXi1WiBPnwUTtCsSeQgLt4G4NpcfRODTbcJvYsX3s%2BMJi1gYBJvNFSsXCNd9EoxE59iYTGkDbWFi4V5KBpmMngs52bwCKI97571FH3sKUjGDmntuH4VtA%3D%3D&union_lens=lensId%3APUB%401688830066%402132f252_0af6_189361dbdf2_b4da%4001%40eyJmbG9vcklkIjo2MTM1NCwiic3BtQiiI6Il9wb3J0YWxfdjJfcGFnZXNfcHJvbW9fZ29vZHNfaW5kZXhfaHRtIn0ie)
- SBDD2045CT：[https://s.click.taobao.com/Le4KpDu](https://s.click.taobao.com/t?e=m%3D2%26s%3DD0mDt3F%2BHWtw4vFB6t2Z2ueEDrYVVa64LKpWJ%2Bin0XLjf2vlNIV67qCzgISnlsyu%2FpU2SWJU0cJ%2FmzaS0s2vXCsmIF0UHtujBkxkgN7jKg%2BiJaQjFxYBevWfPAv4x3d%2FOlGkMkr%2BSUUYmUGuVZn0uRDBbf95h6seTxpmwkkouzqi1jMNxDhLMnotgd7NXRy%2F3OppJwt5etifPRh7YVmrmZeRPUgf0T5Fea0IP%2FTPA9WdyQT6Z%2Bk1kElOUME9Wrgu%2Bp7i99ooE8eMJi1gYBJvNFSsXCNd9EoxE59iYTGkDbWFi4V5KBpmMjIbIBwYckQ3IM%2FBEHE4jL%2FGDmntuH4VtA%3D%3D&union_lens=lensId%3APUB%401688830155%40213e9074_0b0d_189361f194f_28d2%4001%40eyJmbG9vcklkIjo2MTM1NCwiic3BtQiiI6Il9wb3J0YWxfdjJfcGFnZXNfcHJvbW9fZ29vZHNfaW5kZXhfaHRtIn0ie)
- KF7.62端子座：[https://s.click.taobao.com/txVJpDu](https://s.click.taobao.com/t?e=m%3D2%26s%3DFm8j9ONS8Clw4vFB6t2Z2ueEDrYVVa64K7Vc7tFgwiHjf2vlNIV67oAHUuWKtxTnxT40F5yyh61%2FmzaS0s2vXCsmIF0UHtujBkxkgN7jKg%2BiJaQjFxYBevWfPAv4x3d%2FOlGkMkr%2BSUUYmUGuVZn0uUeNaL1L6rWLYVnYE523ghoLZMqoQW%2BfuKGzo1lVxIio6624ppBESMBDHp9u2zjbH4ZfikofVwgQTGH3aSojaG55%2FCh316%2B51KJ3tdsKcVinQsSSpN50Tf30oRXWDqY30GHQ7dFzkf%2BmfWsUjZoD5RBcNfAzIdweXd5Yt1EeUdanIYULNg46oBA%3D&union_lens=lensId%3APUB%401688830221%402108b7bd_1ab4_18936201e1a_c765%4001%40eyJmbG9vcklkIjo2MTM1NCwiic3BtQiiI6Il9wb3J0YWxfdjJfcGFnZXNfcHJvbW9fZ29vZHNfaW5kZXhfaHRtIn0ie)

**元器件购买推荐立创商城，优惠注册链接：[https://activity.szlcsc.com/invite/D03E5B9CEAAE70A4.html](https://activity.szlcsc.com/invite/D03E5B9CEAAE70A4.html)**

**板上所有元器件都可以在立创商城买到，在开源链接里的BOM表那点立即到立创商城下单可将用到的元器件一键导入到购物车。**

## 测试数据

### 输出带载测试

输入 12V，输出 31V时，空载电流 0.019A，空载功率 0.22W。

| 输入电压 | 输入电流 | 输入功率 | 输出电压 | 输出电流 | 输出功率 | 效率 |
| :------: | :------: | :------: | :------: | :------: | :--- ---: | :---: |
| 15.01V | 4.56A | 68.45W | 12.06V | 5A | 60.3W | 88% |
| 6.51V | 5.15A | 33.53W | 12.11V | 2A | 24.22W | 72.2% |
| 6.01V | 3.95A | 23.74W
| 1.81V | 8A | 14.48W | 61%
| 7.01V|4.32A|30.28W|23.89V|1A|23.89W|78.9%||
11.99V|2.19A|26.26W|23.13V|1A|23.13W|88.1%||
24.01V|1.62A|38.9W | 12.03V | 3A | 36.09W | 92.8% |
| 24.01V | 2.72A | 65.31W | 12.03V | 5A | 60.15W | 92.1% |
| 12V | 4.35A | 52.2W | 30.38V | 1.5A | 45.57W | 87.3% |
| 7.99V | 5.05A | 40.35W | 12.05V | 2.5A | 30.13W | 74.7% |

![ IMG_20230707_024630.jpg] ![IMG_20230707_024734.jpg]
### Ripple test

12V input, 5V output no load When the ripple is at 12V input and 5V 2A output, the ripple peak-to-peak value is about 8mV .

![12v input no-load.jpg] When the ripple
is at 12V input and 5V 2A output, the ripple peak-to-peak value is about 15mV.

![12v input.jpg]
When the ripple is at 6V input and 12V 1.5A output, the The peak-to-peak value of the ripple is about 230mV.

![6v input.jpg]
When the input is 12V and the output is 23V 1A, the peak-to-peak value of the ripple is about 300mV.

![12v input 24v output.jpg]
When 12V input and 24V output are no-load, the peak-to-peak ripple is about 34mV.

![12v input 24v output no-load.jpg]
12V 2A output, I forgot how much input, the ripple peak-to-peak value is about 25mV

![IMG_20230707_015104.jpg]
## Schematic

![SCH_Schematic1_1-P1_2023-07-08.png]
## PCB Top layer of the image

:

![2023-07-08_23-01-08.png]
Bottom layer:

![image4fce02ccf12b5d9a.png]
## Other open source project recommendations

- STM32F030C8T6 minimum system board and running lights (schematic diagram and PCB): [https:/ /blog.zeruns.tech/archives/715.html](https://blog.zeruns.tech/archives/715.html)
- I drew a minimal system board for MSP430F149 and made it open source: [https://blog.zeruns.tech/archives/713.html](https://blog.zeruns.tech/archives/713.html)
- 2007 Power Supply: 30 to 36V adjustable boost DCDC module (UC3843): [https://oshwhub.com/zeruns/36v-sheng-ya-dcdc-mo-kuai-uc3842](https://oshwhub.com /zeruns/36v-sheng-ya-dcdc-mo-kuai-uc3842)
- STC12C5A60S2 minimum system board/51 single-chip temperature display and temperature control fan: [https://blog.zeruns.tech/archives/721.html]( https://blog.zeruns.tech/archives/721.html)
- STM32F407 standard library project template with U8g2 graphics library ported: [https://blog.zeruns.tech/archives/722.html](https://blog.zeruns.tech/archives/722.html)
- Qinheng CH32V307VCT6 minimum system board open source: [https://blog.zeruns.tech/archives/726.html](https://blog.zeruns.tech/archives/726.html)