利用MAX15026構(gòu)建LCD TV或機(jī)頂盒輔助電源的參考設(shè)計
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利用MAX15026構(gòu)建LCD TV或機(jī)頂盒輔助電源的參考設(shè)計
本文引用地址：http://www.104case.com/article/180124.htm摘要：本應(yīng)用筆記介紹了使用低成本、高效率同步降壓轉(zhuǎn)換器MAX15026構(gòu)建LCD TV或機(jī)頂盒輔助電源的參考設(shè)計。參考設(shè)計從6.5V至24V輸入電壓范圍，產(chǎn)生一個5V、5A輸出。
以下內(nèi)容列出了參考設(shè)計的主要規(guī)格、詳細(xì)電路示意圖(圖1)和所需的材料清單(表1)。
規(guī)格
- 輸入電壓范圍：6.5V至24V
- 輸出電壓：5V
- 輸出電流：5A
- 輸出電壓紋波(峰峰值)：50mV
- 轉(zhuǎn)換器開關(guān)頻率：300kHz
- 過流保護(hù)限制：6A
- 效率：> 90% (標(biāo)準(zhǔn)工作模式)
圖1. 同步整流降壓轉(zhuǎn)換器MAX15026在300kHz開關(guān)頻率下的電路圖
表1. 材料清單
| Designator | Value | Description | Part | Footprint | Manufacturer | Quantity |
| C1 | 220µF, 35V | Capacitor | EEVFK1V221P | 8mm x 10.2mm | Panasonic | 1 |
| C2, C3 | 4.7µF, 50V | Capacitor | GRM31CR71H475KA12L | 1206 | Murata | 2 |
| C4 | 0.1µF, 50V | Capacitor | GRM188R71H104KA93D | 0603 | Murata | 1 |
| C5 | 4.7µF, 6.3V | Capacitor | GRM188R60J475KE19D | 0603 | Murata | 1 |
| C6 | 2.2µF, 6.3V | Capacitor | GRM188R60J225KE19D | 0603 | Murata | 1 |
| C7 | 1µF, 50V | Capacitor | GRM21BR71H105KA12L | 0805 | Murata | 1 |
| C8 | 0.47µF, 16V | Capacitor | GRM188R71C474KA88D | 0603 | Murata | 1 |
| C9, C16 | 1200pF, 50V | Capacitor | GRM1885C1H122JA01D | 0603 | Murata | 2 |
| C10, C11 | 47µF, 10V | Capacitor | GRM32ER71A476KE15L | 1210 | Murata | 2 |
| C12, C13, C14 | 22µF, 10V | Capacitor | GRM31CR71A226KE15L | 1206 | Murata | 3 |
| C15 | 560pF, 50V | Capacitor | GRM1885C1H561JA01D | 0603 | Murata | 1 |
| C17 | 22pF, 50V | Capacitor | GRM1885C1H220JA01D | 0603 | Murata | 1 |
| R1 | 10Ω | Resistor | SMD 1% Resistor | 0603 | Vishay | 1 |
| R2 | 10kΩ | Resistor | SMD 1% Resistor | 0603 | Vishay | 1 |
| R3, R6 | 2.2Ω | Resistor | SMD 1% Resistor | 0603 | Vishay | 2 |
| R4 | 15kΩ | Resistor | SMD 1% Resistor | 0603 | Vishay | 1 |
| R5 | 56.2kΩ | Resistor | SMD 1% Resistor | 0603 | Vishay | 1 |
| R7 | 3.57Ω | Resistor | SMD 1% Resistor | 1206 | Vishay | 1 |
| R8 | 102kΩ | Resistor | SMD 1% Resistor | 0603 | Vishay | 1 |
| R9 | 13.7kΩ | Resistor | SMD 1% Resistor | 0603 | Vishay | 1 |
| R10 | 2.74kΩ | Resistor | SMD 1% Resistor | 0603 | Vishay | 1 |
| R11 | 47.5kΩ | Resistor | SMD 1% Resistor | 0603 | Vishay | 1 |
| L1 | 10µH ±20%, 5.5A | Inductor | SLF12575T-100M5R4-PF | 12.5mm x 12.5mm x 7.5mm | TDK | 1 |
| N1 | 30V, 6.3A, 35.5mΩ—Q1; 30V, 8.6A, 16.5mΩ—Q2 | Dual MOSFET | FDS6982AS | 8-SO | Fairchild | 1 |
| U1 | PWM Controller | Low-Cost, DC-DC Synchronous Buck Controller with a 4.5V to 28V Operating Range | MAX15026BETD+ | 14-TDFN-EP | Maxim | 1 |
性能數(shù)據(jù)
圖2. VIN = 24V、VOUT = 5V條件下的穩(wěn)壓輸出、輸入電壓和開關(guān)節(jié)點(diǎn)電壓。
Ch1：VOUT；Ch2：VIN；Ch3：LX節(jié)點(diǎn)電壓
圖3. 使能、軟啟動、軟停止和PGOOD時序波形。
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