The LM25149 is a 42-V, ultra-low IQ synchronous buck DC/DC controller for high-current, single-output applications. The controller uses a peak current-mode control architecture for easy loop compensation, fast transient response, and excellent load and line regulation. The LM25149 can be set up in interleaved dual-phase mode with accurate current sharing for high-current applications. It can operate with VIN as low as 3.5 V, at nearly 100% duty cycle if needed.
The LM25149 has two unique EMI reduction features: active EMI filter and dual random spread spectrum (DRSS). The active EMI filter senses any noise or ripple voltage on the DC input bus and injects an out-of-phase cancellation signal to reduce the disturbance. DRSS combines low-frequency triangular and high-frequency randomized modulations to mitigate EMI across lower and higher frequency bands, respectively. This hybrid technique aligns with the multiple resolution bandwidth (RBW) settings specified in industry-standard EMC tests.
Additional features of the LM25149 include 150°C maximum junction temperature operation, user-selectable diode emulation for lower current consumption at light-load conditions, open-drain power-good flag for fault reporting and output monitoring, precision enable input, monotonic start-up into prebiased load, integrated VCC bias supply regulator and bootstrap diode, internal 3-ms soft-start time, and thermal shutdown protection with automatic recovery.
The LM25149 controller comes in a 3.5-mm × 5.5-mm thermally enhanced, 24-pin VQFN package with an exposed pad to aid in thermal dissapation.
| 類型 | 標題 | 日期 | ||
|---|---|---|---|---|
| * | Data sheet | LM25149 42-V Synchronous Buck DC/DC Controller with Ultra-Low IQ and Integrated Active EMI Filter datasheet (Rev. B) | PDF | HTML | 2021年 12月 15日 |
| Application note | How to Implement a Simple Constant Current Regulation Scheme to a PCM Based Buck | PDF | HTML | 2023年 8月 16日 | |
| User guide | LM25149-Q1 EVM User's Guide (Rev. A) | PDF | HTML | 2022年 4月 29日 | |
| Functional safety information | LM25149 Functional Safety, FIT Rate, Failure Mode Distribution and Pin FMA | PDF | HTML | 2021年 12月 7日 | |
| E-book | An Engineer’s Guide to Low EMI in DC/DC Regulators | 2021年 4月 21日 | ||
| Technical article | How to reduce EMI and shrink power-supply size with an integrated active EMI filte | PDF | HTML | 2021年 4月 5日 |
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LM5149-Q1EVM-400 高密度評估模組 (EVM) 的設計目的在於展示 LM5149-Q1 高性能、車用同步降壓 DC/DC 降壓控制器。EVM 可在 15 V 至 72 V 的廣泛輸入電壓範圍內運作，可提供高於 1% 設定點準確度，及高達 8-A 輸出電流的固定 12-V 輸出。LM5149-Q1 提供先進的 EMI 性能、超低 IQ 保護功能，可在穩壓器故障狀況下提供防護，包括電壓過低鎖定、內部緩啟動、打嗝模式過電流保護，以及過熱自動關機。該設備還包括開漏 PGOOD 指示器和 SYNC IN 功能。
| 封裝 | 針腳 | CAD 符號、佔位空間與 3D 模型 |
|---|---|---|
| VQFN (RGY) | 24 | Ultra Librarian |