The LM25117 is a synchronous buck controller intended for step-down regulator applications from a high voltage or widely varying input supply. The control method is based upon current mode control utilizing an emulated current ramp. Current mode control provides inherent line feed-forward, cycle-by-cycle current limiting and ease of loop compensation. The use of an emulated control ramp reduces noise sensitivity of the pulse-width modulation circuit, allowing reliable control of very small duty cycles necessary in high input voltage applications.
The operating frequency is programmable from 50 kHz to 750 kHz. The LM25117 drives external high-side and low-side NMOS power switches with adaptive dead-time control. A user-selectable diode emulation mode enables discontinuous mode operation for improved efficiency at light load conditions. A high voltage bias regulator that allows external bias supply further improves efficiency. The LM25117’s unique analog telemetry feature provides average output current information. Additional features include thermal shutdown, frequency synchronization, hiccup mode current limit and adjustable line undervoltage lockout.
| Type | Title | Date | ||
|---|---|---|---|---|
| * | Data sheet | LM25117/Q1 Wide Input Range Synchronous Buck Controller With Analog Current Monitor datasheet (Rev. F) | PDF | HTML | 27 Aug 2015 |
| White paper | Valuing wide VIN, low EMI synchronous buck circuits for cost-driven, demanding a (Rev. A) | 10 Apr 2019 | ||
| White paper | Overcoming Challenges in Designing Step-Dwn Reg Apps w/40V Input Voltage (Rev. A) | 03 Jul 2018 | ||
| Application note | How to Design a Simple Constant Current/Constant Voltage Buck Converter | 26 Jun 2018 | ||
| Selection guide | Power Management Guide 2018 (Rev. R) | 25 Jun 2018 | ||
| Analog Design Journal | Reduce buck-converter EMI and voltage stress by minimizing inductive parasitics | 21 Jul 2016 | ||
| Analog Design Journal | Analog Applications Journal 3Q 2015 | 24 Jul 2015 | ||
| Analog Design Journal | Ceramic or electrolytic output capacitors in DC/DC converters—Why not both? | 24 Jul 2015 | ||
| User guide | AN-2065 LM5119 Evaluation Board (Rev. B) | 24 Apr 2013 | ||
| User guide | AN-2103 LM5117 Evaluation Board (Rev. B) | 24 Apr 2013 |
For additional terms or required resources, click any title below to view the detail page where available.
The LM25117 evaluation board provides the design engineer with a fully functional synchronous buck converter based on Emulated Current Mode Control to evaluate the LM25117 controller IC. The evaluation board provides 3.3V output with a 9A current capability in addition with average output current (...)
| Package | Pins | CAD symbols, footprints & 3D models |
|---|---|---|
| HTSSOP (PWP) | 20 | Ultra Librarian |
| WQFN (RTW) | 24 | Ultra Librarian |
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