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The LM2745/8 are high-speed synchronous buck regulator controllers with an accurate feedback voltage accuracy of ±1.5%. It can provide simple down conversion to output voltages as low as 0.6V. Though the control sections of the IC are rated for 3 to 6V, the driver sections are designed to accept input supply rails as high as 14V. The use of adaptive non-overlapping MOSFET gate drivers helps avoid potential shoot-through problems while maintaining high efficiency. The IC is designed for the more cost-effective option of driving only N-channel MOSFETs in both the high-side and low-side positions. It senses the low-side switch voltage drop for providing a simple, adjustable current limit.
The LM2745/8 features a fixed-frequency voltage-mode PWM control architecture which is adjustable from 50 kHz to 1 MHz with one external resistor. In addition, the LM2745 also allows the switching frequency to be synchronized to an external clock signal over the range of 250 kHz to 1 MHz. This wide range of switching frequency gives the power supply designer the flexibility to make better tradeoffs between component size, cost and efficiency.
Features include the ability to startup with a pre-biased load on the output, soft-start, input undervoltage lockout (UVLO) and Power Good (based on both undervoltage and overvoltage detection). In addition, the shutdown pin of the IC can be used for providing startup delay, and the soft-start pin can be used for implementing precise tracking, for the purpose of sequencing with respect to an external rail.
| Type | Title | Date | ||
|---|---|---|---|---|
| * | Data sheet | LM2745/48 Synch Buck Controller w/ Pre-Bias Startup & Optional Clk Synch datasheet (Rev. E) | 03 Apr 2013 | |
| User guide | LM2745 & LM2748 Buck Controller Evaluation Module User's Guide (Rev. B) | PDF | HTML | 09 Feb 2022 | |
| User guide | LM2745 Buck Controller Evaluation Module User's Guide (Rev. B) | PDF | HTML | 07 Feb 2022 | |
| 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 | ||
| Application note | AN-1603 LM274X Reference Designs (Rev. C) | 01 May 2013 | ||
| Application note | Current Limit Foldback Improves Short Circuit Protection in LM274X Family (Rev. B) | 23 Apr 2013 | ||
| Application note | Optmiz Pwr Cntrlr Dsigns thru Utiliz Freq & Sync, Ext Ref, Trking & Precis EN | 24 Apr 2008 |
For additional terms or required resources, click any title below to view the detail page where available.
| Package | Pins | Download |
|---|---|---|
| TSSOP (PW) | 14 | View options |
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