LM5149
80-V synchronous buck DC/DC controller with ultra-low IQ and integrated active EMI filter
LM5149
- Functional Safety-Capable
- Two integrated EMI mitigation mechanisms
- Active EMI Filter for enhanced EMI performance at lower frequencies
- Selectable dual random spread spectrum (DRSS) for enhanced EMI performance across low and high-frequency bands
- EMI reduced by an average of 25 dBµV
- Reduces the external differential-mode input filter size by 50% and lowers systems cost
- Optimized for CISPR 32 Class B requirements
- Versatile synchronous buck DC/DC controller
- Wide input voltage range of 3.5 V to 80 V
- 1% accurate, fixed 3.3 V, 5 V, 12 V, or adjustable output from 0.8 V to 55 V
- 150°C maximum junction temperature
- Shutdown mode current: 2.3 µA
- No-load sleep current: 9.5 µA
- Stackable up to two phases
- Advanced dropout with frequency foldback
- Switching frequency from 100 kHz to 2.2 MHz
- SYNC in and SYNC out capability
- Inherent protection features for robust design
- Internal hiccup-mode overcurrent protection
- ENABLE and PGOOD functions
- VCC, VDDA, and gate-drive UVLO protection
- Internal or external loop compensation
- Thermal shutdown protection with hysteresis
- Create a custom design using the LM5149 with WEBENCH Power Designer
The LM5149 is a 80-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 LM5149 can be set up in interleaved dual-phase mode with accurate current sharing for high-current applications. The device can operate with VIN as low as 3.5 V, at nearly 100% duty cycle if needed.
The LM5149 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 LM5149 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 LM5149- 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.
Technical documentation
Type | Title | Date | ||
---|---|---|---|---|
* | Data sheet | LM5149 80-V, Synchronous, Buck, DC/DC Controller with Ultra-Low IQ and Integrated Active EMI Filter datasheet (Rev. A) | PDF | HTML | 24 Jan 2023 |
Application note | How to Implement a Simple Constant Current Regulation Scheme to a PCM Based Buck | PDF | HTML | 16 Aug 2023 | |
Functional safety information | LM5149 Functional Safety, FIT Rate, Failure Mode Distribution and Pin FMA | PDF | HTML | 16 Dec 2022 | |
User guide | LM25149-Q1 EVM User's Guide (Rev. A) | PDF | HTML | 29 Apr 2022 |
Design & development
For additional terms or required resources, click any title below to view the detail page where available.
LM25149-Q1EVM-2100 — LM25149-Q1 5.5-V to 36-V, low IQ, synchronous buck DC/DC controller evaluation module
LM5149-Q1EVM-400 — LM5149-Q1 evaluation module, 72-V, low-IQ, synchronous buck DC/DC controller with active EMI filter
The LM5149-Q1EVM-400 high-density evaluation module (EVM) is designed to showcase the performance of the LM5149-Q1 high-performance, automotive, synchronous buck DC/DC buck controller. The EVM operates over a wide input voltage range of 15 V to 72 V to deliver a fixed 12-V output with better than (...)
Package | Pins | CAD symbols, footprints & 3D models |
---|---|---|
VQFN (RGY) | 24 | Ultra Librarian |
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