Texas Instruments LM25149/LM25149-Q1 Buck DC/DC Controller
Texas Instruments LM25149/LM25149-Q1 Synchronous Buck DC/DC Controller is a 42V, 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/LM25149-Q1 can be set up in interleaved mode with accurate current sharing for high-current applications. It can operate with VIN as low as 3.5V, at nearly 100% duty cycle if needed.
The LM25149/LM25149-Q1 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 industry-standard EMC tests' multiple resolution bandwidth (RBW) settings.
Additional features of the LM25149/LM25149-Q1 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. It also has precision enable input, monotonic start-up into a pre-biased load, integrated VCC bias supply regulator and bootstrap diode, internal 3ms soft-start time, and thermal shutdown protection with automatic recovery.
The Texas Instruments LM25149/LM25149-Q1 controller comes in a 3.5mm × 5.5mm thermally enhanced, 24-pin VQFN package with an exposed pad to aid thermal dissipation. The LM25149-Q1 devices are AEC-Q100 qualified for automotive applications.
Features
- Functional Safety-Capable
- Documentation available to aid functional safety system design
- 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 25dBµV
- 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 3.5V to 42V
- 1% accurate, fixed 3.3V, 5V, 12V, or adjustable output from 0.8V to 36V
- 150°C maximum junction temperature
- Shutdown mode current: 2.3µA
- No-load sleep current: 9.5µA
- Stackable up to two phases
- Advanced dropout with frequency foldback
- Switching frequency from 100kHz to 2.2MHz
- 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
Applications
- Building automation
- Industrial transport
- Power delivery
- Test and measurement
- Aerospace and defense
Datasheets
Typical Application Schematic
Related Development Tool
Texas Instruments LM25149-Q1EVM-2100 Controller Evaluation Module
Showcases the LM25149-Q1 high-performance, automotive synchronous buck DC/DC buck controller.