Packaging information
| Package | Pins VQFN (RGY) | 24 |
| Operating temperature range (°C) -40 to 150 |
| Package qty | Carrier 3,000 | LARGE T&R |
Features for the LM25149
- 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 42 V
- 1% accurate, fixed 3.3-V, 5-V, 12-V, or adjustable output from 0.8 V to 36 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 LM25149 with WEBENCH Power Designer
Description for the LM25149
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.