LM5141 Synchronous Buck Controllers

By Texas Instruments 39

LM5141 Synchronous Buck Controllers

Texas Instruments' LM5141 is a synchronous buck controller, intended for high voltage, wide VIN, step-down converter applications. The control method is peak current mode control. Current mode control provides inherent line feed-forward, cycle-by-cycle current limiting, and ease of loop compensation. The LM5141 features slew rate control to simplify the compliance with EMI requirements.

The LM5141 has two selectable switching frequencies: 2.2 MHz and 440 kHz. Gate drivers with slew rate control can be adjusted to reduce EMI.

In light or no-load conditions, the LM5141 operates in skip cycle mode for improved low power efficiency. The LM5141 has a high voltage bias regulator with automatic switch-over to an external bias to reduce the IQ current from VIN. Additional features include frequency synchronization, cycle-by-cycle current limit, hiccup mode fault protection for sustained overload, and power good output.

Features
  • -40ºC to +125ºC ambient operating temperature range
  • An AEC-Q100 qualified device is available
  • VIN 3.8 V to 65 V (70 V absolute maximum)
  • Output: fixed 3.3 V, 5 V, or adjustable from 1.5 V - 15 V with ±0.8% accuracy
  • Fixed 2.2 MHz or 440 kHz switching frequency with ±5% accuracy
  • High-side and low-side gate drive with slew rate control
  • Optional frequency shift by varying an analog voltage or RT resistor
  • Optional synchronization to an external clock
  • Optional spread spectrum
  • Shutdown mode IQ: 10 µA typical
  • Low standby mode IQ: 35 µA typical
  • 75 mV current limit threshold with ±0.9% accuracy
  • External resistor or DCR current sensing
  • Output enable logic input
  • Hiccup mode for sustained overload
  • Power good indication output
  • Selectable diode emulation or forced pulse width modulation
  • QFN-24 package with wettable flanks
Applications
  • Medical equipment
  • Industrial programmable logic controllers
  • Industrial PCs
  • Embedded PCs

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