DC-DC Switching Buck (Step Down) Regulator, Adjustable, 4.3V-55Vin, 1.19V-30Vout, 1.2Aout, MSOP-10

LT3991EMSE#PBF - DC-DC Switching Buck (Step Down) Regulator, Adjustable, 4.3V-55Vin, 1.19V-30Vout, 1.2Aout, MSOP-10

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Product Overview

The LT3991EMSE#PBF is a 1.2A monolithic step-down Switching Regulator accepts two input voltages up to 55V. Low quiescent current design consumes only 2.8µA of supply current while regulating with no load. Low ripple Burst Mode® operation maintains high efficiency at low output currents while keeping the output ripple below 15mV in a typical application. An internally compensated current mode topology is used for fast transient response and good loop stability. A high efficiency 0.44R switch is included on the die along with a boost Schottky diode and the necessary oscillator, control and logic circuitry. An accurate 1V threshold enable pin can be used to shut down the LT3991, reducing the input supply current to 700nA. A capacitor on the SS pin provides a controlled inrush current (soft-start). A power good flag signals when VOUT reaches 91% of the programmed output voltage.
  • Ultralow quiescent current (2.8µA IQ regulating 12VIN to 3.3VOUT)
  • Fixed output voltages (3.3, 5V 2.1µA IQ Regulating 12VIN)
  • Low ripple Burst Mode® operation (output ripple <15mVP-P)
  • 200kHz to 2MHz Adjustable switching frequency
  • Synchronizable between 250kHz to 2MHz
  • Fast transient response
  • Accurate 1V enable pin threshold
  • Low shutdown current (IQ = 700nA)
  • Power good flag
  • Soft-start capability
  • Internal compensation
  • Saturating switch design (0.44R on-resistance)


Automotive, Portable Devices, Industrial, Power Management

Product Information

Buck (Step Down)
MSL 1 - Unlimited
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