LT3991IMSE#PBF

LT3991 is an adjustable frequency monolithic buck switching regulator that accepts a wide input voltage range 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 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 0.44ohm switch is included on 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. Applications include automotive battery regulation, power for portable products and industrial supplies.

• Feedback voltage of 1.19V
• Low ripple Burst Mode® operation, output ripple of <lt/> 15mVP-P
• Wide input voltage range from 4.3V to 55V, maximum output current of 1.2A
• Adjustable switching frequency from 200KHz to 2MHz, synchronizable between 250KHz to 2MHz
• Fast transient response, accurate 1V enable pin threshold
• Low shutdown current IQ of 700nA, power good flag
• Soft-start capability, internal compensation, saturating switch design: 0.44ohm on-resistance
• 10-lead plastic MSOP package, –40°C to 125°C operating temperature

Notes

ADI products are only authorized (and sold) for use by the customer and are not to be resold or otherwise passed on to any third party