LT3971AIMSE#PBF

Overview

The LT3971AIMSE#PBF is a monolithic buck switching regulator from Analog Devices, housed in a 10-lead MSOP package with an exposed thermal pad. It accepts an input voltage range of 4.3V to 38V and delivers up to 1.2A output current. The device features an adjustable switching frequency up to 2MHz and ultra-low quiescent current of 2.8μA during regulation. It includes an internal 0.33Ω power switch, soft-start capability via the SS pin, and a Power Good flag indicating when VOUT reaches 91% of the programmed level.

Feature Summary

• Ultra-low quiescent current design maintains high efficiency at light loads while keeping output ripple below 15mV in typical applications.
• Internally compensated current mode topology ensures fast transient response and stable loop performance across operating conditions.
• Accurate 1V threshold enable pin allows precise shutdown control, reducing input supply current to 700nA when disabled.

Applications

• USB-powered portable devices requiring low standby current
• Battery-operated equipment needing extended runtime
• Industrial systems with wide input voltage variations

Procurement Notes

Verify the suffix #PBF indicates lead-free RoHS compliance. Confirm the 'I' grade specifies industrial temperature range operation from -40°C to +125°C. Ensure the MSOP-10 package matches your PCB footprint requirements. Check for any specific ordering restrictions or environmental certifications required by your procurement policy.

Selection Notes

Select this component for applications demanding low static current and wide input voltage tolerance. The adjustable frequency feature allows optimization for size versus efficiency trade-offs. Consider the exposed pad for thermal management in high-current scenarios. Verify that the 1.2A output current meets the maximum load requirements of the target circuit.

Part Context

This part belongs to the LT3971 family of step-down regulators. The LT3971A variant offers improved reference accuracy compared to earlier versions. The MSOP package provides a compact solution for space-constrained designs. The series supports various fixed and adjustable output configurations.

Replacement Considerations

LT3971IMSE#PBF (Commercial grade version)

FAQ

What is the function of the SS pin?

The SS pin connects a capacitor to provide controlled inrush current and soft-start functionality, preventing excessive input current during startup.

How does the device handle low output currents?

It uses Burst Mode operation to maintain high efficiency at low output currents while keeping output ripple below 15mV in typical applications.