Alternative Parts
Overview
Features and Benefits
- VIN and VOUT Limited Only by External Components
- Internal or Programmable External Soft-Start
- Constant Frequency 200kHz Operation
- Adjustable Current Limit
- Current Sense Resistor Optional
- ±1.5% Voltage Reference Accuracy
- Current Mode Operation for Excellent Line and Load Transient Response
- 4.1V Undervoltage Threshold for Logic Level
MOSFET Applications - Low Quiescent Current: 300µA
- Low Profile (1mm) ThinSOT™ and (0.75mm) 2mm × 3mm DFN Package
Product Details
The LTC3873-5 is a constant frequency current mode controller for boost, flyback or SEPIC DC/DC converters designed to drive an N-channel MOSFET for high input and output voltage converter applications.
The LTC3873-5 provides ±1.5% output voltage accuracy and consumes only 300μA quiescent current during normal operation and only 50μA during micropower start-up. Using a 9.3V internal shunt regulator, the LTC3873-5 can be powered from a high input voltage through a resistor or it can be powered directly from a low impedance DC voltage of 9V or less. Soft-start can be programmed using an external capacitor.
The LTC3873-5 is available in 8-lead ThinSOT and 2mm × 3mm DFN packages.
LTC3873 | LTC3873-5 | |
VCC UV+ | 8.4V | 3.9V |
VCC UV– | 4V | 2.9V |
Applications
- Telecom Power Supplies
- Automotive Power Supplies
- PoE Applications
Product Lifecycle
Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Documentation
Reliability Data (1)
Tools & Simulations
LTspice
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

Models for the following parts are available in LTspice:
Reference Materials
Design Resources
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Support & Discussions
LTC3873-5 Discussions
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.