LTC3121
RECOMMENDED FOR NEW DESIGNS15V, 1.5A Synchronous Step-Up DC/DC Converter with Output Disconnect
- Part Models
- 4
- 1ku List Price
- Starting From $3.56
Overview
- VIN Range: 1.8V to 5.5V, 500mV After Start-Up
- Output Voltage Range: 2.2V to 15V
- 400mA Output Current for VIN = 5V and VOUT = 12V
- Output Disconnects from Input When Shut Down
- Synchronous Rectification: Up to 95% Efficiency
- Inrush Current Limit
- Up to 3MHz Adjustable Switching Frequency Synchronizable to External Clock
- Selectable Burst Mode® Operation: 25μA IQ
- Output Overvoltage Protection
- Soft-Start
- <1μA IQ in Shutdown
- 12-Lead, 3mm × 4mm Thermally Enhanced DFN Package
The LTC3121 is a synchronous step-up DC/DC converter with true output disconnect and inrush current limiting. The 1.5A current limit along with the ability to program output voltages up to 15V makes the LTC3121 well suited for a variety of demanding applications. Once started, operation will continue with inputs down to 500mV, extending run time in many applications.
The LTC3121 features output disconnect in shutdown, dramatically reducing input power drain and enabling VOUT to completely discharge. Adjustable PWM switching from 100kHz to 3MHz optimizes applications for highest efficiency or smallest solution footprint. The oscillator can also be synchronized to an external clock for noise sensitive applications. Selectable Burst Mode operation reduces quiescent current to 25μA, ensuring high efficiency across the entire load range. An internal soft-start limits inrush current during start-up.
Other features include a <1μA shutdown current and robust protection under short-circuit, thermal overload, and output overvoltage conditions. The LTC3121 is offered in a low profile 12-lead (3mm × 4mm × 0.75mm) DFN package.
Applications
- PCI Express Cards/Systems
- Piezo Actuators
- Small DC Motors
- 12V Analog Rail From Battery, 5V, or Backup Capacitor
Documentation
Data Sheet 1
User Guide 1
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. View our quality and reliability program and certifications for more information.
| Part Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| LTC3121EDE#PBF | 12-Lead DFN (4mm x 3mm w/ EP) | ||
| LTC3121EDE#TRPBF | 12-Lead DFN (4mm x 3mm w/ EP) | ||
| LTC3121IDE#PBF | 12-Lead DFN (4mm x 3mm w/ EP) | ||
| LTC3121IDE#TRPBF | 12-Lead DFN (4mm x 3mm w/ EP) |
This is the most up-to-date revision of the Data Sheet.
Software Resources
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Tools & Simulations
LTspice 1
Models for the following parts are available in LTspice:
- LTC3121
LTpowerCAD 1
Design tools for the following parts are available in LTpowerCAD:
- LTC3121
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.
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.