LTC3421 - 3A, 3MHz Micropower Synchronous Boost Converter with Output Disconnect
Features
- Synchronous Rectification: Up to 96% Efficiency
- True Output Disconnect
- Inrush Current Limiting
- Very Low Quiescent Current: 12µA
- Up to 1.5A Continuous Output Current
- Fixed Frequency Operation Up to 3MHz
- 0.5V to 4.5V Input Range
- 2.4V to 5.25V Adjustable Output Voltage
- Guaranteed 1V Start-Up
- Programmable Current Limit
- Programmable Soft-Start
- Synchronizable Oscillator
- Manual or Automatic Burst Mode® Operation
- Low-Battery Comparator
- <1µA Shutdown Current
- 1.22V Reference Output Voltage
- Small (4mm x 4mm) Thermally Enhanced QFN Package
Typical Application
Description
The LTC3421 is a high efficiency, current mode, fixed frequency, step-up DC/DC converter with true output disconnect and inrush current limiting. The device includes a 0.10 Ohm N-channel MOSFET switch and a 0.14 Ohm P-channel synchronous rectifier. This product has the ability to simply program the output voltage, switching frequency, current limit, soft-start, Burst Mode threshold and loop compensation with external passive components.
Quiescent current is only 12µA during Burst Mode operation, maximizing battery life in portable applications. The oscillator frequency can be programmed up to 3MHz and can be synchronized to an external clock applied to the SYNC pin. An open-drain uncommitted low-battery comparator is included. The part maintains operation in applications with a secondary cell powering the output voltage during shutdown.
Other features include: 1µA shutdown, antiringing control, thermal limit and reference output.
The LTC3421 is available in a small 4mm x 4mm QFN package.
Packaging
CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.
For complete and up to date package information and drawings, please refer to our packaging page
| Part Number | Package | Code | Temp | Package Drawing |
RoHS |
|---|---|---|---|---|---|
| LTC3421EUF#PBF | 4x4 QFN-24 | UF | E | 05-08-1697 | Yes |
| LTC3421EUF#TRPBF | 4x4 QFN-24 | UF | E | 05-08-1697 | Yes |
Order Info
- Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
- Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
- Please refer to our general ordering information or the product datasheet for more details
Package Variations and Pricing
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC3421EUF#PBF | 4x4 QFN-24 | E | $5.00 | $3.50 | Yes | |
| LTC3421EUF#TRPBF | 4x4 QFN-24 | E | $3.60 | Yes | ||
| Buy Now • Request Samples | ||||||
Demo Boards
Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC565A | LTC3421EUF | Vin = 1.8V to 3.2V, Vout = 3.3V @ 1A | $125.00 | |
| Buy Now | |||
Applications
- Handheld Computers
- Cordless Phones
- GPS Receivers
- Battery Backup Supplies
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Design Tools
LTspice
LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice
Models for the following parts are available in LTspice:
LTC3421
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.
