LTC3520 - Synchronous 1A Buck-Boost and 600mA Buck Converters
Features
- Dual High Efficiency DC/DC Converters:
Buck-Boost (VOUT: 2.2V to 5.25V, IOUT = 1A at
VOUT = 3.3V, VIN ≥ 3V)
Buck (VOUT: 0.8V to VIN, IOUT = 600mA) - 2.2V to 5.5V Input Voltage Range
- Pin-Selectable Burst Mode® Operation
- Uncommitted Gain Block for LDO Controller, Battery Good Indication or Sequencing
- Programmable 100kHz to 2MHz Switching Frequency
- 55μA Total Quiescent Current for Both Converters in Burst Mode Operation
- Thermal and Overcurrent Protection
- <1μA Quiescent Current in Shutdown
- 24-Lead 4mm × 4mm QFN Package
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC3520 combines 1A buck-boost and 600mA synchronous buck DC/DC converters in a tiny 4mm x 4mm package. A programmable switching frequency allows the efficiency to be optimized while minimizing the solution footprint. Both converters feature soft-start and current limit protection. The uncommitted gain block can be configured as an LDO or utilized as a battery-good comparator.The buck converter is current mode controlled with internal synchronous rectification to improve efficiency. Pin-select- able Burst Mode operation can be enabled to improve light load efficiency, or the buck converter can be operated in low noise PWM mode for sensitive applications.
The buck-boost converter provides continuous conduction operation to maximize efficiency and minimize noise. At light loads, use of Burst Mode operation will improve efficiency.
The LTC3520 provides a <1µA shutdown mode and over- temperature shutdown on both converters. The LTC3520 is available in a low profile (0.75mm) 24-lead 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 |
|---|---|---|---|---|---|
| LTC3520EUF#PBF | 4x4 QFN-24 | UF | E | 05-08-1697 | Yes |
| LTC3520EUF#TRPBF | 4x4 QFN-24 | UF | E | 05-08-1697 | Yes |
| LTC3520IUF#PBF | 4x4 QFN-24 | UF | I | 05-08-1697 | Yes |
| LTC3520IUF#TRPBF | 4x4 QFN-24 | UF | I | 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 | |
|---|---|---|---|---|---|---|
| LTC3520EUF#PBF | 4x4 QFN-24 | E | $5.00 | $3.50 | Yes | |
| LTC3520EUF#TRPBF | 4x4 QFN-24 | E | $3.56 | Yes | ||
| LTC3520IUF#PBF | 4x4 QFN-24 | I | $5.76 | $4.03 | Yes | |
| LTC3520IUF#TRPBF | 4x4 QFN-24 | I | $4.09 | 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 |
|---|---|---|---|
| DC1062A | LTC3520EUF| Buck-Boost w/ 400mA Buck, Vin = 2.2V to 5.5V, Vout1 = 3.3V @ 1A (BB), Vout2 = 1.8V @ 0.6A, Vout3 (LDO Post Regulator) = 1.5V @ 200mA | $125.00 | |
| Buy Now | |||
Designed for Automotive and Transportation Applications
AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC3520IUF#PBF | 4x4 QFN-24 | I | $5.76 | $4.03 | Yes | |
| LTC3520IUF#TRPBF | 4x4 QFN-24 | I | $4.09 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- Portable Media Players
- Digital Cameras
- Handheld PCs, PDAs
- GPS Receivers
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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:
LTC3520
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.
