LTC3545/LTC3545-1 - Triple 800mA Synchronous Step-Down Regulator - 2.25MHz
Features
- Three 800mA Outputs
- High Efficiency: Up to 95%
- 2.25V to 5.5V Input Voltage Range
- Low Ripple (<20mVP-P) Burst Mode Operation
IQ: 58uA - 2.25MHz Constant Frequency Operation
- Synchronizable to External 1MHz to 3MHz Clock
- Power Good Indicators Ease Supply Sequencing
- 0.6V Reference Allows Low Output Voltages
- Current Mode Operation/Excellent Transient Response
- Low Profile 16-Lead 3mm × 3mm QFN Package
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC3545/LTC3545-1 are triple, high efficiency, monolithic synchronous buck regulators using a constant frequency, current mode architecture. The regulators operate independently with separate run pins. The 2.25V to 5.5V input voltage range makes the LTC3545/LTC3545-1 well suited for single Li-Ion battery-powered applications. Low ripple pulse skip mode or high efficiency Burst Mode operation is externally selectable. PWM pulse skip mode operation provides very low output ripple voltage while Burst Mode operation increases efficiency at low output loads.Switching frequency is internally set to 2.25MHz, or the switching frequency can be synchronized to an external 1MHz to 3MHz clock. Power good indicators easily allow power on sequencing between the three regulators.
The internal synchronous switches increase efficiency and eliminate external Schottky diodes. Low output voltages are supported with the 0.6V feedback reference voltage.
The LTC3545-1 replaces the SYNC/MODE function with a third PGOOD pin and forces Burst Mode operation.
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 |
|---|---|---|---|---|---|
| LTC3545EUD-1#PBF | 3x3 QFN-16 | UD | E | 05-08-1700 | Yes |
| LTC3545EUD-1#TRPBF | 3x3 QFN-16 | UD | E | 05-08-1700 | Yes |
| LTC3545EUD#PBF | 3x3 QFN-16 | UD | E | 05-08-1700 | Yes |
| LTC3545EUD#TRPBF | 3x3 QFN-16 | UD | E | 05-08-1700 | Yes |
| LTC3545IUD-1#PBF | 3x3 QFN-16 | UD | I | 05-08-1700 | Yes |
| LTC3545IUD-1#TRPBF | 3x3 QFN-16 | UD | I | 05-08-1700 | Yes |
| LTC3545IUD#PBF | 3x3 QFN-16 | UD | I | 05-08-1700 | Yes |
| LTC3545IUD#TRPBF | 3x3 QFN-16 | UD | I | 05-08-1700 | 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 | |
|---|---|---|---|---|---|---|
| LTC3545EUD-1#PBF | 3x3 QFN-16 | E | $4.43 | $3.10 | Yes | |
| LTC3545EUD-1#TRPBF | 3x3 QFN-16 | E | $3.16 | Yes | ||
| LTC3545EUD#PBF | 3x3 QFN-16 | E | $4.43 | $3.10 | Yes | |
| LTC3545EUD#TRPBF | 3x3 QFN-16 | E | $3.16 | Yes | ||
| LTC3545IUD-1#PBF | 3x3 QFN-16 | I | $5.10 | $3.57 | Yes | |
| LTC3545IUD-1#TRPBF | 3x3 QFN-16 | I | $3.63 | Yes | ||
| LTC3545IUD#PBF | 3x3 QFN-16 | I | $5.10 | $3.57 | Yes | |
| LTC3545IUD#TRPBF | 3x3 QFN-16 | I | $3.63 | 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 |
|---|---|---|---|
| DC1193A-A | LTC3545EUD Demo Board | 2.25V to 5.5VIN, 1.2V@0.8A, 1.5V@0.8A, 1.8V@0.8A; SYNC Pin | $150.00 | |
| DC1193A-B | LTC3545EUD Demo Board | 2.25V to 5.5VIN, 1.2V@0.8A, 1.5V@0.8A, 1.8V@0.8A; PGOOD Pin, Burst Mode Only | $150.00 | |
| 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 | |
|---|---|---|---|---|---|---|
| LTC3545IUD-1#PBF | 3x3 QFN-16 | I | $5.10 | $3.57 | Yes | |
| LTC3545IUD-1#TRPBF | 3x3 QFN-16 | I | $3.63 | Yes | ||
| LTC3545IUD#PBF | 3x3 QFN-16 | I | $5.10 | $3.57 | Yes | |
| LTC3545IUD#TRPBF | 3x3 QFN-16 | I | $3.63 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- Smart Phones
- Wireless and DSL Modems
- Digital Still Cameras
- Portable Instruments
- Point of Load Regulation
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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
To launch a ready to run LTspice demonstration circuit for this part:
- Step 1: If you have not installed LTspice on this computer, download and install LTspice
- Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
- Step 3: If LTspice does not automatically open after clicking the link above, you can instead run the simulation by right clicking on the link and selecting "Save Target As." After saving the file to your computer, start LTspice and open the demonstration circuit by selecting 'Open' from the 'File' menu
To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.
Models for the following parts are available in LTspice:
LTC3545
LTC3545-1
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.
