Power Management
Switching Regulator
Step-Down (Buck) Regulators
Multiple Output Buck
Power Management
Switching Regulator
Step-Down (Buck) Regulators
Internal Power Switch Buck
Power Management
Supercapacitor Chargers
LTC3619B - 400mA/800mA Synchronous Step-Down DC/DC with Average Input Current Limit
Features
- Programmable Average Input Current Limit: ±5% Accuracy
- Dual Step-Down Outputs: Up to 96% Efficiency
- Low Noise Pulse-Skipping Operation at Light Loads
- Input Voltage Range: 2.5V to 5.5V
- Output Voltage Range: 0.6V to 5V
- 2.25MHz Constant-Frequency Operation
- Power Good Output Voltage Monitor for Each Channel
- Low Dropout Operation: 100% Duty Cycle
- Independent Internal Soft-Start for Each Channel
- Current Mode Operation for Excellent Line and Load Transient Response
- ±2% Output Voltage Accuracy
- Short-Circuit Protected
- Shutdown Current ≤ 1μA
- Available in Small Thermally Enhanced 10-Lead MS and 3mm × 3mm DFN Packages
Typical Application
Description
The LTC3619B is a dual monolithic synchronous buck regulator using a constant frequency current mode architecture.
The input supply voltage range is 2.5V to 5.5V, making it ideal for Li-Ion and USB powered applications. 100% duty cycle capability provides low dropout operation, extending the run time in battery-operated systems. Low output voltages are supported with the 0.6V feedback reference voltage. Channel 1 and channel 2 can supply 400mA and 800mA output current, respectively.
The LTC3619B’s programmable average input current limit is ideal for USB applications and for point-of-load power supplies because the LTC3619B’s limited input current will still allow its output to deliver high peak load currents without collapsing the input supply. When the sum of both channels’ currents exceeds the input current limit, channel 2 is current limited while channel 1 remains regulated. The operating frequency is internally set at 2.25MHz allowing the use of small surface mount inductors. Internal soft-start reduces in-rush current during start-up. The LTC3619B is available in small MSOP and 3mm × 3mm DFN packages. The LTC3619B is also available in a low quiescent current, high efficiency Burst Mode® version, LTC3619.
Packaging
For complete and up to date package information and drawings, please refer to our packaging page
MS-10, DFN-10
Order Info
- Part numbers ending in PBF are lead free. Please contact LTC marketing for information on lead based finish parts.
- 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 | Pins | Temp | Price (1-99) | Price (1k)* | RoHS Data |
|---|---|---|---|---|---|---|
| LTC3619BEDD#PBF | DFN | 10 | E | $3.22 | $2.25 | View |
| LTC3619BEDD#TRPBF | DFN | 10 | E | $2.31 | View | |
| LTC3619BEMSE#PBF | MSOP | 10 | E | $3.22 | $2.25 | View |
| LTC3619BEMSE#TRPBF | MSOP | 10 | E | $2.31 | View | |
| LTC3619BIDD#PBF | DFN | 10 | I | $3.79 | $2.65 | View |
| LTC3619BIDD#TRPBF | DFN | 10 | I | $2.71 | View | |
| LTC3619BIMSE#PBF | MSOP | 10 | I | $3.79 | $2.65 | View |
| LTC3619BIMSE#TRPBF | MSOP | 10 | I | $2.71 | View | |
| LTC3619EDD#PBF | DFN | 10 | E | $3.22 | $2.25 | View |
| LTC3619EDD#TRPBF | DFN | 10 | E | $2.31 | View | |
| LTC3619EMSE#PBF | MSOP | 10 | E | $3.22 | $2.25 | View |
| LTC3619EMSE#TRPBF | MSOP | 10 | E | $2.31 | View | |
| LTC3619IDD#PBF | DFN | 10 | I | $3.79 | $2.65 | View |
| LTC3619IDD#TRPBF | DFN | 10 | I | $2.71 | View | |
| LTC3619IMSE#PBF | MSOP | 10 | I | $3.79 | $2.65 | View |
| LTC3619IMSE#TRPBF | MSOP | 10 | I | $2.71 | View | |
| Buy Now • Request Samples | ||||||
Demo Boards
Linear Technology demo boards are offered free of charge to qualified customers. Contact your local sales office or distributor to request 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 |
|---|---|---|---|
| DC1489A-B | LTC3619BEDD Demo board | 400mA/800mA Synchronous Step-Down DC/DC with Average Input Current Limit | Contact Factory | |
| Buy Now | |||
Applications
- High Peak Load Current Applications
- USB Powered Devices
- Supercapacitor Charging
- Radio Transmitters and Other Handheld Devices
Simulate
LTspice IV is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. To download LTspice IV and other FREE simulation tools, please visit our Design Simulation page.
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 IV
- Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
- Step 3: If LTspice IV 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.
Related models available in LTspice IV
LTC3619
LTC3619B
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.
