LTC3619
400mA/800mA Synchronous Step-Down DC/DC with Average Input Current Limit
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Overview
Features and Benefits
- Programmable Average Input Current Limit: ±5% Accuracy
- Dual Step-Down Outputs: Up to 96% Efficiency
- Low Ripple (<25mVP-P) Burst Mode® Operation: IQ = 50μA
- 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 MSE and 3mm × 3mm DFN Packages
Product Details
The LTC3619 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 LTC3619’s programmable average input current limit is ideal for USB applications and for point-of-load power supplies because the LTC3619’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 LTC3619 is available in small MSOP and 3mm × 3mm DFN packages and is also available in a low noise, high efficiency pulse skipping version, LTC3619B.
| Light Load Operation | |
| LTC3619 | Low Ripple Burst Mode (< 20mVpp), Iq < 50uA |
| LTC3619B | Pulse Skip (<5mVpp) |
Applications
- High Peak Load Current Applications
- USB Powered Devices
- Supercapacitor Charging
- Radio Transmitters and Other Handheld Devices
Product Lifecycle
Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
Documentation & Resources
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R457 Reliability Data3/26/2018PDF65 K
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DC1489A - Demo Manual10/23/2009PDF778K
Tools & Simulations
LTspice
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.
Models for the following parts are available in LTspice:
LTC3619
LTC3619B
Design Resources
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.
PCN-PDN Information
Support & Discussions
Sample & Buy
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Lead Times
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Evaluation Boards
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.