Features and Benefits
- High Efficiency: Up to 96%
- Low Ripple (35mVP-P) Burst Mode Operation; IQ = 40μA
- 1.5MHz Constant Frequency Operation
- No Schottky Diodes Required
- Low RDS(ON) Internal Switches: 0.35Ω
- Current Mode Operation for Excellent Line and Load Transient Response
- Short-Circuit Protected
- Low Dropout Operation: 100% Duty Cycle
- Ultralow Shutdown Current: IQ < 1µA
- Output Voltages from 5V down to 0.6V
- Power-On Reset Output
- Externally Synchronizable Oscillator
- Optional External Soft-Start
- Small Thermally Enhanced MSOP and 3mm × 3mm DFN Packages
The LTC3407A is a dual, constant frequency, synchronous step-down DC/DC converter. Intended for low power applications, it operates from a 2.5V to 5.5V input voltage range and has a constant 1.5MHz switching frequency, enabling the use of tiny, low cost capacitors and inductors 1mm or less in height. Each output voltage is adjustable from 0.6V to 5V. Internal synchronous 0.35Ω, 1A power switches provide high efficiency without the need for external Schottky diodes.
A user selectable mode input is provided to allow the user to trade-off ripple noise for low power efficiency. Burst Mode® operation provides the highest efficiency at light loads, while Pulse Skip Mode provides the lowest ripple noise at light loads.
To further maximize battery life, the P-channel MOSFETs are turned on continuously in dropout (100% duty cycle), and both channels draw a total quiescent current of only 40µA. In shutdown, the device draws <1µA.
|LTC3407-3||2x 800mA||2.5MHz||Fixed 1.8V/3.3V|
|LTC3407-4||2x 800mA||2.25MHz||Reduced POR Delay|
|LTC3407A||2x 600mA||1.5MHz||Low Ripple Burst Mode|
|LTC3407A-2||2x 800mA||2.25MHz||Low Ripple Burst Mode|
- PDAs/Palmtop PCs
- Digital Cameras
- Cellular Phones
- Wireless and DSL Modems
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)
Demonstration circuit DC1180 is a dual output regulator consisting of two identical constant frequency step-down converters, based on the LTC3407A monolithic dual synchronous buck regulator in the 3 × 3 DFN-10 package. The LTC3407A is similar to the LTC3407 but has a lower ripple Burst Mode operation and includes an optional external soft-start. The DC1180 has an input voltage range of 2.5V to 5.5V, and either output is capable of delivering up to 600mA of output current. In Burst Mode® operation, the DC supply current is typically only 25 µA (per channel) at no load, and less than 1 µA in shutdown. The DC1180 is a very efficient circuit: up to 96% for either circuit.
Tools & Simulations
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:
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
Design tools for the following parts are available in LTpowerCAD:
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.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.