Features and Benefits
- Three Independent Current Mode Buck DC/DC Regulators (1.2A and 2 × 600mA)
- Single Pin Programmable VFB Servo Voltages from 800mV Down to 425mV (in 25mV Steps)
- Pull VFB High to Make Each 600mA Buck a Slave for Higher Current Operation
- Pulse-Skipping or Burst Mode® Operation
- Programmable Switching Frequency (1MHz to 3MHz) or Fixed 2.25MHz
- Synchronizable (1.2MHz to 3MHz)
- VIN Range 2.5V to 5.5V
- All Regulators Internally Compensated
- PGOOD Output Flag
- Quiescent Current <100μA (All Regulators in Burst Mode Operation)
- Zero Shutdown Current
- Overtemperature and Short-Circuit Protection
- Tiny 3mm × 3mm, 3mm × 4mm 20-Lead QFN and Thermally Enhanced TSSOP FE-16 Packages
The LTC3569 contains three monolithic, synchronous step-down DC/DC converters. Intended for medium power applications, it operates over a 2.5V to 5.5V input voltage range. The operating frequency is adjustable from 1MHz to 3MHz, allowing the use of tiny, low cost capacitors and inductors. The three output voltages are independently programmable by toggling the EN pins up to 15 times, lowering the 800mV FB references by 25mV per cycle. The first buck regulator sources load currents up to 1200mA. The other two buck regulators each provide 600mA.
The two 600mA buck regulators can also be configured to operate as slave power stages, running in parallel with another internal buck regulator to supply higher load currents. When operating as parallel, slave output stages, discrete external components are shared and available output currents sum together.
- Portable Applications with Multiple Supply Rails
- General Purpose Step-Down DC/DC
- Dynamic Voltage Scaling Applications
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 1340 is a triple output regulator consisting of three constant-frequency step-down converters integrated into LTC3569. DC1340 has an input voltage range of 2.5V to 5.5V, with regulators capable of delivering 1.2A or 600mA of load current on corresponding output. The three regulators operate independently with individual Enable pins and enter pulse skipping or burst mode at low loads for increasing efficiency. The DC1340 is a very efficient circuit with efficiency reading above 90%. High operating frequency of 2.25MHz allows exclusive use of the small size, low profile surface mount components. These features plus internal compensation circuits and extremely low quiescent current make the DC1340 demo board an ideal circuit for use in battery-powered, hand-held applications.
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.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, 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.
Models for the following parts are available in LTspice:
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.