Features and Benefits
- Highest Efficiency Current Mode Controller
- No Sense Resistor Required
- Stable High Current Operation
- Dual N-Channel MOSFET Synchronous Drive
- Wide VIN Range: 3.7V to 36V
- Wide VOUT Range: 1.19V to VIN
- ±1% 1.19V Reference
- Programmable Fixed Frequency with Injection Lock
- Very Low Drop Out Operation: 99% Duty Cycle
- Forced Continuous Mode Control Pin
- Optional Programmable Soft Start
- Pin Selectable Output Voltage
- Foldback Current Limit
- Output Overvoltage Protection
- Logic Controlled Micropower Shutdown: IQ < 30µA
- Available in 16-Lead Narrow SSOP and SO Packages
The LTC1625 is a synchronous step-down switching regulator controller that drives external N-Channel power MOSFETs using few external components. Current mode control with MOSFET VDS sensing eliminates the need for a sense resistor and improves efficiency. The frequency of a nominal 150kHz internal oscillator can be synchronized to an external clock over a 1.5:1 frequency range.
Burst Mode™ operation at low load currents reduces switching losses and low dropout operation extends operating time in battery-powered systems. A forced continuous mode control pin can assist secondary winding regulation by disabling Burst Mode operation when the main output is lightly loaded.
Fault protection is provided by foldback current limiting and an output overvoltage comparator. An external capacitor attached to the RUN/SS pin provides soft start capability for supply sequencing. A wide supply range allows operation from 3.7V (3.9V for LTC1625I) to 36V at the input and 1.19V to VIN at the output.
- Notebook and Palmtop Computers, PDAs
- Cellular Telephones and Wireless Modems
- Battery Chargers
- Distributed Power
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 DC2008 is DC/DC buck converter featuring the LTC1625 constant frequency current mode buck controller. The DC2008A operates over a 4.5V to 28V input and provides 15A of output current as shown in Figure 3. The 225kHz constant frequency operation results in a small and efficient circuit. The converter provides high output voltage accuracy (typically ±3%) over a wide load range with no minimum load requirement. The demonstration circuit can be easily modified to generate different output voltages.
Tools & Simulations
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Technical Articles (3)
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
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