Features and Benefits
- Programmable Average Input Current Limit
- 5% Input Current Accuracy
- 200mA to 1000mA Program Range
- VIN: 1.8V to 5.5V, VOUT: 2V to 5.25V
- Supports High Current GSM/GPRS Load Burst
- VIN > VOUT Operation
- 1.6MHz Fixed Frequency Operation
- Internal Current Sense Resistor
- 1.2A Peak Current Limit
- Up to 93% Efficiency
- Output Disconnect in Shutdown
- Low Quiescent Current Burst Mode® Operation (15μA)
- Available in 2mm × 3mm × 0.75mm DFN Package
The LTC3125 is a high efficiency, synchronous step-up DC/DC converter with an accurate programmable average input current limit. The resistor programmable average input current limit is 5% accurate at 500mA and is suitable for a wide variety of applications. In mobile computing, GSM and GPRS cards demand high current pulses well beyond the capability of the PC Card and CompactFlash slots. The LTC3125 in concert with a reservoir capacitor, keeps the slot power safely within its capabilities providing a high performance and simple solution.
Synchronous rectification produces high efficiency while the 1.6MHz switching frequency minimizes the solution footprint. The current mode PWM design is internally compensated. Output disconnect allows the load to discharge in shutdown, while also providing inrush current limiting.
Other features include a <1μA shutdown current, short circuit and thermal overload protection. The LTC3125 is offered in a low profile 0.75mm × 2mm × 3mm package.
- GSM/GPRS PCMCIA/CompactFlash PC Card Modems
- Wireless Emergency Locators
- Portable Radios
- Supercap Chargers
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 1267A is a step-up DC/DC regulator featuring the LTC3125EDCB and is ideally suited for pulsed load applications where the input current needs to be limited. Demonstration circuit 1267A is configured for 500mA maximum input current limit and can handle pulsed load currents of up to 2A, with duty cycles of up to 15%. The input voltage range is 3.3V ±10%.
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.