Features and Benefits
- Wide VIN Range: 3V to 30V Operation with Line Feedforward Compensation
- Leading Edge Modulation Architecture for Extremely Low Duty Cycle Operation
- Phase-Lockable Fixed Frequency: 330kHz to 750kHz
- Two 180° Out-of-Phase Controllers
- Fast Programmable Power-Up/-Down Tracking
- Programmable Current Limit Without External Current Sense Resistor
- Optional Burst Mode® Operation at Light Load
- ±1% 0.6V Voltage Reference
- External N-Channel MOSFET Architecture
- Low Shutdown Current: <100µA
- Overvoltage Protection and PGOOD Flag
- Small 28-Lead SSOP and 32-Lead QFN Packages
The LTC3802 is a dual switching regulator controller optimized for high efficiency step-down conversion from input voltages between 3V to 30V. The controller uses a leading edge modulation scheme to allow extremely low duty cycle operation. The constant frequency voltage mode controller allows a phase-lockable frequency between 330kHz and 750kHz. Power loss and noise due to the ESR of the input capacitors are minimized by operating the two controller output stages 180° out of phase. The synchronous buck architecture automatically shifts to Burst Mode operation as the output load decreases, ensuring maximum efficiency over a wide range of load currents.
The LTC3802 features an onboard, trimmed 0.6V reference and provides better than 1% regulation at the converter outputs. A separate output sense provides real time overvoltage protection and PGOOD sensing. An FBT pin programs the power-up/-down tracking between the two channels to meet various sequencing requirements. A RUN/SS pin provides soft-start and externally programmable current limit protection functions.
U.S. Patent Nos 5481178, 5846544, 6304066, 6580258, 5055767, 6307356
- Notebook and Palmtop Computers
- Portable Instruments
- Battery-Operated Digital Devices
- DC Power Distribution Systems
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 653A is a dual 15A step-down DC/DC converter featuring the LTC3802EGN. The LTC3802EGN itself is a synchronous voltage mode controller. Output #1 of demonstration circuit 653A is a 3.3V / 15A rail and output #2 is a 2.5V / 15A rail. The input voltage range is 7V to 24V.The nominal switching frequency of the LTC3802 is 550kHz and its phase lockable synchronization range is 330kHz to 750kHz.
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:
Technical Articles (2)
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.