Features and Benefits
- Dual, 180° Phased Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
- Tracking for Both Outputs
- Constant Frequency Current Mode Control
- Wide VIN Range: 4.5V to 28V Operation
- Power Good Output Voltage Indicator
- Adjustable Soft-Start Current Ramping
- Foldback Output Current Limiting-Disabled at Start-Up
- No Reverse Current During Soft-Start Interval
- Clock Output for 3-, 4-, 6-Phase Operation
- Dual N-Channel MOSFET Synchronous Drive
- ±1% Output Voltage Accuracy
- Phase-Lockable Fixed Frequency 260kHz to 550kHz
- OPTI-LOOP® Compensation Minimizes COUT
- Very Low Dropout Operation: 99% Duty Cycle
- Output Overvoltage Protection
- Small 28-Lead SSOP and 5mm × 5mm QFN Packages
The LTC3828 is a dual high performance step-down switching regulator controller that drives all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows for a phase-lockable frequency of up to 550kHz. The TRCKSS pin provides both soft-start and tracking functions. Multiple LTC3828s can be daisy-chained in applications requiring more than two voltages to be tracked.
OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The precision 0.8V reference and power good output indicator are compatible with a wide 4.5V to 28V (30V maximum) input supply range, encompassing all battery chemistries.
The RUN pins control their respective channels independently. The FCB/PLLIN pin selects among Burst Mode® operation, skip-cycle mode and continuous current mode. Current foldback limits MOSFET dissipation during short-circuit conditions. Reverse current and current foldback functions are disabled during soft-start.
- Telecom Infrastructure
- ASIC Power Supply
- Industry Equipment
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 (3)
The DC980A and DC980B are a demonstration system that showcases the LTC2970, a dual power supply monitor and margining controller with an I2C interface. The DC980A board contains the LTC2970 device and the DC980B board contains the LTC3828 dual DC/DC controller. The two boards interface to each other via a 20-pin connector. The DC980B board features the LTC3828 dual output, 2-phase synchronous buck regulator. The LTC2970’s two voltage-buffered, 8-bit IDACs allow highly accurate margining of the LTC3828’s output voltages. The IDACs can be configured to automatically servo the power supplies to a desired voltage using the ADC for feedback. The DC980B comes preconfigured with 3.3V and 5V power supply rail voltages.
Demonstration circuit 884 is a high current density supply featuring the LTC3828EUH, a dual-output, 2-phase synchronous buck controller. The input voltage of the demo board is from 4.5V to 15V. The outputs are 2V @ 17A and 1.5V @ 17A.
Demonstration circuit 802 features the LTC3828EUH, a dual-output, 2-phase synchronous buck controller. The input voltage range of the demo board is 7V to 21V. The outputs are 5V @ 5A and 3.3V @ 5A.
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:
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.