Fixed Ratio High Power Inductorless (Charge Pump) DC/DC Controller
Features and Benefits
- Wide VIN Range: 10V to 72V (80V ABS Max)
- Soft Switching for Low Noise Operation
- Phase-Lockable Fixed Frequency 200kHz to 1.5MHz
- ±1% Output Voltage Accuracy
- RSENSE or DCR Current Sensing
- Programmable CCM, DCM, or Burst Mode® Operation
- CLKOUT Pin for Multiphase Operation
- Short Circuit Protected
- EXTVCC Input for Improved Efficiency
- Monotonic Output Voltage Start-Up
- Optional External Reference
- 32-Pin (5mm × 5mm) QFN
The LTC7821 uses a proprietary architecture that merges a soft switching charge pump topology with a synchronous step-down converter to provide superior efficiency and EMI performance compared to traditional switching architectures.
In a typical 48V to 12V application, efficiency of greater than 97% is attainable with the LTC7821 switching at 500kHz. The same efficiency can only be achieved with a traditional controller switching at one-third the frequency. Higher switching frequencies allow the use of smaller inductances that yield faster transient response and smaller solution size.
The LTC7821 can be easily paralleled to provide higher output currents with its accurate current sharing capability and frequency synchronization function.
- Intermediate Bus Converters
- High Current Distributed Power Systems
- Telecom, Datacom, and Storage 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 2513A is a high efficiency, high power density hybrid converter. It can deliver 12V/20A with an input voltage from 36V to 72V. This demo board features the LTC7821, which uses an architecture that merges soft-switching switched-capacitor topology with a traditional step-down converter to provide superior efficiency compared to the traditional switching architectures. It offers a high efficiency/high density and cost effective solution for non isolated intermediate bus applications in power distribution, datacom and telecom as well as emerging 48V automotive systems.
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:
Product Selector Card (1)
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.