Overview
Features and Benefits
- Out-of-Phase Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
- OPTI-LOOP® Compensation Minimizes COUT
- Dual N-Channel MOSFET Synchronous Drive
- ±1% Output Voltage Accuracy
- Power Good Output Voltage Monitor
- Phase-Lockable Fixed Frequency 150kHz to 300kHz
- Wide VIN Range: 3.5V to 36V Operation
- Very Low Dropout Operation: 99% Duty Cycle
- Adjustable Soft-Start Current Ramping
- Foldback Output Current Limiting
- Latched Short-Circuit Shutdown with Defeat Option
- Output Overvoltage Protection
- Remote Output Voltage Sense
- Low Shutdown IQ: 20µA
- 5V and 3.3V Standby Regulators
- Selectable Constant Frequency or Burst Mode® Operation
- Small 28-Lead SSOP Package
Product Details
The LTC1628-SYNC is a high performance dual step-down switching regulator controller that drives all N-channel synchronous power MOSFET stages. A constant frequency current mode architecture allows phase-lockable frequency of up to 300kHz. Power loss and noise due to the ESR of the input capacitors are minimized by operating the two controller output stages out of phase.
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 future microprocessor generations, and a wide 3.5V to 30V (36V maximum) input supply range encompasses all battery chemistries.
A RUN/SS pin for each controller provides both soft-start and optional timed, short-circuit shutdown. Current foldback limits MOSFET dissipation during short-circuit conditions when overcurrent latchoff is disabled. Output overvoltage protection circuitry latches on the bottom MOSFET until VOUT returns to normal. The FCB mode pin can select among Burst Mode, constant frequency mode and continuous inductor current mode or regulate a secondary winding.
Applications
- Notebook and Palmtop Computers, PDAs
- Telecom Systems
- 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)
Documentation & Resources
-
R384 Reliability Data3/26/2018PDF18 K
-
DC352A - Demo Manual9/24/2009PDF107K
Tools & Simulations
LTspice
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:
Design Resources
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.View our quality and reliability program and certifications for more information.
Part Number | Material Declaration | Reliability Data | Pin/Package Drawing | CAD Symbols, Footprints & 3D Models |
---|---|---|---|---|
LTC1628CG-SYNC#PBF | Material Declaration | Reliability Data | 28-Lead SSOP | |
LTC1628CG-SYNC#TRPBF | Material Declaration | Reliability Data | 28-Lead SSOP | |
LTC1628IG-SYNC#PBF | Material Declaration | Reliability Data | 28-Lead SSOP | |
LTC1628IG-SYNC#TRPBF | Material Declaration | Reliability Data | 28-Lead SSOP | |
Wafer Fabrication Data | R384 Reliability Data |
PCN-PDN Information
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Support & Discussions
Sample & Buy
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Lead Times
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Evaluation Boards
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.