The LTC3809EMSE-1 is a synchronous step-down switching regulator controller that drives external complementary power MOSFETs using few external components. The constant frequency current mode architecture with MOSFET VDS sensing eliminates the need for a current sense resistor and improves efficiency.
For noise sensitive applications, the LTC3809EMSE-1 can be externally synchronized from 250kHz to 750kHz. Burst Mode is inhibited during synchronization or when the SYNC/MODE pin is pulled low to reduce noise and RF interference. To further reduce EMI, the LTC3809EMSE-1 incorporates a novel spread spectrum frequency modulation technique.
Burst Mode operation provides high efficiency operation at light loads. 100% duty cycle provides low dropout operation, extending operating time in battery-powered systems.
The switching frequency can be programmed up to 750kHz, allowing the use of small surface mount inductors and capacitors.
The LTC3809EMSE-1 is available in the tiny footprint thermally enhanced DFN and 10-lead MSOP packages.
FeaturesPackageLTC3809PLL, Selectable Spread Spectrum, Power Good3x3 DFN-10, MS-10ELTC3809-1Tracking3x3 DFN-10, MS-10ELTC3808PLL, Selectable Spread Spectrum, Tracking, Power Good4x3 DFN-14, SSOP-16Feature
- No Current Sense Resistor Required
- Selectable Spread Spectrum Frequency Modulation for Low Noise Operation
- Constant Frequency Current Mode Operation for Excellent Line and Load Transient Response
- True PLL for Frequency Locking or Adjustment (Frequency Range: 250kHz to 750kHz)
- Wide VIN Range: 2.75V to 9.8V
- Wide VOUT Range: 0.6V to VIN
- 0.6V ±1.5% Reference
- Low Dropout Operation: 100% Duty Cycle
- Selectable Burst Mode®/Pulse-Skipping/Forced Continuous Operation
- Auxiliary Winding Regulation
- Internal Soft-Start Circuitry
- Output Overvoltage Protection
- Micropower Shutdown: IQ = 9µA
- Tiny Thermally Enhanced Leadless (3mm × 3mm) DFN and 10-lead MSOP Packages
Applications
- 1- or 2-Cell Lithium-Ion Powered Devices
- Portable Instruments
- Distributed DC Power Systems
(Picture: Pinout)
