Features and Benefits
- No Current Sense Resistors Required
- Out-of-Phase Controllers Reduce Required Input Capacitance
- Tracking Function
- Wide VIN Range: 2.75V to 9.8V
- 0.6V ±1% Voltage Reference
- High Current Limit
- Constant Frequency Current Mode Operation
- Low Dropout Operation: 100% Duty Cycle
- True PLL for Frequency Locking or Adjustment
- Selectable Pulse Skipping/Forced Continuous Operation
- Auxiliary Winding Regulation
- Internal Soft-Start Circuitry
- Power Good Output Voltage Monitor
- Output Overvoltage Protection
- Micropower Shutdown: IQ = 9μA
- Tiny Low Profile (4mm × 4mm) QFN and narrow SSOP packages.
The LTC3736-2 is a 2-phase dual synchronous step-down switching regulator controller with tracking that drives external complementary power MOSFETs using few external components. The constant-frequency current mode architecture with MOSFET VDS sensing eliminates the need for sense resistors and improves efficiency. Power loss and noise due to the ESR of the input capacitance are minimized by operating the two controllers out-of-phase.
Pulse-skipping operation provides high efficiency at light loads. 100% duty cycle capability 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. For noise sensitive applications, the LTC3736-2 switching frequency can be externally synchronized from 250kHz to 850kHz. An internal soft-start, which can be lengthened externally, smoothly ramps the output voltage during start-up.
The LTC3736-2 is available in the tiny thermally enhanced (4mm × 4mm) QFN and 24-lead narrow SSOP packages.
|Max Current Sense Voltage||Burst Mode||Soft Start||Spread Spectrum|
- One or Two Lithium-Ion Powered Devices
- Notebook and Palmtop Computers, PDAs
- Portable Instruments
- Distributed DC Power 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 922 is a 2-phase dual synchronous high efficiency step-down DC/DC converter featuring the LTC3736EUF-2 controller.The "-2" version features pulse-skipping (in place of Burst Mode operation) at light loads and has a tighter voltage reference accuracy over temperature when compared with the LTC3736 "plain" version. The demo board operates with a 2.7V to 8V input voltage range and provides outputs of 2.5V@5A and 1.8V@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.
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Models for the following parts are available in LTspice:
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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.