LTC1773 - Synchronous Step-Down DC/DC Controller
The LTC1773 is a current mode synchronous buck regulator controller that drives external complementary power MOSFETs using a fixed frequency architecture. The operating supply range is from 2.65V to 8.5V, making it suitable for 1- or 2-cell lithium-ion battery powered applications. Burst Mode operation provides high efficiency at low load currents. 100% duty cycle provides low dropout operation which extends operating time in battery-operated systems.
The operating frequency is internally set at 550kHz, allowing the use of small surface mount inductors. For switching-noise sensitive applications, it can be synchronized up to 750kHz. Peak current limit is user programmable with an external high side sense resistor. A SYNC/FCB control pin guarantees regulation of secondary windings regardless of load on the main output by forcing continuous operation. Burst Mode operation is inhibited during synchronization or when the SYNC/FCB pin is pulled low to reduce noise and RF interference. Soft-start is provided by an external capacitor.
Synchronous rectification increases efficiency and eliminates the need for a Schottky diode, saving components and board space. The LTC1773 comes in a 10-lead MSOP package.
Features
Typical Application  | Applications
Packaging |
Order Information
| Part Number | Package | Temp | Price(1-99) | Price (1k)* |
|---|---|---|---|---|
| LTC1773EMS#PBF | MS-10 | E | $2.90 | $2.50 |
| LTC1773EMS#TRPBF | MS-10 | E | $2.56 |
Demo Boards
| Part Number | Description | Price |
|---|---|---|
| DC309A | LTC1773EMS | 3A Synchronous Buck Regulator, 2.8V to 8.5V Input, 1.5V/1.8V/2.5V/3.3V @ 2.5A avg / 3A peak | $100.00 |
| DC431A | LT1725CGN LTC1773EMS | Telecom Input, Isolated 3 Output DC/DC Converter, +36V to +72V Input, Vout = 5V/1A, 3.3V/5A, 2.5V/4A | Contact Factory |
