The LTC3568 from Analog Devices (originally Linear Technology) is a high-efficiency, 1.8 A, constant-frequency synchronous step-down DC/DC converter. Synchronous rectification (internal high- and low-side MOSFETs, ~0.11 Ω R_DS(ON)) and a high switching frequency let it run small external components at high efficiency. LTC3568EDD#PBF is the 10-lead 3x3 mm DFN with exposed pad, lead-free version.

It operates from a 2.5 V to 5.5 V input (PVIN/SVIN), making it a natural fit for single-cell Li-ion and 3.3 V/5 V rails, and delivers up to 1.8 A continuous with a ~2.4 A peak current limit. The switching frequency is programmable from 0.85 MHz to 4 MHz by an external resistor on SHDN/RT, trading size against efficiency, and the SYNC/MODE pin allows external clock sync and selection of Burst Mode, pulse-skipping or forced-continuous operation.

The output is set from 0.8 V to 5 V by an external R1/R2 divider to the V_FB pin (0.8 V reference); the ITH pin sets the loop compensation. A PGOOD open-drain flag signals when the output is in regulation, and the device includes undervoltage lockout, cycle-by-cycle current limit, short-circuit and thermal protection. The exposed pad is GND and the thermal path and must be soldered. With up to 96% efficiency, the LTC3568 fits compact, battery-powered point-of-load designs.

Note: Values are taken from the ADI/Linear LTC3568 datasheet. Confirm every parameter against the latest official documentation before committing a design.

LTC3568EDD#PBF is supplied in the 10-lead DFN (3 mm x 3 mm, DD) with exposed pad; "#PBF" marks the RoHS-compliant lead-free finish. The exposed pad on the bottom is the GND connection and the main thermal path - it must be soldered to a board copper pour with thermal vias. Keep the SW node and input capacitor loop tight, separate SGND and PGND returns and join them at the pad, and place the feedback divider close to V_FB. Package dimensions and pin-1 orientation are shown below.

📄 Full specifications are detailed in the official ADI/Linear LTC3568 datasheet.

The 10-lead DFN brings out the power, switching and control pins, plus the exposed pad:

• Pin 1 - SHDN/RT: Shutdown / frequency-set resistor.
• Pin 2 - SYNC/MODE: Sync input / mode select (Burst / pulse-skip / forced-continuous).
• Pin 3 - SGND: Signal ground.
• Pin 4 - SW: Switch node (to the inductor).
• Pin 5 - PGND: Power ground.
• Pin 6 - PVIN: Power input voltage.
• Pin 7 - SVIN: Signal input voltage.
• Pin 8 - PGOOD: Power-good open-drain output.
• Pin 9 - VFB: Feedback input (0.8 V reference, R1/R2 divider).
• Pin 10 - ITH: Error-amplifier output / loop compensation.
• EP - Exposed Pad: GND and thermal path, must be soldered.

Pin 1 is marked below; the exposed pad (EP) is the center pad.

The parts below are related ADI/Linear synchronous step-down regulators in our catalog. They are not all drop-in replacements; verify input range, current, frequency and pinout before substituting.

Selection Tips: Use the LTC3568 for a single 1.8 A, up-to-4 MHz synchronous buck from a 2.5-5.5 V rail. The LTC3411A is a similar 1.25 A part, the LTC3414 a higher-current 4 A part, the LTC3548A a dual-output version, and the LTC3406A a lower-current 600 mA buck in ThinSOT.

Linear Technology, now part of Analog Devices, is known for high-performance power management. The LTC3568 is a compact high-frequency synchronous buck that integrates both power MOSFETs, delivering high efficiency in a small 3x3 mm DFN for portable rails.

The device is backed by full datasheet characterization and application notes on frequency selection, mode configuration, feedback design and grounding/thermal layout of the exposed pad - the details that determine an efficient, low-noise portable supply.