1.5MHz, 600mA Synchronous Step-Down Regulator in ThinSOT

The LTC3406 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. The device is available in an adjustable version and fixed output voltages of 1.5V and 1.8V. Supply current during operation is only 20µA and drops to ≤1µA in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3406 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. Automatic Burst Mode® operation increases efficiency at light loads, further extending battery life.

Switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors.

The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.6V feedback reference voltage. The LTC3406 is available in a low profile (1mm) ThinSOT package.

Protected by U.S. Patents, including 6580258, 5481178.

VOUT

FSW

Features

LTC3406

Adj.

1.5MHz

Burst Mode

LTC3406-1.2

1.2V

1.5MHz

Burst Mode

LTC3406-1.5

1.5V

1.5MHz

Burst Mode

LTC3406-1.8

1.8V

1.5MHz

Burst Mode

LTC3406B

Adj.

1.5MHz

Burst Mode Disabled

LTC3406B-1.2

1.2V

1.5MHz

Burst Mode Disabled

LTC3406B-2

Adj.

2.25MHz

Burst Mode Disabled

LTC3406A

Adj.

1.5MHz

Low Ripple Burst Mode

LTC3406AB

Adj.

1.5MHz

Burst Mode Disabled

LTC3406AB-2

Adj.

2.25MHz

Burst Mode Disabled

Applications

* Cellular Telephones

* Personal Information Appliances

* Wireless and DSL Modems

* Digital Still Cameras

* MP3 Players

* Portable Instruments

* High Efficiency: Up to 96%

* Very Low Quiescent Current: Only 20µA During Operation

* 600mA Output Current

* 2.5V to 5.5V Input Voltage Range

* 1.5MHz Constant Frequency Operation

* No Schottky Diode Required