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

The LTC3406A is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. Supply current during operation is only 20µA, dropping to ≤1µA in shutdown. The 2.5V to 5.5V input voltage range makes the LTC3406A ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery runtime portable systems. Automatic Burst Mode operation increases efficiency at light loads, further extending battery runtime.

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 LTC3406A is available in a low profile (1mm) ThinSOT package.

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 Rippe Burst Mode

LTC3406AB

Adj.

1.5MHz

Burst Mode Disabled

LTC3406AB-2

Adj.

2.25MHz

Burst Mode Disabled

Applications

* Cellular Telephones

* Wireless and DSL Modems

* Digital Still Cameras

* Media Players

* Portable Instruments

* Point of Load Regulation

* High Efficiency: Up to 96%

* Very Low Quiescent Current: Only 20µA

* Low Output Ripple Voltage During Burst Mode® Operation

* 600mA Output Current

* 2.5V to 5.5V Input Voltage Range

* 1.5MHz Constant Frequency Operation

* No Schottky Diode Required