17V, 1A Synchronous Step-Down Regulator with 3.5μA Quiescent Current

The LTC3621/LTC3621-2 is a high efficiency 17V, 1A synchronous monolithic step-down regulator. The switching frequency is fixed to 1MHz or 2.25MHz with a ±40% synchronizing range. The regulator features ultralow quiescent current and high efficiencies over a wide VOUT range.

The step-down regulator operates from an input voltage range of 2.7V to 17V and provides an adjustable output range from 0.6V to VIN while delivering up to 1A of output current. A user-selectable mode input is provided to allow the user to trade off ripple noise for light load efficiency; Burst Mode operation provides the highest efficiency at light loads, while pulse-skipping mode provides the lowest voltage ripple. The MODE pin can also be used to allow the user to sync the switching frequency to an external clock.

LTC3621 Options

Part Name

Frequency

VOUT

LTC3621

1.00MHz

Adjustable

LTC3621-3.3

1.00MHz

3.3V

LTC3621-5

1.00MHz

5V

LTC3621-2

2.25MHz

Adjustable

LTC3621-23.3

2.25MHz

3.3

LTC3621-25

2.25MHz

5V

Applications

* Portable-Handheld Scanners

* Industrial and Embedded Computing

* Automotive Applications

* Emergency Radio

* Wide VIN Range: 2.7V to 17V

* Wide VOUT Range: 0.6V to VIN

* 95% Max Efficiency

* Low IQ < 3.5μA, Zero-Current Shutdown

* Constant Frequency (1MHz/2.25MHz)

* Full Dropout Operation with Low IQ

* 1A Rated Output Current

* ±1% Output Voltage Accuracy

* Current Mode Operation for Excellent Line and Load Transient Response