300 mA High Efficiency Low Quiescent Current Synchronous Buck Regulator With Z-mode

The 34726 is a high efficiency, low quiescent current (IQ), synchronous buck regulator, implementing Freescale’s innovative Z-mode architecture. Freescale’s Z-mode architecture greatly improves the ripple performance during light load currents, but still maintains a low quiescent current of 65μA, at no load in “Sleepy” Z-mode.

The 34726 accepts an input voltage in the range of 2.7 to 5.5 V, making it ideally suited for single cell Li-Ion based applications. Factory preset output voltages, ranging from 0.8 to 3.3 V, reduce the number of required auxiliary components. The part is able to provide 300 mA of continuous load current across the input and the output voltage ranges.

The 34726 switches at 2.0 MHz to allow the use of small, surface mount inductors and capacitors to save precious board space.

The 34726 is available in the small, space saving, and low cost, 2x2 UDFN-8 packages. The part is guaranteed for operation over the -25°C to 85°C temperature range.

Features

• 94 peak efficiency

• 2.0 MHz switching frequency

• 2.7 to 5.5 V input voltage range

• Automatic transition to energy saving light load Z-mode (low ripple)

• Fixed output voltage options from 0.8 to 3.3 V

• 65 μA quiescent current during sleepy Z-mode

• 300 mA maximum continuous output current

• Internal 2.0 ms soft start

• Thermal and over-current protection

• 0.1 μA quiescent current in shutdown (disabled)

• Ultra thin 2x2 UDFN package

• Pb-free packaging designated by suffix code FC