AS3701 datasheet(14/110 Pages) AMSOSRAM

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[v1-11] 2016-Dec-14

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AS3701 − Detailed Description – Power Management Functions

High-Efficiency Operation (Default Setting)

High-efficiency operation is enabled by setting the bit sd_low_

noise [SD_control1] to 0.

In this mode there is a minimum coil current necessary before

switching OFF the PMOS. Resultant there are less pulses

necessary at low output loads, and therefore the efficiency

increases. As drawback, this mode increases the ripple up to a

higher output current.

Figure 13:

Switching Behavior at Operating Point 1

Operating Point 1: These graphs show the switching behavior referring to the operating point 1 from figure10.

Here the mode is set to high efficiency operation and the DCDC is in skipping mode at 2mA load current. Here a

minimum coil current during the PMOS ON time is needed, hence more energy can be stored, the duration

between the bursts is longer and the efficiency increases.

Figure 14:

Output Voltage Ripple Measurement at Operating Point 3

Operating Point 3: These graphs show the switching behavior referring to the operating point 3 from figure10.

Here the mode is set to high efficiency operation and comparing to operating point 4 the DCDC is still in skipping

mode at 10mA load current and keeps the efficiency higher.

AS3701 Arkusz danych(PDF) 14 Page - ams-OSRAM AG