DA9211 datasheet(34/74 Pages) DIALOG

34 / 74 page

DA9211 and DA9212

Datasheet

Company confidential

Data sheet

Version <3.0>

<07-Jan-2015>

CFR0011-120-00 Rev 3

34 of 74

In Track Mode, the content of the VBUCKA_SEL bit is ignored, as well as VBUCKA_A and

VBUCKA_B bits. They will become active again once the voltage track mode is disabled. The GPI0

does not generate any event in this case.

Figure 35: Concept of control of the buck

’s output voltage

Soft Start up

13.1.4

To limit in-rush current from VSYS, the buck converters can perform a soft-start after being enabled.

The start-up behaviour is a compromise between acceptable inrush current from the battery and

turn-on time. In DA9211 and DA9212, different ramp times can be individually configured for each

buck converter on register BUCKA_UP_CTRL and BUCKB_UP_CTRL. Rates higher than 20 mV/µs

may produce overshoot during the start-up phase, so they should be considered carefully.

A ramped power-down can be selected on register bits BUCKA_DOWN_CTRL and

BUCKB_DOWN_CTRL. When no ramp is selected, the output node will be discharged only by the

pull-down resistor, if enabled via BUCKA_PD_DIS and BUCKB_PD_DIS.

Current Limit

13.1.5

The integrated current limit is meant to protect DA9211 and DA9212

’s power stages and the external

coil from excessive current. The bucks

’ current limit should be configured to be at least 40% higher

than the required maximum continuous output current (see table below).

When reaching the current limit, each buck converter generates an event and an interrupt to the host

processor unless the interrupt has been masked using the OCx_MASK controls. These OCA_MASK

and OCB_MASK control bits can be used to mask the generation of over-current events during DVC

transitions. An extra masking time as defined in OCx_MASK will be automatically added to the DVC

interval after the DVC has finished in order to ensure that the possible high current levels needed for

DVC do not influence the event generation.

DA9211 Datasheet(PDF) 34 Page - Dialog Semiconductor