DA9021 datasheet(90/142 Pages) DIALOG

90 / 142 page

DA9021/22

System PMIC with high efficiency USB power manager

Datasheet

Revision 2.5

17-Feb-2017

CFR0011-120-00 Rev 5

90 of 142

VBUCKCORE

SWBUCKCORE

40uF

SWBUCKPRO

Symmetrical

connection

Figure 41: BUCKCORE merged with BUCKPRO

18.2 Converter BUCKPERI with OTP programmable output voltage and

bypass mode (DA9022 only)

The BUCKPERI converter is a high efficiency synchronous step down regulator operating at a high

frequency (2 MHz). The default output voltage is loaded from OTP and can be set from 1.8 V to 3.6 V

in 50 mV steps from 1.8 to 3.0 V and 100 mV steps from 3.0 V to 3.6 V.

NOTE

Changes to the output voltage have to be executed in disabled mode as this regulator does not offer DVC

The supply current during PWM mode operation is in the order of 3 mA (quiescent current and

charge/discharge current) and drops to < 1 µA in shutdown. Switching frequency is chosen to be high

enough to allow the use of a small 2.2 µH to 4.7 µH inductor.

The operating mode of the buck converter is selected via the buck control register bits. The buck

converter can be forced to operate in either SYNCHRONOUS mode or SLEEP mode. Additionally

the buck converter has an AUTOMATIC mode where it will switch between SYNCHRONOUS and

SLEEP mode depending on the load current.

In SLEEP mode, the buck converter works in PFM mode.

An internal zero crossing comparator is used to time the turn-off of the NFET, thereby removing the

need for an external Schottky diode.

If reduced output power is required for improved efficiency it can run with a smaller pass device.

BUCKPERI is able to operate up to a duty cycle of 100%, where a bypass switch across the coil will

be enabled to prevent LC oscillations introduced by load-current spikes.

DA9021 Datasheet(PDF) 90 Page - Dialog Semiconductor