Hello,
I need some help with an inductorless design.
I've read the information in this posthttp://support.dialog-semiconductor.com/disable-buck-converter
However I still have some questions on the power supply configurations.
Is it possible to run only on 1.8V?
ie:
-SWITCH = open
-VBAT3V = VBAT3V_RF = VBAT1V = VDCDC = VDCDC_RF = 1.8 Vmax
Operate in BOOST mode?
Alternatively if
-SWITCH = open
-VBAT3V = VBAT3V_RF = VDCDC = VDCDC_RF = 2.8 Vmax
Can I set VBAT1V to 1.8V for 1.8V I/O operations?
Thank you,
Da Shen
Device:
Hi gurushen,
When the 580 operates without an inductor the supply voltage is more restricted, the recommended and tested power supplies are indicated in the post you are refering to. When the 580 operates without an inductor the DCDC converter is disabled so actually there is no BUCK/BOOST mode, the two different configurations that are indicated from the post (start in boost/ start in buck) is the mode that the 580 will virtually function in order to trick the bootloader when performs the necessary checks.
Thanks MT_dialog
Thanks MT_dialog,
Can I use only 1.8V for the supplies though? This line from the datasheet "Note: The system should never be cold booted when the supply voltage is less than 2.5 V. A manual power up with a power supply less than 2.5 V in buck mode might create instability." seem to indicate I can not do that. As I understand the OTP LDO needs 2.5V?
Hi gurushen,
Yes the OTP LDO needs at least 2.5V in order to operate but in order to operate. According to the designers, when the DCDC converter is disabled one has to apply the voltages mentioned in the post, thus only 1.8V available will not work.
Thanks MT_dialog
Thank you. So can a supply between 2.5 to 3.3v work or it has to be 3.3v?
Hi gurushen,
Yes you can apply from 2.4V min to 3.3V max. In this threadhttp://support.dialog-semiconductor.com/disable-buck-converteron my second post there is an attachment that mentions the external power that can be applied when no converter is used. Please have a look.
Thanks MT_dialog