Users Manual

19/05/2019 Pyboard D-series reference — Pyboard D-series 1.0 documentation
https://pybd.io/hw/pybd_sfxw.html 4/8
Forbestperformanceprovide3.4VonVIN(3.3Visalsookbut3.4Vwillbenefitfrom
LDOfiltering).IfthereisachancethattheUSBport(orVUSB)willprovidepoweras
wellasVIN,thenVINshouldbeprotectedwithadiode(egSchokydiodeoraFET
reverseprotector).
Ifsupplyvoltageis5VtheneitherprovideitonVUSB(onlyavailableontheX‑posion
through‑holes)orputadiodeinlineandfeedintoVIN(diodeshoulddropvoltageto
4.8Vorbelow).
Asummaryofthepowerportsisprovidedinthetablebelow.Forfulldetailspleaseconsult
theschemacs.
Warning:IftheUSBhostportwhichpowersPYBDiscapableofdeliveringmorethan1A,a
shortcutonVINwouldtripthebuilt‑infuseonthePYBD.
Note:VINmayalsobeusedasanonswitchablepowersupplyoutputaslongastotalcurrent
isbelow1A.
Power control
The3V3outputportisconnectedinternallytoanLDOwhichisswitchableonandoffviathe
Pin('EN_3V3') pin.Itisturnedonbydefaultduringthebootsequence.
TheCPUfrequencycanbesettoanymulpleof2MHzbetween48MHzand216MHz,via
machine.freq(<freq>) .BydefaulttheSF2modelrunsat120MHzandtheSF6modelat
144MHzinordertoconserveelectricity.Itispossibletogobelow48MHzbutthentheWiFi
cannotbeused.
Filesystem
ThePYBDhasaninternal2MiBfilesystemwhichisFATformaedandavailabletoPythonat
thepath
'/flash' .Theunderlyingblockdeviceforthisfilesystemisavailableviathe
pyb.Flash() object.
USB ports
Port Use Voltage Notes
USBconn powerandcomms 5V connecttoPCorUSBpowerbrick
VUSB powerin 4.8V‑5.2V 1Afast/0.22Ohmfuseandprotecvediode
VIN powerin 3.2V‑4.8V alsoonWBUS
VBAT backupbaery 1.65V‑3.6V alsoonWBUS
3V3 outputonly 3.3V userswitchableLDOmax300mAtotal