Can anyone help?
found this chip on microchip, but dont understand what the FG and Rprog pins do, despite reading the description on the datasheet.. would like to use them for a small bldc motor for a quadcopter..

Datasheet on Microchip:
http://ww1.microchip.com/downloads/en/DeviceDoc/20002281B.pdf

Motors to be used are potentially this:
http://hobbyking.com/hobbyking/store/__9663__HobbyKing_AP_03_7000kv_Brushless_Micro_Motor_3_1g_.html
or this:
http://hobbyking.com/hobbyking/store/__9068__Turnigy_1220_Brushless_Inrunner_Motor_10300kv.html
i suspect the latter as it could be fit into a hubsan frame without too much modification i suspect.
please help!
Cheers,
Chris

Correction - The link is for MTD6505, i got the title wrong!! edited 2209

 

The link is for a MTD6505 not a MCP8024?
Which are you using?
Max.

 

Sorry, i was looking at both as the 8024 has built in regulators,
i mean the MTD6505 due to its small size and external components, sorry!

 

*bump*
anyone?

 

FG is an open drain output to signal the fan speed, presumably by the frequency of pulses. If you don't need it just don't connect anything to it. If you do need it use a pullup of 10K or so to Vdd and take the output from FG.

Rprog is programming the back EMF of the fan. Section 4.9 tells you how to determine this by blowing air through the fan and looking at what it outputs on an oscilliscope. You then look up the computed Km and use the resistor from table 4-2 to ground.

Hope this helps.

Bob

 

hi bob, that does help.. but does that mean that i can only use the chip for a fan bldc motor?
i posted a link above (and again below) of a small micro motor i wanted to use with the driver IC, but if it has to be a fan ill go back to drawing board
http://hobbyking.com/hobbyking/store/__9068__Turnigy_1220_Brushless_Inrunner_Motor_10300kv.html