how about the driving capability of REG33V of 908JW32?

[jjl3]

I can't find the description about this information in the datasheet of MC68HC908JW32.

I want to use it as a 3.3V power supply for a RF IC to save a LDO.

whether can I do as above?

in addition, if I use VDD(5V) as Vtst to connect to pin IRQ of 908jw32, whether can 908jw32 enter monitor mode ?

Thanks & best regards

Ji

[jjl3]

Thanks Mr ok2ucx a lot!

[ok2ucx]

Hallo Ji,

HC908JW32's 33VREG pin cannot drive anything external. Its purpose is only for internal power supply for USB. Simple answer is no. I only guess that this voltage might be used just as a reference if you have some power component (OpAmp, transistor) available in you design.

To enter the monitor mode of HC908JW32, you need to apply 7.5-8V onto IRQ pin (plus some other logic levels on other pins). 5V is not enough. You may have a look in ZSTAR ref. design (RD3152MMA7260Q) to see what's the monitor mode interface in the real application. Unfortunately there's no default USB bootloader that could be used ;-( So that's why AN2295 bootloader has been adopted for USB with JW32 on ZSTAR.

Regards, Pavel ok2ucx

Freescale CZ