STM32F4xx small size

[tm3341]

Posted on February 25, 2015 at 00:53

Hi,

do you (ST) have in plan to make a small footprint STM32F4xx devices?

Like 32 or 48 pins?

There are times when you just need a lot of power (FFT, DSP) but not so much pins.

Like STM32F446 is a great, but unfortunatelly, not smaller than 64 LQFP.

32 or 48 LQFP would be top score.

What about that?

#footprint #lqft32 #packa #lqfp48

[Tesla DeLorean]

Posted on February 25, 2015 at 01:39

Well you've got a couple of problems with commercial viability, and an ability to get enough functionality out of the diminishing number of pins.

The pin mux strategy for STM32 has always been difficult, as the pin count drops the number of usable peripheral combinations drops. The parts from the F0 series in small leaded packages are functionally crippled devices.

Cost drivers dictate all the units use the same die, or a very low number of die. Hobbiests get cheap parts because someone else is buying millions of devices.

Commercial clients wanting small parts in quantities that are remotely interesting are capable of designing/building with 7x7mm UFBGA144 or 4x4mm WSCLP81

[Uwe Bonnes]

Posted on February 26, 2015 at 12:32

Die size may also be to large for a smaller package...

[waclawek.jan]

Posted on February 26, 2015 at 12:49

> Die size may also be to large for a smaller package...

I thought about that too; but as the WLCSP package is roughly 3x4mm, that should fit into LQFP48, unless some issue with the pads arrangement/bonding constraints.

JW

[raptorhal2]

Posted on February 26, 2015 at 18:15

Check out the F3 series. A 48 pin F303 package which includes hardware floating point might be what you can use.

Cheers, Hal

[Chris1]

Posted on February 26, 2015 at 21:12

The STM32F411 Datasheet indicates available 49 and 48 pin packages:

  WLCSP49, 3.034 x 3.22 mm, 0.4 mm pitch wafer level chip size package

  UFQFPN48, 7 x 7 mm, 0.5 mm pitch package

STM32F411 has Cortex-M4 CPU with FPU, operating at up to 100 MHz.

[Tesla DeLorean]

Posted on February 26, 2015 at 21:26

I'm sensing more of a desire for 180 MHz, with 2 Mbyte of FLASH and 256 Kbyte of SRAM.

And I can understand the appeal. Now we just need Apple, or someone, to need a low pin count one in a TV remote, phone charger or something.

It would be interesting to see some pins/package vs sale numbers graph.