1. Cause

Now Artery chip comes to opensource flight controoler design, which will break the monopoly position of STM32.
And it benifits the community of aircraft model industry. STM32F405 is a very popular chip in the industry.
Within the budget of manufacture cost, chip set comparison between STM32F405 and AT32F435 appears particularly important.

So we are trying to evaluate these two chips according to their specification for opensource flight controller.

2. Performance & Memories

Items	STM32F405RGT6	AT32F435RGT7
UID	$✓$	$✓$
CRC	$✓$	$✓$
FPU&DSP	$✓$	$✓$
M4 Core	168 MHz	288 MHz
SRAM	192+4 Kbytes	384 Kbytes
Flash	1024 Kbytes	1024 Kbytes
Power	1.8 V to 3.6 V	2.6 to 3.6 V
Temp	–40 to +105 °C	–40 to +105 °C

3. IO Extensibility

Items	STM32F405RGT6	AT32F435RGT7
AD	3×12-bit 24 chan @2.4 MSPS	3×12-bit 24 chan @5.33 MSPS
IO	51	53
I2C	3	3
UART	4 USARTs/2 UARTs	4 x USARTs + 4 x UARTs
SPI	3	4
CAN	2	2
SDIO	1	2
DMA	16-stream	22 chan
timer	17	18

4. Package & Form Factor

Items	STM32F405RGT6	AT32F435RGT7
QFN48	$\mathrm{X}$	$✓$
LQFP48	$\mathrm{X}$	$✓$
LQFP64	$✓$	$✓$
LQFP100	$✓$	$✓$
LQFP144	$✓$	$✓$
LQFP176	$✓$	$\mathrm{X}$
UFBGA176	$✓$	$\mathrm{X}$
WLCSP90	$✓$	$\mathrm{X}$

5. Pin2Pin Comparison

There is little difference between STM32F405RGT6 and AT32F435RGT7.

• STM32F405RGT6 : VCAP_1/VCAP_2
  

• AT32F435RGT7: PH3/PH2
  
  

• 引脚功能定义：根据飞控应用进行核对，特别注意！！！

6. Conclusion

It is a great choice of choosing AT32F435 as a replacement of STM32F405 flight controller within the budget of manufacture cost.

Note: There still needs more numbers for flight contoller’s dynamic performance.

7. Reference

【1】STM32F405/415
【2】AT32F435 Series

8. Additional Information

With more and more features are developed by the community, it’s limited by flash storage of 1MB. Artery F435 chip can simply support up to 4MB size, this is a great advantage.

9. Appendix

Debut Hits Peak! ARTERY Launches Ultrahigh Performance AT32F435/437 Series Cortex®-M4 MCU