Any USB/Ethernet controller suggestions?

[john swift]

the extra 0.1V from your 5.1V power supply is not a problem

for 5V logic like the old 74series TTL logic
the limits for nominal 5V supply voltage is between the 4.75 min and 5.25V max

for 5V Atmel 8 bit micro controllers like the ATmega8 operating voltage is 4.5V to 5.5V

John

PS
any one know which micro controller has been used for the UC300ETH ?

[m_c]

As John says, that voltage sounds fine. It could even be your multimeter that's slightly out.


I would guess the UC300 is using some form of ARM chip, regardless I'd guess whatever chip will be running at 3.3V. Even a few years ago, the vast majority of microcontrollers were running at 3.3V max, with 5V capable ones being a dying breed.

[john swift]

m_c
your correct the micro controller is a 3.3V device


looking at a photo of the UC300 it has a
MICROCHIP dsPIC33EP256



from the MICROCHIP web site
Operating Voltage Range (V)
3 to 3.6

the dsPIC33EP256 Input/Output

• Sink/Source 10 mA on All Pins
• 5V Tolerant Pins
• Selectable Open-Drain, Pull-ups and Pull-Downs
• Up to 5 mA Overvoltage Clamp Current
• External Interrupts on All I/O pins

the UC300 board has a 5V supply connector
so the surface mount device between the 5V supply and PIC
must be a low drop out 3.3V regulator

John