I was evaluating the 812 tssop20
5v from the usb dongle is zener'd (I assume - there is a diode on the pcb)
down to approx 3.1v.
I connected an LED VSS to VDD and the voltage dropped about 150mv or so
The LED was drawing approx 3.6ma (per my Harbor Freight/Centec DMM)
what power is available - considering the size of the traces and SMT diode ??
I want to connect a 1K pot, some I2C resisters, and a 3 terminal temp sensor to it.
an LED possibly - (definitely for troubleshooting)
LPC812 - on board power availability
Re: LPC812 - on board power availability
Love those Harbor Freight Centec meters, it is part of my recommendations for a lab.
Yes there is a 2V Zener diode on the board that drops the 5V to a nominal 3V. It takes advantage of the wide power supply range of the LPC812.
I wouldn't try to power a whole lot of stuff, but the diode is rated at 150mW so that is 75 mA at 2V, and the LPC812 takes less than 5mA. And by using a diode you can always have an external 3.3V regulator to power the chip and system.
Yes there is a 2V Zener diode on the board that drops the 5V to a nominal 3V. It takes advantage of the wide power supply range of the LPC812.
I wouldn't try to power a whole lot of stuff, but the diode is rated at 150mW so that is 75 mA at 2V, and the LPC812 takes less than 5mA. And by using a diode you can always have an external 3.3V regulator to power the chip and system.