I am using adum5000. the VDD1 is supply with 3.3v.
I notice when i supply 3.3v to adum5000, Viso measures around 1.6v and after many seconds will increase to 3.3v?
Would need help why this happen?
I will need some more information to try to see what could be wrong:
1. A schematic of your circuit of the ADuM5000.
2. A waveform of the VDD1 startup and VISO voltage.
3. What is the load on VISO in startup?
4. The data code on the ADuM5000 part.
Attached are the schematics.
Some additional infos.
The board wakes up for approximate 3sec and goes to sleep. The LTC1754-3.3v
will be pulled low at the SHDN pin. LTC1754-3.3 is providing the 3.3v to my
- The waveform for VDD1 and Viso is a straight line at 3.3v
- The load on Viso is at 125mA on startup and drops to 89mA while running
- The data code is
I saw this from LTC1754, could it this feature which allows the charge pump
to provide the needed current by ADum5000?
On Tue, Dec 20, 2016 at 12:48 AM, bkennedy <
Looking at your circuit, the LTC1754ES6-3.3V is only rated for 40mA Iout, and this powers the ADuM5000 which in startup you say Viso load is 125mA, so the current at VDD1 will be much more than 125mA and therefore the Viso load will be too much.
1. Even 89mA Viso load is too much, the ADum5000 at 3.3V to 3.3V is only rated for 60mA.
2. Can you provide a scope waveform of Viso load measurements?
3. Can you provide a scope waveform of Viso and VDD1 in startup and in operation?