I'm having a problem with my I2C bus and the LTC2992.
I've built a prototype board and found out that the reason why I could not get any ACK from it was that I had not connected SDAI to SDAO. I verified this with a USB to I2C interface, just to confirm I was getting data back. wasn't concerned as to what data, so long as it spoke to me and was not a NACK error.
The application is for a micro controller to communicate with the LTC2992 and then transmit that data to a serial terminal over UART via a USB-UART cable. However when I connect SDAI to SDAO it kills the communications to the serial terminal, but when I remove the link, the serial terminal works and data about other devices on the board is displayed, but not the LTC2992 - as you would expect.
its like the device is causing the I2C bus to be held. This was confirmed by my colleague developing the firmware for the micro, who stated the his I2C services were stopping cos if a hardware change I had made (pin 10 - 11 link)
I've read the datasheet and made sure its not the LTC2292-1 (which it isn't) but am wondering if it could be the under voltage lockout feature. I've tried reading the datasheet on this feature but am confused as to what conditions must be applied to Vdd and INTVcc. I have set up the IC as per figure 4c in the datsheet.
My questions are:
- have i misunderstood the connections for SDAI and SDAO?
- in regards to the under-voltage lockout feature, must I
- power the chip on as normal and then toggle Vdd + INTVcc?
- toggle either Vdd or INTVcc?