| UCD9248： three UCD9248 can’t be scanned at the same time | |
| Part Number: UCD9248 I am usingcompany 's software Fusion Digital Power Designer to configure UCD9248. My hardware schematic is same with the Xilinx KC705 board. There are three UCD9248 on my board. When I connect the PC and my board with TI's USB-to-GPIO, the three UCD9248 can’t be scanned at the same time, and in most cases only one UCD9248 is scanned. In the kc705 board, the 1-pin voltage of the transistor FCX491A is 4.0v, and the 3-pin voltage is 3.3v, but the measured results of our board are 3.3v and 2.7v respectively.According to the UCD9248 datasheet, the voltage of V33FB port is 4-4.6v, and the voltage of V33D port is 3.3-3.6v. At first, I thought that the voltage of the my board was insufficient to supply UCD9248, so it could not be scanned. Therefore, the power supply circuit of the first UCD9248 was adjusted. When the resistance R3 was changed to 2K, the same voltage value as Xilinx KC705 board could be obtained. However, the scan results did not change. The second question is when the first chip is scanned, the address is not the same as the theoretical value. The addr-0 and addr-1 pins are connected with 75K resistors . The theoretical address value is 52, but when it is scanned, the address value is 42. The address values of the other two UCD9248 are the same as the theoretical values. Please give me some suggestions. Thank you very much. | |
| Hello, Which Fusion version are you using? Thanks Qian | |
| Hello,Qian,we use Fusion Digital Power Designer 7.2.1. Thanks. | |
| Hi, I don't know why address 52 is scanned as 42. Can you double check the resistor value? For the issue that Fusion can not find all devices, I'm checking with Fusion team if they have any idea. As a work around solution, you can let Fusion to scan device at particular address. By this way, they can find device at any address. For example, at below screenshot, the Fusion will only scan the part at address 52. | |
| Hi, 1. The issue with scanning 3 devices at the same time and can only detect one: might due to devices' addresses (#2 below) => communication issue. Try fixing #2 and see if #1 is also fixed. 2. The issue with device's theoretical address (52) being scanned as 42 might due to resistor tolerance. Try using different resistors, avoid using resistor at the boundary such as 75 kOhm. Due to resistor tolerance and voltage level, address bin might be 4, or 5, or 3. Try, for example, resistor 68 kOhm (between 75K and 64.9K) and see if it fix the issue. Regards Anne Ngo customer organization | |