I received the following from my customer today:
Our SBC design consist of two boards, one with the OMAP3530 and TPS65950 and the other is a daughter board which generates 4.2V to power up the TPS65950 which eventually powers up the OMAP3530. The design looks great because it have been reviewed internally and by a third party and problem has arose but the problem is with the TPS65950. It receives the 4.2V required to power it up but its outputs are very unstable. From the oscilloscope, I observed that the vio(1.8V) stays on for about 4ms, VDD2 stays for about 2ms and VDD1 stays for about 1ms and they all collapse to zero. Sometimes it powers up and the voltages of 1.8V and 1.2V are read correctly and they stay as long as you will want but when the power is unplugged and plugged back, it goes back to its original behavior and never powers up again until it decides to do so. I don't know what we might be doing wrong. I would be grateful if you can get us some one from IT to assist us. I will send any information that you will need to get us running. I have not worked with the TPS65950 before. I will request a schematic. In the mean time do you have any ideas what to look for? What other information would be useful? Thank you for your help. KES
