Does it matter which power rail comes up first? I have been reading about certain types of op amps need the negative rail on first.
What if there is an input signal before power-up?
Dual supply operational amplifiers such as the TLE2064 intend to have the supplies brought up at the same time. Although many operational amplifiers will tolerate one supply being brought up before the other you can't always be certain just any amplifier will be tolerant of that practice, or that will be the case over years of a particular amplfier's production life. Semiconductor processes evolve over time and a characteristic such as power supply cycling tolerance can change.
A problem that can arise from bringing one supply up before the other is the possibility of latch conditions. Many integrated circuit technologies require reverse-biased junctions to maintain isolation between individual semiconductor devices on an integrated circuit. When only one supply is applied improper internal biasing may prevent the device -to-device isolation from development and unexpected semiconductor structures such as 4-layer devices (SCRs) can form. Once an SCR latches current can flow can be unpredictable and could result in malfunction, or even damage to the device.
It is best practice to bring the two supplies as close in time as possible.
PA - Linear Applcations Engineering
So are you saying the TLE2064 will have a problem with a rail powering up before the other?
No, the TLE2064 may handle it just fine. But we do not characterize, test, or assure any particular behavior for the device with one supply's start-up delayed relative to the other.
PA - Linear Applications Engineering
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.