Apr 16, 2007 #1 G gdhp Advanced Member level 4 Joined Jan 7, 2005 Messages 116 Helped 2 Reputation 4 Reaction score 1 Trophy points 1,298 Activity points 931 HI all I have a puzzle about the PSRR frequency range. For normal analog block, such as OPAMP, BG, when we consider its psrr, how is the power ripple frequency range is considered. 1K is enough? I thought on the chip( and also board), a big cap is between the power and ground. So only very low frequency ripple on power supply should be considered. Is it ok? What is the maximun frequency should be considered? Thanks! gdhp
HI all I have a puzzle about the PSRR frequency range. For normal analog block, such as OPAMP, BG, when we consider its psrr, how is the power ripple frequency range is considered. 1K is enough? I thought on the chip( and also board), a big cap is between the power and ground. So only very low frequency ripple on power supply should be considered. Is it ok? What is the maximun frequency should be considered? Thanks! gdhp
Apr 17, 2007 #2 W waxtomato Member level 5 Joined Sep 1, 2004 Messages 86 Helped 13 Reputation 26 Reaction score 5 Trophy points 1,288 Activity points 354 Actually, the on chip CAP is normally not enough. People often apply 0.1u ~ 10u cap on PCB board . I often get power noise > 20kHz when I test
Actually, the on chip CAP is normally not enough. People often apply 0.1u ~ 10u cap on PCB board . I often get power noise > 20kHz when I test
Apr 17, 2007 #3 G gdhp Advanced Member level 4 Joined Jan 7, 2005 Messages 116 Helped 2 Reputation 4 Reaction score 1 Trophy points 1,298 Activity points 931 waxtomato So you mean that when i consider the psrr frequency range of chip, the frequency should between 0-20k?
waxtomato So you mean that when i consider the psrr frequency range of chip, the frequency should between 0-20k?
Apr 17, 2007 #4 S strennor Advanced Member level 4 Joined Dec 9, 2003 Messages 104 Helped 18 Reputation 36 Reaction score 3 Trophy points 1,298 Activity points 488 Hi, Are you designing audio chips? The datasheet only has spec of 1k, but has PSRR figures upto 20k. I think you should think about it based on your application.
Hi, Are you designing audio chips? The datasheet only has spec of 1k, but has PSRR figures upto 20k. I think you should think about it based on your application.