The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Measurements >> Other Measurements >> the right power supply equipment for analog chip
https://designers-guide.org/forum/YaBB.pl?num=1141813376

Message started by chu on Mar 8^th, 2006, 2:22am

Title: the right power supply equipment for analog chip
Post by chu on Mar 8^th, 2006, 2:22am

hi all,

i'm choosing a POWER SUPPLY equipment for test and measurement on ANALOG CHIP. please give me some advise on the SPEC, thx in advance.

1) what is the max ripple & noise acceptable for analog chip ? 5mV rms & 3mA rms ? 10mV ptp ? or ?

2) line regulation constant voltage & current ? 0.01% 3mV & 0.2% 2mA ? or ?

3) load regulatin constant voltage & current ? 0.01% 3mV & 0.2% 2mA ? or ?

thank u so much.

Title: Re: the right power supply equipment for analog ch
Post by Paul on Mar 8^th, 2006, 12:23pm

Hi,

without knowing your design it is hard to specify its power supply. Ripple requirements depend on your circuit's PSRR (power supply rejection ratio) and its frequency dependency. Power supply definition also depends on the current consumption of your chip.

Notice that most commercial power supplies are switched power supplies, which usually exhibit ripple at a particular frequency (switching frequency). For low ripple, you should use a low drop-out regulator (LDO) between the switched supply and your chip.

You can certainly find a lot of useful information in the appnotes of commercial LDO vendors (Analog Devices, Linear Technology, Maxim and many others I may forget).

I hope this helps a little

Paul