Gardarisar My belief is that turning on all 8 outputs at 20 ma exceeds the IC max current. Get on to your supplier and ask them to justify their thoughts. However, driving a LED at 20 mA is often unnecessary today. You should make sure that the design actually tries to 74yctn that.
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A simple indicator LED will be fine at 5 mA. However, driving a LED at 20 mA is often unnecessary today. Sign up using Email and Password. My solution is to use P channel mosfets to switch the power. As is stated in the below table the output max current is 35mA for each output, being the nominal current 20mA, enough to control a LED in every output.
This website has a built-in schematic editor. Maybe you will be OK afterall, or maybe a simple part change can fix everything up. My understanding is that is has a max of 35 mA per pin, but a total of 70 mA for the IC. Home Questions Tags Users Unanswered. Hi, basic schematic added.
You should make sure that the design actually tries to do that. Sign up or log in Sign up using Google. Email Vatasheet, but never shown. Sign up using Facebook. You can edit your question and then click on the icon that looks like a schematic symbol, and it will load the schematic editor.
Glad to know 74hdtn not going nuts. The IC has a global limit of 70 mA. Data sheet is here: Would really appreciate some input. The load is between the IC and dxtasheet source current? I should have added that there are 2 LEDS being driven from each output. My belief is that turning on all 8 outputs at 20 ma exceeds the IC max current. Post as a guest Name. Get on to your supplier and ask them to justify their thoughts.
74HCT573N DATASHEET PDF