555 supply current

Thread Starter

quadhed

Joined Jan 13, 2016
48
Does anyone know what the datasheet value of 10-15 mA means exactly? Wouldn't it depend on the supply voltage and resistance of the chip? I know to limit the source current from pin 3 so the chip isn't fried, but what about supply current?
 

Papabravo

Joined Feb 24, 2006
22,082
Does anyone know what the datasheet value of 10-15 mA means exactly? Wouldn't it depend on the supply voltage and resistance of the chip? I know to limit the source current from pin 3 so the chip isn't fried, but what about supply current?
It means that the internal circuitry requires that amount of current for proper operation. Keep in mind that the original version of the chip was implemented in bipolar technology and later versions were implemented in CMOS technology. I would expect a considerable difference in the current consumption of these two versions.

AFAIK there is nothing that you need to do to limit the current consumption of a chip. further, anything that you try will likely impact the ability to function correctly.
 

LowQCab

Joined Nov 6, 2012
5,101
The Bi-Polar-versions generate quite a bit of Switching-Noise
so a Ceramic-Bypass-Cap is highly recommended close to the Chip-Pins.
.
.
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Audioguru again

Joined Oct 21, 2019
6,826
The original old NE555 and LM555 used TTL technology that has a fairly high supply current (even when not loaded). They also produce a "shoot-through" supply current pulse of almost 400mA (!) each time the output switches.
The Cmos 555 ICs dont doo dat.
 

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