555 not oscillating at right frequency. (Gets hot on circuit board)

Thread Starter

quadhed

Joined Jan 13, 2016
23
Hello. I've designed my circuit using Tina. It works in Tina. I've made PCBs from the schematic, but when I slap it together it makes the 555 hot. The duty cycle is less than 50%. I have no idea why the pcb is making the 555 hot. NextPCB made it. The solder joints are solid. What could be making the 555 so hot? Many thanks.
 

dl324

Joined Mar 30, 2015
13,506
I've designed my circuit using Tina. It works in Tina.
Circuit simulators are infamous for not telling you about important things (like exceeding component specs).
I've made PCBs from the schematic, but when I slap it together it makes the 555 hot.
Did you breadboard before having boards made? Simulators aren't always right and you can save yourself some grief by taking that necessary step.
I have no idea why the pcb is making the 555 hot.
It isn't the PCB. It's something about your design (supply voltage and/or output loading). Post a schematic and pictures of the PCB.
 

MrSalts

Joined Apr 2, 2020
712
Hello. I've designed my circuit using Tina. It works in Tina. I've made PCBs from the schematic, but when I slap it together it makes the 555 hot. The duty cycle is less than 50%. I have no idea why the pcb is making the 555 hot. NextPCB made it. The solder joints are solid. What could be making the 555 so hot? Many thanks.
Did you breadboard your circuit before designing your PCB? Did the 555 get hot when you breadboarded it?
 

MrSalts

Joined Apr 2, 2020
712
S.C.H.E.M.A.T.I.C - ???
Give the OP some time to answer before "yelling" with capital letters and periods. If you are yelling because you frantically need to solve a problem, look to some other forums - there are plenty of problems to solve for everyone.
 

AnalogKid

Joined Aug 1, 2013
9,480
Yeah, got a bit carried away; but only a bit. Someone with enough experience to create a schematic in an electronic format and port it to a pc board layout has to know the critical value of a schematic in resolving a component-level question. Paraphrasing Rear Admiral Joshua Painter,

"Engineers don't take a dump, son, without a schematic."


ak
 
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