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Ah...... ! :-)
OK now, question is, if I have 8 such channels, can I get a nice SOIC for the PMOS? :-)
Seems like a waste of space doing this circuit X 8 out of discreet parts.....
Yes I think current is/was one of the issues (causing voltage to drop).
In your proposed circuit, I would just wire to the emitter of the MOSFET? And why do I need the diode if the "load" is not inductive?
What I had been doing was using a comperator like 393 and connecting the micro output to the (-) and a reference voltage of 2.5v to the (+). The output of the 393 will then be zero when the micro is low an 24v (if that is the supply to the 393) when the micro is high.
Firstly thanks for referring to a great page.
I have used transistors before to rive LEDs etc.
So sorry if this is a totally newbie question, but, in all these circuits (it seems to me) the load is driven by basically connecting the ground (i.e. giving it a path to ground). In this case what I...
I am doing a small box that will simulate some signals which are normally 24v (or 12v). Presently everything is working (i.e. firmware running) and the output is 3.3v TTL (from the micro). But, in order to interface to the equipment being tested, the 3.3v needs to be 24v (or what ever the supply...
I am using another LDO (MIC5209) and have been wanting to test a drop-in replacement. I got two types of LM1117 (LM1117MP-3.3 from National and LD1117S33CTR from ST) and connected them, but both do not work (input voltage is 5v). I tried this again on a breadboard and still they do not work. Is...
Yes, I also increased the bypass cap on the MAX3232 to 10uF and that helped, but when you connect a RS232 device the problem increases. I want to try the series resistor thing but have to make a new PCB for that... but few people have suggested that also (10ohm with 10uF on either side).
On my board most of the components are 3.3v and there is one (important one) that is 5v.
Presently I am using a power section that has a 5v switcher and then a 3.3v LDO.
Now I need to add a 3.8v section (to accommodate a GSM module). But I don't want to use two switchers.
So, what I am thinking...
I replaced the 0.1uF bypass cap with a 10uF one and it did help bring the noise down to a 10-15mV level. But, when the line is driving, this increases again by X2 or X3.
I was wondering, how about if I use a separate LDO only for the rail that goes to the RF module? Would that solve/help the...
It is a 2.4GHz module, based on Nordic nRF24L01+
Quoting from one of their documents: "If these spikes reach the power pins of the RF part of the circuitry, serious malfunction might result. It is therefore mandatory to keep separate power lines to the analog and the digital domains of the...
Well that is the issue. It does not affect the digital components, but it messes up a RF module which is fed from the same Vcc. That is the reason why I want to suppress it. Here is an image of Vcc at present:
Actually as I read about this, it seems that beads are only good for MHz range isolation. My noise is in the XXKhz range, so how can this work? Or am I not understanding something?
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