# Tag Info

### How to calculate components values for LM3421 in SEPIC mode

I find it best to look for relevant app-notes if I'm doing something a little new to me! TI and Linear Tech have some good information on SEPIC and CUK converter design. https://www.ti.com/lit/an/...
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### DC-DC converter fault output

the only change is the PCB assembly house ... the assembly house just bought the ICS and solder them into the board I have just checked the EM2130L02QI IC and seen that it's obsolete since January ...
• 16.4k

### Should I use a DC-DC converter or an LDO?

Consider using a boost converter chip in a SEPIC configuration. This can act as step up and step down in one circuit.
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1 vote

### Should I use a DC-DC converter or an LDO?

It looks like LiPo batteries stay above 3.3V in normal charge levels, and drop to 3.0V when they're below ~80% capacity. Image source: https://learn.adafruit.com/li-ion-and-lipoly-batteries/voltages ...
• 11
1 vote
Accepted

### Power supply design requirements for IGBT driver

For drive supply requirements I go by the highschool physics approach: $Q=CV$ and $I=dQ/dt = f_{pwm}*Q$ (note that dQ is the difference in charge to create the gate leading edge, the trailing edge ...
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1 vote

### How can I measure the output of a voltage booster circuit?

The LED will clamp the boost output voltage to its forward voltage. That is, if your LED is a blue or white type, the max voltage will be clamped to about 3 - 3.5V, peak. The challenge with using a ...
• 40.2k
Accepted

### How can I measure the output of a voltage booster circuit?

how to use a multimeter to measure the the total output voltage If by "total output voltage" you meant the peak value of the pulses, you could do something like this: The diode must be a ...
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### How can I measure the output of a voltage booster circuit?

An oscilloscope would be your best bet. If you don't have an oscilloscope, connect a capacitor in parallel with the LEDs. From the junction of the LED and the inductor to ground. That will get you a ...
• 57.4k
1 vote

### RLD + RC Snubber for MOSFET

Forget about the snubbers for a moment and focus on the initial design and basics. First of all, I kindly advise you to get rid of 2110 and use a gate transformer instead. Or, if you really want to ...
• 16.4k

### Connecting the grounds on a non-isolated DC/DC converter

Your illustration show that -VIN and -VOUT are the same grounds. So it's theoretically the same potential to both side. I.e. it's a wire. You can ground both side to improve output decoupling and ...
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### The source part of an IRF540N transistor

Your inductor value is way too small. It looks like it’s actually 0.1uH (third band is gold, not brown) instead of your intended value. More here: https://www.rfcafe.com/references/electrical/inductor-...
• 40.2k
1 vote

### DC-DC booster functionality

The inductor alternately stores energy as magnetic flux, and releases energy as current. transistor on: ‘charging’ L1 (building flux) transistor off: ‘discharging’ L1 (collapsing flux) During that ...
• 40.2k

### DC-DC booster functionality

Q1 turns on, connecting the end of L1 to GND. D1 is off, and so load current is (temporarily) supplied by C2. Current builds up in L1, and when Q1 switches off, L1 'wants' to keep the current flowing -...
• 12.4k
Accepted

### Inverting DC-DC converter input ripple issue

What is providing the 3.3V source? I'm suspicious you are triggering a constant current limit in that supply. So when the -3V3 is operating it is drawing just a little too much current on the +3V3, ...
• 190
1 vote
Accepted

### Improve current limit on boost converter

Following the advice here, I experimented with adjusting the frequency and inductance values and found that I could squeeze slightly more current out with optimized values. In addition, by taking the ...
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### If we change the PV panel, should we also change the MPPT controller block?

If your MPPT controller can control the load so it matches the rise in PV output impedance when shaded then your energy conversion will be optimal. This demands you regulate PV voltage with solar ...

### If we change the PV panel, should we also change the MPPT controller block?

A lot of MPPT controllers have a voltage/current range where they perform optimally and a much wider range where they perform "somewhat". You may be operating in this wider range when the ...
• 5,253
1 vote

### DC-DC buck converter duty cycle issue

A: Non-standard analog requirements for signal conversion with unusually high input voltage wasted are unpopular for mass production targets. But easy to design with a Quad Op Amp and a 24V LDO ...
1 vote

### DC-DC buck converter duty cycle issue

"Shopping questions are off-topic", but there does exist a class of devices that are mid-voltage, low-dropout-compatible, frequency-adjustable DC-DC buck converters. Refer to several of the ...
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### When is it allowed to use non-isolated PoE?

Practical Guidelines to Designing an EMI Compliant PoE Powered Device with Non-Isolated DC/DC https://www.ti.com/lit/an/slua454/slua454.pdf The circuit uses the TPS23750 in a non-isolated buck ...
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Accepted

### Why did the CS resistor explode in this circuit?

The inrush current through T1 and D1 to charge C6 will cause T1 to saturate. If the converter tries to start with the saturated inductor, it's essentially a short and large current will flow into the ...
• 19.5k
1 vote
Accepted

### What causes spikes on a primary push-pull transformer with good snubber and tvs?

I continued my measurements and also found voltage peaks on the other leg. They do not appear at the same time. Finally, I decided to try to reduce the slew rate at the gate off command by removing ...
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### Is this op amp circuit a promising idea to measure 300VAC?

Absent the question of proper circuit protection, that should work except that you seem to be designing for 300V peak. 300VAC generally means 300V RMS; that, in turn, means about 425V peak -- your ...
• 35.8k
Accepted

### Is this op amp circuit a promising idea to measure 300VAC?

Re. Circuit #1 The op-amp is incorrectly biased. Re. Circuit #2 Add a fuse! Assume that the rest of the circuit can fail shorted. Accommodate the +10% high line condition by increasing the V-I ...
1 vote
Accepted

### Soldering wires to non-plated pins?

There were a lot of helpful tips in the answers/comments, but unfortunately they made no difference. I tried a moderately hot iron (650F once and 750F once) with a wedge/chisel tip. I used a thick, 1....
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