ejiblabahaba

9 ms·

31.
by ejiblabahaba 3y ago
For output voltages that must be higher or lower than the input, there are other topologies like buck-boost, Ćuk, or SEPIC. In general, DC-DC converters can change their pulse duty cycle to modify the amount of energy transferred per switch
32.
by ejiblabahaba 3y ago
TI pretty clearly distinguishes between LDOs and other categories of linear regulators on the basis of using a FET pass element (which is true of neither the LM317 or the LM7800 series, both are Darlington-based). See section 2: https:&#x2
33.
by ejiblabahaba 3y ago
TPS7A20 is 6.5uA, $0.10/ku. TPS7A05 is 1uA, $0.19/ku. It's not that hard to do better than 400uA! And if you don't mind coughing up when it counts... TPS7A02 is 25nA, $0.45/ku. Triple the price, but more than four o
34.
by ejiblabahaba 3y ago
Sure. TPT-PV systems are pretty close to the same concept, with a bigger LCL filter on the output. IMO the tricky part is all the compensation and software design required to minimize ground leakage currents, since that needs real-time anal
35.
by ejiblabahaba 3y ago
Maybe TPS61094 or something similar? https://www.ti.com/lit/ds/symlink/tps61094.pdf
36.
by ejiblabahaba 3y ago
As you get close to 5% duty cycle you start having tough problems keeping the control loop stable. You might have better luck stepping down 48V to 12V and 12V to 5V cascaded. Less efficient, but cheaper than blowing up your supplies regular
37.
by ejiblabahaba 3y ago
During a college internship, I actually debugged an EEPROM corruption issue on a PLC card all the way back to the power supply the original designer had copy-pasted out of the datasheet. The compensation network they had used was definitely
38.
by ejiblabahaba 3y ago
There's not much to it. There's usually some stage-1 converters at a subnetwork of panels that step the panel voltage up to a common DC bus voltage with all the MPPT and relevant OTP/OVP/UVP/OCP/etc. Then the b
39.
by ejiblabahaba 3y ago
Technically all DC-DC converters at a minimum have an AC current in their input and output capacitances. Since we see a small ripple voltage across the capacitors, it must be true that the direction of the current flowing in the capacitors
40.
by ejiblabahaba 3y ago
Nowadays you can pretty easily find switchers with sub-100nA quiescent current + leakage, e.g. TPS62840 (of course, that's assuming you're at room temperature... FETs at high temperature are all crap for leakage). I note you get 8
41.
by ejiblabahaba 3y ago
You can use this observation to build a "buck-boost" topology that can make the output voltage larger or smaller than the input voltage. This is common for 1sNp Li-ion batteries that need a high-current 3.3V rail - buck from 4.2V
42.
by ejiblabahaba 3y ago
In principle yes, in practice it's rarely worth the cost and complexity. If you're careful about the converter design (keep the high-current loops extremely short, use counter-rotating loops to tightly confine magnetic field withi
43.
by ejiblabahaba 3y ago
Step 1: You briefly short the inductor. Inductors cannot instantaneously change current, so they will linearly ramp up the current over time. This builds up a magnetic field in the inductor. Step 2: Stop shorting the inductor. Inductors can
44.
by ejiblabahaba 3y ago
A few points: 1) LM317 and LM7805 are not LDOs. LM317 is a series regulator, which is way more flexible and has some infrequent but difficult-to-emulate use cases. LM7805 is a linear regulator but has substantial voltage drop relative to a
45.
by ejiblabahaba 3y ago
This is absolutely something you could do, in the sense that no one in electrical engineering will raise an eyebrow if you call your DC-DC conversion with an "AC" step in the middle a DC-DC converter. There's fundamentally go
46.
by ejiblabahaba 3y ago
Based on Google's specs[0], the GMF5Z battery in the Pixel 7 pro is 18.96 Wh and 65 g, which is around 292 Wh/kg. [0] https://support.google.com/product-documentation/answer/9682...
47.
by ejiblabahaba 4y ago
I found this to be a pretty expansive answer to this question: https://chipsandcheese.com/2021/07/13/arm-or-x86-isa-doesnt-...
48.
by ejiblabahaba 4y ago
Aside from the much-touted uses in cryptography, probably the biggest use will be as universal quantum simulators. A lot of quantum simulations are infeasible beyond trivial interactions, because the classical memory and number of computati
49.
by ejiblabahaba 4y ago
I think it's possible to be proud of your children for adapting to modern interfaces more quickly and easily than you, while simultaneously remaining cautious about risks those technologies can present. I don't think the straw-par
50.
by ejiblabahaba 4y ago
On the contrary: where humans are directly involved in the processes of aviation, we're stuck with process control most of the time, and it's clearly insufficient against motivated malfeasance. When an airplane crashes due to a de
51.
by ejiblabahaba 4y ago
I've yet to meet a human being that came with an operator's manual, a maintenance manual, schematics, engineering diagrams, a diagnostic and logging system designed to survive catastrophic system failure, or a multi-billion dollar
52.
by ejiblabahaba 5y ago
Sometimes it's to handle higher currents, other times it's to reduce the bond wire inductance and improve the high-frequency response. For power pins it can be both. Especially for a multi-chip module with some digital circuitry,