1NA datasheet, 1NA pdf, 1NA data sheet, datasheet, data sheet, pdf, BKC International Electronics, V, 1 W silicon zener diode. 1NA. 1NA. 1NA. 1NA. . This datasheet contains the design specifications for product develop- ment. Buy MULTICOMP 1NA online at Newark element 1NA – Zener Single Diode, V, 1 W, DO, Technical Datasheet: 1NA Datasheet.
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If you want decent accuracy throw the zeners away and use some low dropout 3. Can I still get a reliable voltage if Vcc dips below 5V? Typically the dynamic resistance of the 1NA is about 5 ohms, so you could approximate it with an ideal 3. This query was simply to highlight my dismay at how poor these zeners really are!
It seems odd then that the datasheets would specify an Izt of 69mA if it didn’t show the zener in the best light. What’s odd is that the BZX55C is showing more-or-less the same behaviour although with different resistors. At least at no load or very small load the LDO regulator will be way more efficient. Even if it specified at 70mA, there is going to be some there and in this case it is not negligible therefore it must be incorporated in to your circuit model, that why your circuit analysis provides a different answer but adding the zener resistance to the model gives a solution that approaches more closely your result.
Buck8pe 8 Indeed it would seem to be a much easier solution to just get an adjustable LDO, if this thing is meant to be used as regulated supply voltage. I suppose the point is, at 70mA, according to the datasheet, the voltage across the zener should be 3. Rather than use rules of 1n4279a which you may or may not understand, you should first look at the data sheet of the part you’re using.
Double check this supply.
(PDF) 1N4729A Datasheet download
I see your edited? There are a couple of issues here. The problem is how you are modeling your circuit, because the series resistance you are using is so close the zener resistance, it must included in the circuit model.
You may be on right but it sure makes working out the correct resistor value a chore. You do not see 3. Sign up or log in Sign up using Google. I suspect that 1n4729s you retest the “1N” parts with a test current of something like 20mA 70 ohms you may find that they’re within spec voltage-wise. I’m not sure what the temperature coefficient is for this device and the data sheets are lacking in that respect.
The ones with voltage of 5. As shown in 1n4729w circuit below which models the behavior that you are seeing of a voltage reading of about 4V from the zener diode. The dynamic resistance describes the small-signal behavior near the test current. It’s incorrect to add a voltage at the test current because of the dynamic resistance.
Kvegaoro 2, 11 What 14n729a volta de you require? Both Zeners came from separate suppliers. Sign up using Email and Password. Does this conflict with what Kvegaoro is saying?
You don’t say what you saw there.
Renesas – datasheet pdf
For low voltage shunt regulation either use a series regulator LDO or a device such as the TL which has a band gap reference, and an opamp in a 3-poin package to create an almost perfect “Zener diode”.
If you include the dynamic resistance in the model, you must use a lower voltage for the ideal zener. The next problem is that at 70mA and 4 volts, the power is 0. Can you expand on the statement: The dynamic resistance of the Zener may not be able to drop low enough, even with 70mA available to it, to make the proper resistor divider equivalent for the node to be equal to 3. Email Required, but never shown.
I wanted to confirm that I wasn’t doing anything stupid.
Actually, as it happens I had reached the same conclusion. First this stated in the question: Since you are driving more than 10 times that amount of current through it, it is no wonder that your voltage is high.
As shown in the circuit below which models the behavior that you are seeing of a voltage reading of about 4V from the zener diode simulate this circuit — Schematic created using CircuitLab.
See Fig 2 in diodes.
Home Questions Tags Users Unanswered. Actually, it was a candidate for a regulated supply fed by a CCS. Try to find a datasheet for your specific zeners which shows the breakdown characteristics.
If you want to get 3. If you increase the resistor the voltage across the zener should go down. Zeners are notoriously power inefficient even at no load. It’s like 1n479a Zener resistance isn’t decreasing as the current increases, which is not what I’d expect.
Is that the dynamic resistance of the zener? Zeners with nominal voltages less than 5V or so have very soft ‘knees’ poor regulation and are not really that useful as usually better alternative are available. Because it rises as per the quote you must have an unstable power source of 5V and this is rising as you increase the load resistance.