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# Over Temperature

182 Threads found on edaboard.com: Over Temperature

## Noise Floor vs. Noise temperature

I haven't gone over your calculation so I will not comment on them but I would like to point out that the signal to noise ration for a modulated signal can be very much lower than the decoded signal to noise ration. So in many cases you only need your signal to be a few dB over the noise floor to get a perfect demodulated signal. When calculating l

## How to stable the PLL over wide temperature range(-40~85℃)

I want to design a PLL operating over wide temperature range:-40~85℃. The key is to design the VCO operating over wide temperature range:-40~85℃. I used a TCXO for VCO reference frequency. Then how to make sure VCO is operating over wide temperature range:-40~85℃. (...)

## Wide temperature range voltage reference design

Hi, I don't know where to post this, it's not DIY, but I'm not an IC designer, 'though I am happy with this design idea, an idea that I think could be enormously improved and simplified by some-one who knows what they're doing. I've been trying to design a simple flexible voltage reference that is stable over -50 to 150?C, and although this i

## ERNI connector current rating at 100degC?

Page 5 of this 5-way ERNI connector datasheet (as attached) says that it can carry 17 Amps (Total) at 100degC. However, the temperature derating graph (attached below) for this same connector suggests it can only carry 11.04 Amps over all 5 connector blades at 100degC?which is correct?....11.04 Amps, or 17 Amps?

## Can a latch be used as a flop by modifying its enable input?

Can you tell us what the minimum guaranteed clock pulse width will be over all corners of Process,Voltage and temperature for any layout? If you cannot then you shouldn't try to build your own delay lines. John Eaton

Klaus raises a good point. While discretes such as electrolitics as mentioned by c_mitra will have a time/temperature graph associated with them - IC's don't really need that. (The issue with electrolitics is simple drying out of wet electrolite over time) As Klaus says ESD does damage chips over time and the damage when seen under a (...)

## Safe low temperature heating element

Hi, "over room temperature" is difficult, because it depends on room temperature. Absolute temperature, lets say 50°C is easier, there are thermo switches. *** you could also use PTC or NTC devices in the transistor dirving circuit to protect against overheat. *** The most "advanced" way is to measure (...)

## Detection of wireless cmmunication parameter using Labview

I never played with UDP but it should be simple: 1. On the remote module you create the packet of data for sending over UDP. Each variable should go into some fixed place in the packet (for example temperature - bytes 10..18, time - bytes 19..27. etc.) 2. Send the packets from the module by using UDP. Assign some address and port 3. On the PC sid

## LM2576-5.0V Power Supply Problem.

The IC is dissipating 7V X 2A = 14W, it needs a heatsink. The IC might be OK it just closed it self down on thermal over temperature. Frank

## The gain of Track-and-Hold circuit

You should either - compensate the gain loss somewhere in the whole analog chain by amplifying the signal with an appropriate gain>1 not ideal, as your source follower buffer's gain may be not constant over signal voltage and temperature. A correction at the digital output would need a microprocessor action. or - change your buffer

## What is the lowest possible value that Vgs(th) can be for any BSS123 FET?

Adding the typical Vgs,th temperature coefficient shown in Fig. 4 to the 25 °C Vgs,th range of 0.8 to 2 V sounds reasonable, but strictly spoken, there's no specification of worst case Vgs,th over the full temperature range in the datasheet.

## High side current monitor (INA193) solution?

The datasheet suggests the error should be much smaller than you describe over the full temperature range. Can you post your detailed measurements of Vout vs Is at different temperatures? How are you measuring Is and Vout during the test?

## Cooling fans inside totally enclosed SMPS enclosure?

Enclosed cases are always critical thermal designs. Apart from having to use a large fan to ensure equal distribution of air flow through the greatest possible internal surface of the cabinet, it may also be necessary an additional small fan over the hottest components in order to prevent the junction temperature exceeds the specified limit.

## STM32F103 and RS-485 on internal HSI?

Is a good idea use STM32F103 only with internal HSI oscilator if this device communicate over RS-485 (38400bps) and work in temperature (-10 ~ +50 C)? Datasheet say accuracy HSI is TA = ?10 to 85 °C ?1.5 - 2.2%. HSI is User-trimmed with the RCC_CR register , but the trimming step is about 40kHz (0.5%/step) and thus do not even know whether it

## Linear Voltage regulator with 1% or better accuracy over inustrial temperature range

I'm looking for a linear voltage regulator 0.5A output @ 5.0Vdc, accuracy needs to be +/-1% or better over entire industrial temperature range. Input voltage will be between 12 and 24Vdc. Prefer the simplicity of a 7805 style regulator, with better accuracy. Does such a component exist, and if so part #? And if not, circuit suggestions for im

## Rate of Temperature rise of heatsink

Won't the Mosfet die early due to "thermal fatigue"? It heats and part of it expands then it cools and contracts. over and over until something (a bonding wire inside?) breaks. If you keep it from getting very hot then it will last MUCH longer.

## Choosing crystal for RX circuit

YOu can't make an Xtal 20 ppm over a wide temperature range due to the 3rd order variations with different cuts. You can get a 25ppm tolerance at room temp and a 25 ppm over a wide temp range and design a compensation and null offset circuit. But no need now. For about \$2~4 now you can get a 0.5 to 10ppm TCXO which is (...)

## AMWEI Thermistor- PTC & NTC thermistors temperature sensor manufacturer

AMWEI Thermistor, professional manufacturer of PTC & NTC thermistors (THERMally sensitive resistors) and thermistor temperature sensors probe. PTC thermistors application cover over-current & overload protection, telecom, lighting switching, motor starting, temperature sensing & protection, self-regulation (...)

## Advantages of Embedded Linux Over Bare Metal PIC Code

I am not sure what embedded Linux does for us which we cannot do with bare metal code. I want to see Embedded Linux in action. Is there some website that contains basic projects which demonstrate Embedded Linux in action and I can look at the code and learn as well?

## Pros & cons of fixed resistor variable VDC bench supply/Op Amp voltage followers?

An op amp plus a power transistor can certainly be used for a bench supply but IC linear regulators, like the common LM317, are simpler to use and typically have a built-in voltage reference, current limit, and over-temperature protection, so that would be my first choice. The LM317 can have a continuously adjustable voltage output using a pot,

## How to detect Over temprature and / or Open Load in Solenoid Driver BTS716G

Hi, As shown in attachment we are using BTS716G for Solenoid driver. In our design there are 16 solenoid. The block attached here shows driver for 4 solenoid, other block are ideal to this. 116525 Now our question is how we can detect the Open load error or over temperature error from a single signal for two channels

## Negative Feedback Circuit Design

Some lasers come with a built-in PIN diode that should be used in the negative-feedback circuit to keep laser current constant over temperature. Laser driver should be designed to keep the current within limits, and feedback from the PIN photodiode and temperature sensor is used to keep light output stable.

## temperatue calibration in heater thermostat

If the other components in your system produce so much heat I think it will be very complex, if not impossible, to calibrate the software to compensate for this. The measured temperature is not only a function of the environment temperature but also air flow over the triacs, direction of the airflow, thermal isolation (i.e. dust) and (...)

## Trying to find Diode

Knowing no electrical schematic makes it difficult to decide. temperature over 100 C to generate steam. I would try to put a 1N4001 diode in place of the removed one an give it a try run. Instead of the complete circuit I would use a bimetal thermostat switch from a discarded iron to keep the heater

## Why H-bridge should be set to off-state (high-impedance) in a fault case?

I read a thesis on H-bridge design which said : All four power transistors are switched into off-state because of a fault (short circuit, under-voltage, over-temperature). Similiar opinion can be found in another book: Smart Power ICs - Technologies and Applications (By B. Murari, F.Bertoti, G.A. Vignola) Why all the

## Elementary Q: Regarding Feedback Cct

If you do not have negative feedback then the temperature is not controlled. Instead you could detect over-temperature then have something turn off the power until it cooled to a low temperature then something turns on the power again. But then the temperature jumps up and down. The triangle is an amplifier (...)

## Upper limit of carrier frequency for PWM

you're reliability guru's scare easily. SiC is very reliable because it has such low losses and junction temperature easily over 200C. i said EASILY. i built a 50kW inverter with SiC at 600V and hit 98% efficiency over entire range. that was like 7 years ago or so. i also met MIL-STD 704 & 160 for noise. this competition has no (...)

## Pure Sine Wave Inverter Protection

The general protections required are 1. over Load and Short circuit 2. Battery / DC input Low 3. Battery / DC input High 4. over temperature 5. Closed feedback loop Hope it helps you Thank you JTRao

## Preventing connectors from corroding with silicone?

Depending on the number of adjacent pins carrying the same current, temperature rise will certainly exceed the allowed 30'C for 1 pin at rated current. The plating is only 0.914μm tin over Phosphor Bronze, making it an easy target for rapid loss of plating if wet contact , or "hot insertion" is performed. Could be a poor choice. How often is

## Problems with ceramic capacitors run at near their rated voltage?

Normally the capacitance will be specified over the temperature range, and lowest in the extremes.

## MCP73831 output reading issue / regulator heat

That heat sink is 24.4 degs C per watt, you are dissipating 2.5w,so the heat sink will rise to 24.4 X 2.5 over the air temperature = 60 degrees C. If the air temperature is 20 degs C, then the heat sink will run at 80 degs C = VERY hot. Frank

## Time in rtc being slow....

the DS1307 will drift over time in particular with temperature variations - have a look at there are temperature compensated RTCs, e.g. the DS3231 even then if the system is connected to the internet I wo

## Over charging protection circuit

I am making an over charging protection circuit for a 12V, 30Amps battery. I am confused that when charger will be removed, will the battery voltage remain at same potential as the potential with charger? E.g when charger is connected voltage measured is 14.2V, when the charger will be removed, battery voltage will be 14.2 or less than 14.2?

## Gain changes in Low Voltage Amplifier over the time

I built up simple inverting-Amplifier with LM358 which Gain is R2/R1 = 26. input voltage is 20mV fixed and hence output voltage should be approximately 520mV. the problem is that the output voltage changes over time while the temperature(25°C) and other circumstances are stable. for instance, if output is 520mV today, next week it changes to 530mV

## Negative Temperature Coefficient

Do you care how much error there is? Have you tried to calculate Sensitivity Analysis? ( partial derivative of equation) Then determine max error due to difference in R25 and B over your specified operating temperature range? Then see what other changes are needed with fixed resistors are necessary?

## Help! LM2903 Hysteresis varies over temperature

Hi, I am trying to create small current detect circuit using LM2903 (comparator). Objective is to detect if current is lower than 4 uA. (Range of I1 is 0uA to 1800 uA) R4 is there to build up the Voltage which is input(+) to comparator. R1 and R5 are voltage divider to give Vref (equivalent to 4 to 5 uA). The circuit is working fine during simul

## Oven-controlled-voltage-controlled Crystal Oscillator

First please tell us what you need. Your questions indicate you do not know. Quartz crystal oscillators are made in the varieties you named. For a better stability over temperature they are ovenized and heated at 50 - 60 deg.C by a thermostat so they do not vary the frequency due to ambient temperature. If a fine tuning is needed a (...)

## switching mode power amplifier transistor

The only control over what it can stand, is temperature and service-factor. To make it stand more, you'd work on making it less dissipative (on resistance, sharp gate drive edges to minimize time in lossy regions). But a RF PA designed for low cost will use as crappy a process as you can get away with, forcing a poorer trade there). Your load imp

## aluminium capacitor tolerances over temperature/time

Hi, I am using Panasonic made aluminum capacitor and looking for the information for capacitor tolerance over temperature and aging. Any one have any idea how to consider it for 22uF, 20% capacitor? Any help would be highly appreciated. Regards, Umesh

## FPGA performance testing application

Performance is specified over a range of temperatures and the tools are designed to place components in paths that will meet these specifications over that temperature range. Once you have a design, you cannot make changes and compare the new results to old ones -- the critical path may be different in each case. You would (...)

## switching powe supply life time??!!

Switching inverters can last a long time depending on the quality and built of the design. One example: Enphase Energy makes a 250W solar panel inverter guaranteed for over 20 years operating in an ambient temperature of up to 65°C.

## Voltage Reference Measurement

1. A well designed breadboard should do. 2. As its a voltage reference, its output should be stable over a wide temperature range, so you need an oven and a refrigerator. its is unlikely that a multimeter will provide enough descrimination to measure the output drift, i.e. You should be able to measure the output voltage to better then 1mV. 3.

## why we don't bias BJT by a battery connected B and E?

Usually, you'll also want a signal voltage to be fed to the base, at least if the transistor is working as an amplifier. Furthermore, Vbe bias must be varied over temperature. Finally, who replaces all the batteries?

## Noise figure variation in a device with frequency!!

How the Thermal Noise remains constant over a temperature range ?? It's should be increased by temperature. NF is generally increased by frequency,it's normal and expected.( Except some GaAs devices at lower frequencies because of flicker noise)

You can use several things to sense overload of transformer. One sensor can be Hall current sensor, which will detect current on maximum and overcurrent. Second thing can be measuring temperature on maximum allowed and over that. But first you should have transformer specification.

## designing switch mode mobile battery charger

i want to make a switch mode battery charger for li-ion battery of mobile.i need a circuit diagram and i want to use microcontroller to stop the charging automatically after some time and to stop charging if over temperature occurs You can use cheap dedicated chip for this purpose MCP73832. Complete circuit requir

## Over voltage on an electrolytic capacitor

What happens to them if their voltage limit is exceeded by a small amount over a period of time? Do they buldge as they do when you apply a reverse voltage? Marked voltage rating on capacitor body is maximum safe voltage, capacitor can handle voltage over that but that is specified in manufacturers datasheet

## voltage insensitive to temperature

First of all you must test the circuit to see what its doing over the temperature range. The reason for changes are likely to be the change in Vbe of the transistors first then the values of the resistors changing, second. Depending on what is required one form of compensation would be to put a forward biassed diode in series with R8, so as the

## SPI Master setup for PIC12 series

I have some assembly code that I wrote a while ago for a PIC16F628A. It is a temperature logger than interfaces to an RTC and a temperature sensor over I2C. It has been at least 5 years since I have even read this code and I don't remember a lot of it. However, I was able to locate it and put it up as a gist. It isn't incredibly well (...)

## threshold voltage variation wrt temperature in MOS

Basically, temperature increase mobility of electrons and holes . hence now there are plenty of electrons and holes and the conduction requires less voltage. Hence Increase Temp-> Decreases Vt. For the above statements,can you give the formulas so that we can have some discussion over here. Give some theoretical proof for the above Here!!