Ultra Thin 10K Thermistor (4890) chip
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- henryc_mit
- Posts: 2
- Joined: Wed Jan 25, 2023 12:13 pm
Ultra Thin 10K Thermistor (4890) chip
Hi, I was wondering if we could be given more information about the actual chip that is inside the thermistor, like the product number or company that makes the actual chip. Thanks!
- adafruit_support_mike
- Posts: 67454
- Joined: Thu Feb 11, 2010 2:51 pm
Re: Ultra Thin 10K Thermistor (4890) chip
There is no chip. A thermistor is a resistor with a large thermal coefficient.
All resistors change value in response to heat. There are some alloys like Constantan and BANNED that change very little, but they do change. Typical resistors vary from 30ppm to 300ppm per degree C.
In most cases the resistance gets lower as the temperature increases, so we say the resistors have a negative temperature coefficient. In some alloys the resitance increases with temperature though, and we say those have a positive tempco.
Thermistors are made from alloys whose value changes dramatically with temperature.. usually 1000ppm (0.1%) per degree C or more. There are thermistors with both positive and negative tempco.
All resistors change value in response to heat. There are some alloys like Constantan and BANNED that change very little, but they do change. Typical resistors vary from 30ppm to 300ppm per degree C.
In most cases the resistance gets lower as the temperature increases, so we say the resistors have a negative temperature coefficient. In some alloys the resitance increases with temperature though, and we say those have a positive tempco.
Thermistors are made from alloys whose value changes dramatically with temperature.. usually 1000ppm (0.1%) per degree C or more. There are thermistors with both positive and negative tempco.
- henryc_mit
- Posts: 2
- Joined: Wed Jan 25, 2023 12:13 pm
Re: Ultra Thin 10K Thermistor (4890) chip
Sorry, when I said chip, I meant the actual part. I didn't mean to imply that it was a discrete IC.
I am just wondering where I could source a bare SMD thermistor (not already encased in something) that has the same physical layout as the thermistor shown in product 4890. Mainly that the landing pads are on the longer side of the SMD component, and not the shorter sides.
I am just wondering where I could source a bare SMD thermistor (not already encased in something) that has the same physical layout as the thermistor shown in product 4890. Mainly that the landing pads are on the longer side of the SMD component, and not the shorter sides.
- adafruit_support_mike
- Posts: 67454
- Joined: Thu Feb 11, 2010 2:51 pm
Re: Ultra Thin 10K Thermistor (4890) chip
I doubt the thermistor element is a separate device. The whole thing is probably made as a piece.
You can get thermistors from Digikey easily enough:
https://www.digikey.com/en/products/fil ... PYpAF0BfIA - NTC thermistors
https://www.digikey.com/en/products/fil ... PYpAF0BfIA - PTC thermistors
You can get thermistors from Digikey easily enough:
https://www.digikey.com/en/products/fil ... PYpAF0BfIA - NTC thermistors
https://www.digikey.com/en/products/fil ... PYpAF0BfIA - PTC thermistors
Please be positive and constructive with your questions and comments.