Temperature Sensors Forum - Recent Threads

TMP006EMV project

David V — Wed, 15 May 2013 09:32:23 GMT

Hi,

I'm working on a project , and we are trying to measure (to scan ) a PCB temperature . Eg. we have 10x10 mm board and a like to have 100 point's of temp. measure(1x1 mm).

The TMP006EMV should be 1 to 5 mm away from the target object. I calculated the cover size and attached my calculation for 1mm distance.

1) Can you pleas check the calculation if it's correct?

2) What is the size of cover marked with "?" on the picture?

3) Currently we are using TMP006EMV but in the future we are going to try connect the module on our board without the USB-DIG and I would to know what is the output data of TMP006 on the I2C, It's the object temperature or voltage and what code do I need to use to convert the voltage from I2C to object temperature , do I need to use the TRANSIENT CORRECTION and how?

Regards,

David.

LM95234 with 0201 diode.

Tony Brenke — Wed, 15 May 2013 17:30:14 GMT

I have a SMS7621-060 diode connected to the LM95234 on channel 2. I have a 2n3904 connected to channel 1. the chip set up is as fallows.

read speed = constant diode model = MMBT3904; enable all remote not local; filter enabled on channel 1 and 2.

the output of channel 1 matched the oven temp the output of the 0201 diode falls of at 80C and comes back after the temp lowers again.

what I would like to know is if there is a 0201 diode that any have used that works, even with some adjustment, up to 140-160C OR if there is a setting I can change to get the current diode to operate above the 80C that it crashes at now. I can not change the diode to something larger than an 0201 package. any other options would be very helpful.

Problems with LM95172 at 190C

1898541 — Thu, 18 Apr 2013 00:26:26 GMT

Hi,

LM95172 is a 200C sensor. We are testing it till 190C. Normally when powered up it works well till 190C most of the time. But if we power cycle at 190C the IC stops working. It's connected on a SPI bus. We monitored the SPI bus to see we stopped receiving data when we power cycle the chip at 190C. Once the temperature is lowered to 180C the chip starts responding again with data.

Can you please let us know if this is a known issue or we suppose to do something we are not doing right.

Thanks,

TMP20 Questions

uMin — Thu, 09 May 2013 21:15:10 GMT

Hi,

My customer has an application that requires a very low current consumption temperature switch/sensor, ideally 1uA or less,as it is powered from a coin cell battery. And it has to trigger when the temperature is above 100C. We are considering TMP20.

To save power, we intend to pulse the Vcc of the temperature sensor such that it is 1msec on / 10msec off.

Questions:

The datasheet has a graph (Fig2) Iq vs Temp at Vcc=5.5V, and another graph (Fig4) on Iq vs Vcc at Temp=25C. We need to know the Iq vs Temp (25C to 150C) at Vcc=2.5V. Can we assume it is similar to !q vs Temp at Vcc=5.5V ? Since the Iq is relatively constant from 2.5V to 5.5V at 25C.
What is the response time of TMP20 ? ie. When it is powered from 0 to 2.5V, how long will the output be valid ?
In Fig 10 Thermal Settling, it indicates TMP20 takes about 6 sec to response to a temperature step from 25C to 110C. If Vcc is pulsed with 1msec on / 10msec off, what will be the thermal step response like ?
We inted to add a MOSFET to the TMP20 output to make it works like a Temp switch such that the output is active low when it is above 100C. Any recommendation on the MOSFET or circuit ?
Another "brute force" method is to use a pull up resistor ~1Mohm at the TMP20 output to make it look like an active low output. Will it cause any harm to TMP20 ?

Or, is there other better solution to fulfill the low power (~1uA) temperature switch requirement, which will trigger when >100C ? Accurarcy is not so important, but low power is the key factor.

Thanks,

CM.

connecting LM4F232H5QD and TMP75

Praveen Kumar102474 — Mon, 13 May 2013 08:40:43 GMT

Hi,

I have connected TMP75 with microcontroller LM4F232H5QD; anyone having sample code?

Thanks in advance.

Best regards,

Praveen

LMT84 Supply Current

uMin — Wed, 08 May 2013 11:57:51 GMT

Hi,

Below is a section extracted from page 4 of LMT84 datasheet. (http://www.ti.com/lit/ds/symlink/lmt84.pdf)

On point 5, it says the input current is only 0.001uA. Is that true ? What is the “1uA limit” mentioned ?

On the product page, it states that Iq is 5.4uA typ. What is the difference between the input current and Iq on this part ?

Thanks,

CM.

TMP006 Calibration S0 Variation

Sheng Luo — Mon, 06 May 2013 14:39:05 GMT

Hi,

The question is posted here again because it was not replied for several days.

I have used hot gun to mount 4 TMP006 chips on 4 new boards respectively. The hot gun is Steinel 3483. It was set to 310 degree. Solder flux was applied before soldering. The flux type is Alpha NR-205. The flux was cleaned by ultrasonic cleaner later.

Afterwards, I mounted the board in a plastic box with Fresnel lenses. The focus distance was satisfied. I did the calibration. But the result was not good. In the same system, the S0 of TMP006 varied greatly. The worst case was one TMP006 chip produced negative S0. The others produced positive S0 but the variation was not limited. Below is calibration result list.

device No.	S0
#1	-2.0E-14
#2	6.4E-15
#3	4.0E-15
#4	8.0E-15

What was wrong with my manufacturing process? How to improve S0 variation? Thanks.

BRs,

Luo

TMP006 calculated result stability

Sheng Luo — Mon, 06 May 2013 14:34:37 GMT

Hi,

I have to posted the same question again because I did not receive any feedback from E2E after more than one week. I have used hot gun to mount one TMP006 chip on a new board. The hot gun is Steinel 3483. It was set to 310 degree. Solder flux was applied before soldering. The flux type is Alpha NR-205. The flux was cleaned by ultrasonic cleaner later.

Afterwards, I mounted the board in a plastic box with Fresnel lenses. The focus distance was satisfied. I did the calibration. S0 was about 5.0E-15. When I put a bottle of hot water in front of TMP006, the calculated result was 42 degree at begining. After a while, it rose gradually. Several minutes it reached 62 degree. What was the problem? Thanks.

BRs,

Luo

Temperature sensor for CC2530

Ines Deboub — Fri, 19 Apr 2013 08:51:36 GMT

Hello,

I'm looking for a temperature sensor that is good for measuring the ambient temperature of a room, with SPI and/or I2C interface and suitable for low power applications.

This sensor is about to be interfaced to CC2530 SoC. In fact, i'm using the ZigBee developement kit CC2530ZDK and i must say that i am a beginner in this field.

Thank you for your response.

Best regards.

TMP006 Calculated result stability

Sheng Luo — Mon, 29 Apr 2013 03:33:04 GMT

Hi,

I have used hot gun to mount one TMP006 chip on a new board. The hot gun is Steinel 3483. It was set to 310 degree.
Solder flux was applied before soldering. The flux type is Alpha NR-205. The flux was cleaned by ultrasonic cleaner later.

Afterwards, I mounted the board in a plastic box with Fresnel lenses. The focus distance was satisfied. I did the calibration. S0 was about 5.0E-15.
When I put a bottle of hot water in front of TMP006, the calculated result was 42 degree at begining. After a while, it rose gradually. Several minutes it reached 62 degree.
What was the problem? Thanks.

BRs,

Luo

TMP006 Calibration S0 Variation

Sheng Luo — Mon, 29 Apr 2013 03:29:44 GMT

Hi,

I have used hot gun to mount 4 TMP006 chips on 4 new boards respectively. The hot gun is Steinel 3483. It was set to 310 degree.
Solder flux was applied before soldering. The flux type is Alpha NR-205. The flux was cleaned by ultrasonic cleaner later.

Afterwards, I mounted the board in a plastic box with Fresnel lenses. The focus distance was satisfied. I did the calibration. But the result was not good.
In the same system, the S0 of TMP006 varied greatly. The worst case was one TMP006 chip produced negative S0. The others produced positive S0 but the variation was not limited. Below is calibration result list.

device No.	S0
#1	-2.0E-14
#2	6.4E-15
#3	4.0E-15
#4	8.0E-15

What was wrong with my manufacturing process? How to improve S0 variation? Thanks.

BRs,

Luo

TMP006 register 01h problem

Sheng Luo — Wed, 24 Apr 2013 00:33:52 GMT

Hi,

I have used hot gun to mount 6 TMP006 chips on my new boards. The hot gun is Steinel 3483. It was set to 310 degree. Solder flux was applied before soldering. The flux type is Alpha NR-205. The flux was cleaned by ultrasonic cleaner later.

Afterwards, I tested TMP006 in the lab. I confirmed serial bus firstly. The device ID (register FFh) always returned 0x0067, which was right. One of 6 TMP006 chips returned 0x6D94 (register 01h). The value meant 219.16 degree of ambient physical temperature. It seemed extremely high. It was impossible in the lab. What was problem?

BRs,

Luo

TMP006 energy usage

Harry Snodgrass — Tue, 23 Apr 2013 19:59:20 GMT

Hello,

We are looking at using the TMP006 in a battery operated device (similar to a smoke alarm) that will use a 9 volt battery that needs to have a year long life span. After reviewing the datasheet I see a current usage of 240 uA and it is not clear if this is continuous or a turn on draw, or when sampling for data draw. It is also not clear if this includes the associated circuitry.

Anyone have information on this type of application?

Thanks,

Harry

TMP006 preferred layout details?

Joe Curren57439 — Thu, 10 May 2012 00:42:47 GMT

Hello--
TMP006 Layout and Assembly Guidelines (SBOU108) provides a lot of vital layout info...
but what I can't locate is the recommended BGA pad diameter.
Neither the datasheet nor the YZF package doc indicate this (by way of the device pad size
(which implies, at 1:1, the PCB pad size recommended in the MicroStar BGA doc)).

Scaling Figure 11 in the Guidelines to the 500um pitch and 150um traces, it *appears* that
the pads are 300um, but the image is pretty low-res..... an actual value would help a lot.

Thanks!

TMP302A pullup/pulldown values

Andy Randal — Fri, 19 Apr 2013 11:52:01 GMT

Hi,

Can you please give the recommended pullup/pulldown resistance values for the TMP302A TS0 and TS1 setting inputs?

We are using a 47K pullup to VCC for the TS1 line, and 0 Ohm pulldown to GND for TS0 expecting a 60 Deg C trip, but seem to be tripping at 50 Deg C.

Thanks

TMP100 EVM

Brad Kim — Mon, 15 Apr 2013 10:42:49 GMT

Dear,

Do we have TMP100EVM? it can not be searched by ti.com.

Please advise me shortly~

Thanks.

TMP512 - Trouble Getting Reading from Remote Sensors

David Sorber — Sat, 13 Apr 2013 22:11:54 GMT

I've got a small board with 2 TMP512's that I'm trying to use for remote temperature sensing using discrete transistors. I am not using the power supply monitor functionality of the TMP512 at all. In my design both Vin+ and Vin- are tied to ground and I've disabled the shunt measurement ADC in the Shunt Measurement Configuration Register (0x00). I can read the local temperature result register and it seems to be working great, however when I attempt to read the remote result 1 or 2 registers, bit 0 indicating the Diode Open Flag is always set (I have the remote channels configured for continuous conversion). I'm not sure what I'm doing wrong.

Here are some more details about my design:

My remote sensing transistors are standard 2N3906 BJT's that are diode connected as shown in figure 21 b of the datasheet.
I'm using 560pF filter capacitors for both remote channels, although the sensors are not being placed near any other electrical devices so noise should not be an issue.
I'm using subregulator "Configuration 3" as shown in figure 22 of the datasheet, my V+ is 5V.
After reading the Sensor Fault section of the datasheet I checked the voltage at DXP1 and DXP2 and both fluctuate between 1.23V and 1.29V. This is clearly less than (V+) - 0.6V = 5V - 0.6V = 4.4V in my case.
All of my 2N3906's are brand new, but I've tried 6 of them just to be sure.
I've tried reseting and then reconfiguring the TMP512 multiple times.

I'm really scratching my head on this one, does anyone have any suggestions?

PCB Cleaning Impact on TMP006 Calculation

Sheng Luo — Fri, 12 Apr 2013 00:21:26 GMT

Hi,

I have used hot gun to solder TMP006 on my new board. The hot gun is Steinel 3483. It was set to 310 degree. Solder flux was applied before soldering. I am not sure the flux type. But PCB was not cleaned as far as I knew. Afterwards, I tested TMP006 in a stable enviroment. The calculated object temperature changed from 9 degree to 16 degree even if target object temperature was stable. The range seemed larger than what I expected. So I suspected that there must be something wrong with solder or something else.

Now I look into TMP006 SBOU108. It states PCB cleaning is mandatory in section 5.4. So I guess the problem was caused by flux or residue. Is my guess right? How much does flux or residue impact on temperature accuracy?

BRs,

Luo

Problem in calculating Object temperature Tobj in TMP006 using the fixed point code for 8bit controller.

Dinesh Patil — Sat, 30 Mar 2013 05:49:22 GMT

Hello,

I am having trouble getting the correct value of object temperature tobj using the fixed point code . The value of Tdie is absolutely correct so the sensor TMP006 is working absolutely fine. However the output of the Fixed point calculation code is incorrect . It gives the value of Tobj such that it provides a value (on the LCD) in the range of 32 to 36 degree Celsius no matter what i place in front of it.

Eight TMP006 on a signle bus

Tomoaki Kobayashi — Thu, 23 Jun 2011 10:48:55 GMT

I'd like to know how to control for the eight devices to be addressed on a signale bus. I can see the ADR0/ADR1 state and the SMBus address up to six devices on the data sheet, but not for the 7th and 8th device.

TMP275: Apparent Temperature offset

DG — Mon, 08 Apr 2013 16:45:18 GMT

Hello,

I've got my TMP275-equipped board up and running, but it appears to have a +5/+6°C offset compared to externally measured temperature on the pcb and chip itself. The TMP275 reacts very quickly to temperature changes, and at room temperature, on power up the TMP275 and external probe give the same temperature (22°C). However, as the board heats up, the TMP275 and probe both rise in perfect agreement until about 32°C where the external probe levels off while the TMP275 continues to rise to 38°C. When ambient operating temperature is reached, both probe and TMP275 give steady values (32 & 38°C resp.). The probe displays 32°C whether it is placed on the underside of the pcb or directly on the chip itself.

Any ideas what could cause this, or has anyone seen this before? Is it the underside of the TMP275 that could be at 38°C while the top is at 32°C?

The TMP275 is powered at 3.3Vdc, set to 10-bit resolution, continuous sampling and is read every second. I'm only using the MSB from the Temperature register.

Thanks.

TMP441 Vs=+3.3V AVERAGE IQ

Tomohiko Sugiyama — Mon, 01 Apr 2013 02:14:25 GMT

Our Customer want to know AVERAGE IQ on this condition.(Vs=+3.3V)

Are there any measurement data that Vs = 3.3V Condition of Table 7. Conversion Rate Register ?

Best regards

tmp112 i2c with cc1101 spi

Erkan Ersoy — Fri, 29 Mar 2013 17:40:28 GMT

Hello

I am planing to use tmp112 with pic mcu. spi is shared with i2c interface. i want to use hardware i2c so i need to wire them parallel. In pic i2c open draini so i need to use pull ups. As i seached through tmp112 datasheet there is no chip select pin.

So my question is will i face troubles about it?

Thank you

TMP006 calibration / application question

Jim D. — Mon, 01 Apr 2013 17:24:22 GMT

We've read many of the posts here related to the TMP006, and downloaded useful calibration spreadsheets and sample code.

In our application the TMP006's field of view will be the underside of a heatsink we wish to monitor. An accuracy of +/-3 C is acceptable over Tdie and heatsink range of -20C to +70C. In our application, Tdie and heatsink temp are not related and don't trend together. We can gather two calibration points with a constant Tdie to obtain our calibration constant - at the lowest and highest expected heatsink temperatures. We intend to use the 'transient temp correction' discussed in this forum.

My questions are:

1) Is the calibration data taken at Tdie=20C still valid for calculating the remote temp in actual use when Tdie varies between -20C and +50C?

2) Is the calculated remote temp accurate if the remote temp is significantly colder (say -10C) than Tdie, and Tdie is significantly higher than when the cal data was taken (say Tdie=50C)?

3) Can the cal data be gathered at elevated Tdie (say 50C) if we can hold Tdie constant? (remote temp would be -20C to +70C)

Thanks,

Jim D.

Problems with I2c(TWI) with TMP006 .

Dinesh Patil — Sun, 24 Mar 2013 01:21:50 GMT

I am trying to interface TMP006 with ATmega32u4 through I2c(Two wire interface), but the slave device (TMP006) is not providing the acknowledge on providing the address on the sda line. 400khz SCL frequency was selected and the slave address set was [0x80 i.e. SLA+W]. The Start action of the microcontroller was verified. I cant seem to understand why the acknowledge isnt being provided by tmp006.

Could this be because the voltage levels provided by TMP006 are not sufficient enough for the micro controller to notice. I have used pull ups of 10K on the I2C lines.

I have provided a supply of 3.3 volts to TMP006.