Does AD734 need heatsink? it's inside goes hot.
One more thing, the output is not the desired output. U=10 and (x1-x2)=2mv DC. (y1-y2)=10v sin . So we calculate 2mv output BUT the output is around 4vac sin.
Can you kindly share your schematic? How do you connect AD734 to achieved the multiplier circuit? I suspect the heating problem might be the results of improper connection. The DS states that the maximum internal power dissipation of the device should be 500mW can you kindly check that.
Hi and thanks for replay.
this is the schem
Thanks for the schematic. I just realized that you are actually doing something unachievable with ad734. You are expecting to get 2mV output with your x and y input (10V sin * 2mV DC) / 10 but the input offsets of X, Y and Z are already at the range of 15mV to 20mV which is obviously larger than your expected output. I suggest you get your input pre amplify (X) by a very large number say 1000 by a very good precision amplifier from whichever source that signal is coming from (or please let us know so we can suggest appropriate amplifier). Multipliers usually has quite large offsets that's why small signal became really a big problem.It more likely to give you unexpected results. If you could also give us some details of your application, it will be much helpful. Regarding the heating problem, please kinldy check if you're connections are all correct and observe the power consumption not to exceed 500mW.
I also want to recommend to do some simulations if you llike with our ADIsimPE powered by SIMetrix/SIMPLIS with AD734 SPICE model so that you can get some ideas on the operation of this device.
Thanks for replay again .
The "X" pair input coming from ADXRS623 gyroscope and it has 12.5 mv per each deg/sec speed. so we know that our DC steps are around 12.5 mv. I didn't payed any attention to input offset.
I was exploring in AD devices and i saw some Multiplayer with around 2mv offset(AD534-AD6320), so i thinks they are more ideal than AD734 for my application.
About heating problem, i just tested the device out of board with no input just with it's supply. around +-15v again i saw heating problem but it is not much maybe ~45 deg c. the consumption current is 10mv.
i just tested out of PCB.
I'm really confused! AD734's temperature increasing while working. it works fine but i think the temperature rising is not usual. Don't you?
Good to hear that your circuit is working. For the heating problem, it's hard to say whether it's normal or not if we can't measure the temperature your saying. What we want ot know is what is that temperature? how fast it rise? Or what is the power consumption (current multiply by voltage supply) of the device when working properly and do you have any resistor at the output or load? I'll try to get some data if I can replicate your setup.
BTW. What's the package you're using?
I think i just found out what was the problem.
The supply voltage was 30v(-15 +15). i just reduced the supply voltage to 20(-10 +10) the heating problem became better. But i saw in datasheet that the absolute max power supply is -18 +18.
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