Speed (Magnetic sensor) Forum Discussions

Hello, there is a statement in the datasheet of the part number TLE4953C, which I do not completely understand.

It is the definition in Table 3-4 Electrical Characteristics, that states the 'Number of emitted pulses with invalid direction Information'.

1) What is the definition of 'invalid direction information'? Does it mean, the direction can be wrong (120 us instead of 60 us and vice versa) or does it mean, there could be no direction information available and the IC issues 30 us (speed pulse) instead?

2) If the gear wheel is rotating in a particular direction and I apply the supply voltage - do I have to assume, the direction information could be wrong (forward instead of reverse and vice versa) for up to 2 pulses?

Thank you for your support. Regards

what's the different of speed senor's :

Type of Hysteresis : hidden fixed; hidden adaptive; visible fixed; visible adaptive

TLE4941, TLE4943, TLE4953, 

Thanks

Hello Community,

we use the  TLE4957CE6747 but this part will no longer produced. We found the following part at a distributor:

TLE4957C2NE6747HAMA1, INF |OBS | 47,800 St. order code is SP000745378

Can we replace our 4957CE with the part above? The part we use (TLE4957CE6747)

shows order number SP000649296, will this fit?

What does the N stand for?

What does HAMA1 stand for?

Thank you for your feedback and best regads

Dear support,

I have got a couple of questions regarding the magnetic operating conditions of the device.

The IC will be used in a configuration with back-biasing. 

The following operating conditions are stated in the datasheet of TLE4953C:

1. Pre-induction: +/- 500 mT
   My understanding ist, that the dynamic range is maximum +/- 500 mT on all three channels (L, R, C) and for me as an integrator I have to ensure that this limit is not exceeded, even at the minimum possible air gap? Basically the flux density has always to be below +/- 500 mT for all three hall elements? Is this understanding correct?
2. Pre-induction offset between outer probes: +/- 20 mT
   Suppose the dB = L-R signal is non-symmetrical. The positive peak is 42 mT and the negative peak is 0 mT. The peak-to-peak value would be within the specification, but there would be an offset of 21 mT present. Does this limit refer to (max(dB)-min(dB))/2<20 mT? If my understanding is correct, I would not maintain the allowed operating range? 
3. Pre-induction offset between mean of outer probes and center probe: +/- 20 mT
   Basically same question as point 2.  I calculate based on this equation dBdir = (L+R)/2-C the differential directional signal and check (max(dBdir)-min(dBdir))/2<20 mT? Is this again the correct approach?  I attached some simulation results for a non-symmetrical Bdir case (upper plot raw flux densities, then dB and dBdir).
4. Differential: +/- 120 mT
   Does this value refer to the positive and negative peak of the dB = L-R signal?
5. Note: Limit threshold speed 0Hz ≤ f ≤ 2500Hz +1.5 mT. The stated condition is 50% missing pulses. Is there as well a flux density limit for which let's say 99.99966 % of all pulses are detected. I used guard banding by using dB >= 4 mT as the allowed lower limit for the simulation, but I am not sure what the expectation for the missing pulses would be.
6. Note: Limit differential direction signal 0Hz ≤ f ≤ 1100Hz +0.73 mT. The stated condition is: "just one pulse missing out of 100". Does that mean, there will be no directional pulse width shown on the output for this single pulse or the entire pulse is missing?

 Thank you for your support.

Regards