Data Sheet

12

Information about the application circuit of the TLE 4917

Application circuit TLE 4917

The minimum value for the pull up resistor can be calculated with the power supply voltage

Vs, the maximum current I

Example:

for Vs = 3 V: R

Larger values for R

resistor RL is very large (>100 k

Ω) a capacitor (app. 10pF) between Output and GND pin

could be useful if capacitive coupled noise occurs.

The load at the output Q should have a large input resistance to reduce the current trough

R

The TLE 4917 has 3 ground pins. From a mechanical point of view all ground pins should

be connected to ground. Shortest wires should be used to avoid ground loops.

If there is a need to reduce the number of used ground-pins any ground-pin combination

may me used. Furthermore it is possible using only one ground-pin at the application, all

pins are equivalent.

The capacitor C is highly recommended to reduce noise on the power supply voltage and it

will improve the EMI/EMC performance.

Furthermore it decreases the transient peak supply current during operation time. The IC

toggles between low and high current consumption. This behaviour might produce

additional noise at the power supply. The capacitor will reduce this noise.

Furthermore this capacitor is used to supply the sensor if microbreaks (short loss of supply

voltage) occur.

Shortest connection wires between IC and capacitor should be used to avoid noise.

The switch S1 shows the programming feature of the output.

Example:

If the PRG-pin is connected to Vs the IC will hold the output Q at a high voltage level for B= 0 mT in this circuit. A

magnetic field larger than the operating point will switch the output to low level. In typical applications the PRG-pin is

connected directly to Vs or to GND depending on the technical needs. Avoid using a floating PRG-pin.

1 Vs

C= 10 nF

Ω

Sensor

Output

2 Gnd

3 Q

6 Prg

5 Gnd

4 Gnd

S1

Gnd

TLE 4917