Data Sheet

3

Ver. 1.0

2019-07

TLE4959-5U-R Transmission Speed Sensor

Functional Description

1

Functional Description

The differential Hall sensor IC detects the motion of tooth and magnet encoder applications. To detect the

motion of ferromagnetic objects, the magnetic field must be provided by a back biasing permanent magnet.

Either south or north pole of the magnet can be attached to the rear unmarked side of the IC package (See

Figure 2). The magnetic measurement is based on three equally spaced Hall elements, integrated on the IC.

Both magnetic and mechanical offsets are cancelled by a self calibration algorithm.

The sensor includes a voltage output PWM protocol.

1.1

Definition of the Magnetic Field Direction

The magnetic field of a permanent magnet exits from the north pole and enters the south pole. If a north pole

is attached to the backside of the High End Transmission Sensor, the field at the sensor position is positive, as

shown in Figure 2.

Figure 2

Definition of the Positive Magnetic Field Direction

1.2

Block Diagram

Figure 3

Block Diagram

S

Tooth

Notch

Notch

IC Branded

Side

S

IC Branded

Side

Tooth

Notch

Notch

Digital-Core:

Min/Max -detection

Offset-calculation

Hysteresis-calculation

Offset compensation

Direction detection

Vibration suppression

Output-protocol

Q

GND

Open

Drain

Hall

Direction-

sensing

Compensated

Amplifier and

Tracking ADC

Diff. Hall

Speed-sensing

PMU:

Chopper switches

Separated supplies

Bandgap (Temp. Compensated)

Compensated

Amplifier and

Tracking ADC