Three-Wire, Differential, Vibration Resistant

Sensor IC with Speed and Direction Output

ATS693LSG

10

Allegro MicroSystems, LLC

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

TIMING

As shown in figure 5, the pulse appears at the output slightly

before the sensed magnetic edge traverses the package branded

face. For targets in forward rotation, this shift, Δfwd, results in

the pulse corresponding to the valley with the sensed mechanical

edge, and for targets in reverse rotation, the shift, Δrev, results in

the pulse corresponding to the tooth with the sensed edge. The

sensed mechanical edge that stimulates output pulses is kept the

same for both forward and reverse rotation by using only one

channel to control output switching.

Direction Validation

Following a direction change in Running mode, output pulses are

not present until direction information is validated. An example

of the waveforms is shown in figure 6.

Reverse Rotation

Forward Rotation

Tooth

Valley

∆rev

Output Pulse

(Forward Rotation)

Output Pulse

(Reverse Rotation)

∆fwd

t

t

t

t

t

Target

Differential

Magnetic

Profile

Target Rotation Forward

Target Rotation Reverse

Target

Differential

Magnetic

Profile

Target Rotation Forward

Target Rotation Reverse

Target

Differential

Magnetic

Profile

Target Rotation Forward

Target Rotation Reverse

Tooth

Valley

Tooth

Valley

Tooth

Valley

Figure 5: Output Protocol

Figure 6: Example of Direction Change in Running Mode