AK8779A Datasheet, PDF (7/13 Pages) Asahi Kasei Microsystems – Hall Effect IC for Pulse Encoders

[AK8779A]
10.3. Behaviors of Internal and Output Signals when a Rotating Magnetic Field Is Applied on
The AK8779A
The F signal (pulse) is correspond to the result of EX-OR operation of internal signal A and B. The D
signal (direction) is calculated by status of internal signal A and B.
Vertical M. F. D.
BopV
BrpV ⁰
Direction changed
Direction changed
t
BopH
Horizonatal M. F. D.
BrpH ⁰
t
Supply voltage V_DD
0
t
Internal signal A
(Vertical)
0
t
Internal signal B
(Horizontal)
0
t
F (Pulse)
0
t
D (Direction)
0
t
Undefined ("H" or "L")
F, D signal is determined.
Figure 6. Behaviors of Internal Signal A, B and Output Signal F, D with Rotating Magnetic Field
* M.F.D. = Magnetic Flux Density
* D signal is determined after one F signal pulse is sent out. The indeterminate output state appears
only in the powering up of this device.
* F and D signals are changed at the same time.
015001035-E-02
-7-
2015/07