AK7451 Datasheet, PDF (26/32 Pages) Asahi Kasei Microsystems – zero latency angle sensor ic

[AK7451]
16. ABZ Output Figure
The ABZ output is following figure; The A and B are 1024pulses and Z pulse is outputted with one pulse
during a rotation. (The number of A and B pulse is settable via SPI.). Moreover, the Z phase can be set to
“Normal Output” which toggle at 0 degree position and “Switch Output” which keeps low state in more
than 180 degree and high state in less than 180 degree.
B
A
Z
360°(4096 code)
B
A
Z
180°(2048 code)
360°(4096 code)
Z phase normal output
selection
Z phase switch output
selection
Figure 9. ABZ Output figure
Note 28. Z-phase Output corresponds to the Zero point configuration which should be set by user.
The ABZ output is generated by the bit operation from 12 bit absolute angle data.
In order to generate the ABZ output, the angle data ANG[11:0] is once changed into ANG_ABZ[11:0] by
the following operation.
ANG_ABZ[11:0] = absolute angle data ANG[11:0] × (ABZ resolution set value ABZ_RES[ppr] ×4 ) ÷ 4096
Then, From obtained ANG_ABZ[11:0], the A phase is generated by Bit1, and B phase is generated by
Bit1  Bit0. Z phase is generated by NOR all 12bit data.
Note 19. When the ABZ output is except a exponentiation setup of 2, the angle linearity error
deteriorates in range of -1 to 0 LSB(-0.088 to 0 degree.).
016006637-E-00
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2016/05