AK7451 Datasheet, PDF (27/32 Pages) Asahi Kasei Microsystems – zero latency angle sensor ic

[AK7451]
17. UVW Output Figure
This is a function which outputs the UVW signal which is needed for a DCBL motor drive. The UVW
output can be set in the range of 1-8 pulses to one rotation. Moreover, U, V and W signal has 120 degree
phase difference in an electric angle respectively. The zero point setup is reflected to start position of
UVW.
Regarding the zero point setup, see the “ZP Register/Memory” setup in section 14.
U
V
W
Rotatio
n Angle ^0
60
120 180 240
In case of 1 pulse setup
300 360
U
V
W
Rotatio
n Angle ^0
60
120 180 240
In case of 2 pulse setup
300 360
Figure 10. UVW Output figure
If there is difference between UVW and ABZ hysteresis, the start position of UVW phase shifts by the
difference of UVW and ABZ hysteresis setup.
In order to generate the UVW output, the angle data ANG[11:0] is once changed into ANG_UVW[5:0] by
the following operation.
ANG_UVW[5:0] = absolute angle data ANG[11:0] × (the number of UVW pulse set value UVW_RES[ppr]
×6 ) ÷ 4096
By using obtained ANG_UVW[5:0], each U, V and W phase signal is generated as following.
U : When ANG_UVW [5:0] value is from 6N to 6N+2, an output is high-level, and it is a low level when
other.
V : When ANG_UVW [5:0] value is from 6N+2 to 6N+4, an output is high-level, and it is a low level when
other.
W : When ANG_UVW [5:0] value is from 6N+1 to 6N+3, an output is low-level, and it is a High level when
other.
Here, N means the order of output pulses. (from 0 to the number of pulses -1).
016006637-E-00
- 27 -
2016/05