Appendix 1. Resolution Of The Angle Signal - Renesas RAA3064002GFP User Manual

RAA3064002GFP/RAA3064003GFP
Appendix 1. Resolution of the Angle Signal
This IC outputs a single-phase excitation signal to the resolver sensor. The signal is triggered by the excitation clock signal
(rectangular excitation wave) input from the host MCU. This IC then generates an angle signal (rectangular wave) from the
two-phase signals (electrical angle information) detected by the resolver sensor, and outputs the angle signal to the host
MCU. Angle information can be obtained by using the host MCU to measure the phase difference between the rectangular
excitation wave and angle signal.
The frequency of the excitation signal input to the resolver sensor is selectable as 5 kHz, 10 kHz, or 20 kHz. Select a
frequency that suits the characteristics of the resolver.
The host MCU generates the rectangular excitation wave and handles sampling of the angle signal by using a timer.
The timer's operating frequency and the excitation signal frequency determine the resolution of the angle signal. See figure
A for the relation of the timer operating frequency to the cycle of sampling the angle signal. Figure A shows how raising
the operating frequency of the timer shortens the cycle of sampling the angle signal, i.e. increases the resolution. The cycle
of the rectangular excitation wave also affects the resolution. The points where the angle signal is sampled depend on the
cycle of the rectangular excitation wave. Table A shows how the resolution varies with the timer operating frequency and
the excitation frequency.
Operating clock
for the timer
(40 MHz)
Rectangular
excitation wave
Angle signal
Operating clock
for the timer
(80 MHz)
Rectangular
excitation wave
Angle signal
Figure A Relation of the Timer Operating Frequency to the Cycle of Sampling the Angle Signal
R03UZ0002EJ0120 Rev.1.20
Apr 05, 2021
Points for sampling the angle signal
One cycle of the rectangular excitation wave is
equivalent to an electrical angle of 360 degrees

Appendix 1. Resolution of the Angle Signal

Page 48 of 52