SLVSHO5 April 2024 DRV8215
PRODUCTION DATA
Denoted by W_SCALE, this is a scaling factor which helps in setting the target ripple speed when speed regulation mode is enabled. Settings for W_SCALE are shown below. This register also sets the maximum value of ripple speed under each setting of W_SCALE.
Bit | W_SCALE | Maximum Ripple Speed |
---|---|---|
00b | 16 | 4080 rad/s |
01b | 32 | 8160 rad/s |
10b | 64 | 16320 rad/s |
11b | 128 | 32640 rad/s |
Example setting for W_SCALE: If SPEED register = 15, W_SCALE = 01b, then the actual ripple speed = 15*32=480 rad/s.
Explanation for Maximum Ripple Speed: W_SCALE inadvertently sets the upper limit for the target ripple speed under that setting of W_SCALE. For example, if W_SCALE = 00b, then the maximum ripple speed under this setting = 255*16 rad/s = 4080 rad/s. Hence, the maximum target speed achievable under this setting is 4080 rad/s. Furthermore, under this setting of W_SCALE, FFh corresponds to 4080 rad/s for WSET_VSET when speed regulation mode is activated (REG_CTRL=10b).