SLVSCP6H July 2014 – June 2020 DRV10983
PRODUCTION DATA.
The BEMF constant, Kt[6:0] describes the motors phase-to-phase BEMF voltage as a function of the motor velocity.
The measured BEMF constant (Kt) needs to be converted to a 7-bit digital register value Kt[6:0] to program the BEMF constant value. The digital register value can be determined as follows:
The maximum Kt that can be programmed is 1760 mV/Hz. This represents a digital value of 1920 and an encoded Kt[6:0] value of 0x7Fh. The minimum Kt that can be programmed is 0.92 mV/Hz, which represents a digital value of 1 and an encoded Kt[6:0] value of 0x01h.
For convenience, the encoded value of Kt[6:0] may also be obtained from Table 3.
Kt (mV/Hz) | Kt[6:0] | HEX | Kt (mV/Hz) | Kt [6:0] | HEX | Kt (mV/Hz) | Kt [6:0] | HEX | ||
---|---|---|---|---|---|---|---|---|---|---|
0 | 000 0000 | 00 | 29.3 | 010 1000 | 28 | 234 | 101 1000 | 58 | ||
0.92 | 000 0001 | 01 | 33 | 010 1001 | 29 | 264 | 101 1001 | 59 | ||
1.83 | 000 0010 | 02 | 36.6 | 010 1010 | 2A | 293 | 101 1010 | 5A | ||
2.75 | 000 0011 | 03 | 40.3 | 010 1011 | 2B | 322 | 101 1011 | 5B | ||
3.66 | 000 0100 | 04 | 44 | 010 1100 | 2C | 352 | 101 1100 | 5C | ||
4.58 | 000 0101 | 05 | 47.7 | 010 1101 | 2D | 381 | 101 1101 | 5D | ||
5.5 | 000 0110 | 06 | 51.3 | 010 1110 | 2E | 411 | 101 1110 | 5E | ||
6.42 | 000 0111 | 07 | 55 | 010 1111 | 2F | 440 | 101 1111 | 5F | ||
7.33 | 000 1000 | 08 | 58.7 | 011 1000 | 38 | 469 | 110 1000 | 68 | ||
8.25 | 000 1001 | 09 | 66 | 011 1001 | 39 | 528 | 110 1001 | 69 | ||
9.17 | 000 1010 | 0A | 73.3 | 011 1010 | 3A | 587 | 110 1010 | 6A | ||
10 | 000 1011 | 0B | 80.7 | 011 1011 | 3B | 645 | 110 1011 | 6B | ||
11 | 000 1100 | 0C | 88 | 011 1100 | 3C | 704 | 110 1100 | 6C | ||
11.9 | 000 1101 | 0D | 95.4 | 011 1101 | 3D | 763 | 110 1101 | 6D | ||
12.8 | 000 1110 | 0E | 102 | 011 1110 | 3E | 822 | 110 1110 | 6E | ||
13.7 | 000 1111 | 0F | 110 | 011 1111 | 3F | 880 | 110 1111 | 6F | ||
14.6 | 001 1000 | 18 | 117 | 100 1000 | 48 | 939 | 111 1000 | 78 | ||
16.5 | 001 1001 | 19 | 132 | 100 1001 | 49 | 1050 | 111 1001 | 79 | ||
18.3 | 001 1010 | 1A | 146 | 100 1010 | 4A | 1170 | 111 1010 | 7A | ||
20.1 | 001 1011 | 1B | 161 | 100 1011 | 4B | 1290 | 111 1011 | 7B | ||
22 | 001 1100 | 1C | 176 | 100 1100 | 4C | 1400 | 111 1100 | 7C | ||
23.8 | 001 1101 | 1D | 190 | 100 1101 | 4D | 1520 | 111 1101 | 7D | ||
25.6 | 001 1110 | 1E | 205 | 100 1110 | 4E | 1640 | 111 1110 | 7E | ||
27.5 | 001 1111 | 1F | 220 | 100 1111 | 4F | 1760 | 111 1111 | 7F |