L9369 getting voltage from SH1, SH2
Hello. ST team.
i'm using L9369's voltage measurement function.
i read L9369 manual, and i send below SPI commands(no.0~6) for initial driving.
(my purpose is to drive FET : HS1 A, B ON / LS2 A,B ON)
| 0 | 0xb5019ff8 |
| 1 | 0xb5a15fef |
| 2 | 0xb720b54d |
| 3 | 0xb480aa98 |
| 4 | 0x40a0000d |
| 5 | 0xbb8020ea |
| 6 | 0xc3a000f5 |
after sending above SPI commands to check SH1/2_A/B's voltage AD read.
| 14 | 0x0c20001f |
| 15 | 0x0d000010 |
| 16 | 0x0e200001 |
| 17 | 0x0f00000e |
| 18 | 0x1020001a |
| 19 | 0x1620001d |
| 20 | 0x17200012 |
| 21 | 0x1800000d |
| 22 | 0x19200002 |
| 23 | 0x1a000013 |
| 24 | 0x11000015 |
| 25 | 0x12200004 |
| 26 | 0x1300000b |
| 27 | 0x14200003 |
| 28 | 0x1500000c |
| 29 | 0x1b00001c |
| 30 | 0x1c200014 |
| 31 | 0x1d00001b |
| 32 | 0x1e20000a |
| 33 | 0x1f000005 |
after sending above SPI commands, i checked measured data, but the measured voltage is approximately 0.6V lower than the actual measurement value obtained through the oscilloscope.
After completing the above operation, I send the following SPI commands(no.7~13) again.
(my purpose is to drive FET : HS2 A, B ON / LS1 A,B ON)
| 7 | 0xb5019ff8 |
| 8 | 0xb5a0bfea |
| 9 | 0xb7015548 |
| 10 | 0xb4a0aa98 |
| 11 | 0x4080000d |
| 12 | 0xbba020ea |
| 13 | 0xb401994d |
After sending above SPI commands(no.14~33), i measure SH1/2_A/B's voltage again.
In the second operation, I confirmed that the values measured with the SH pin's AD value and those measured with the oscilloscope were nearly same.
My question is this: Why is the voltage output approximately 0.6V lower in the first operation? What SPI settings do I need to configure? (All four ACT_OFF_LS pins are in a low state after the first operation, switched to a high state to stop the H-bridge after the first operation, and then switched back to low just before the second operation to enable the H-bridge again.)
please let me know. thank you.