ZHCSLS8 August 2020 DRV5825P
PRODUCTION DATA
Spread spectrum is used in some inductor free or inductor less case to minimize EMI noise. The DRV5825P supports Spread Spectrum with triangle mode.
User need configure register SS_CTRL0 (0x6B) to Enable triangle mode and enable spread spectrum, select spread spectrum frequency and range with SS_CTRL1 (0x6C). For 768kHz FSW which configured by DEVICE_CTRL1 (0x02), the spread spectrum frequency and range are described in Table 8-4.
SS_TRI_CTRL[3:0] | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
---|---|---|---|---|---|---|---|---|
Triangle Freq | 24k | 48k | ||||||
Spread Spectrum Range | 5% | 10% | 20% | 25% | 5% | 10% | 20% | 25% |
User Application example: Central Switching Frequency is 768kHz, Triangle Frequency is 24kHz.
Register 0x6b = 0x03 // Enable Spread Spectrum
Register 0x6c = 0x03 // SS_CTRL[3:0]=0001, Triangle Frequency = 24kHz, Spread Spectrum Range should be 10% (730kHz~806kHz)