SLOSEA8 December 2024 TAS5815
PRODUCTION DATA
It is required that the peak current is smaller than the OCP (Over current protection) value which is 7A (Typical), there are 3 cases which cause high peak current flow through inductor.
θ=0.5 (BD Modulation), 0.14 (1SPW Modulation), 0.14 (Hybrid Modulation). This formula just provide a rough estimation, suggest to measure the start-up current based on your LC filter.
PVDD | L (uH) | C (uF) | Fsw (kHz) | Ipeak_power_up |
---|---|---|---|---|
24 | 4.7 | 0.68 | 384 | 6.07A |
24 | 4.7 | 0.68 | 768 | 3.25A |
24 | 10 | 0.68 | 384 | 3A |
24 | 10 | 0.68 | 768 | 1.55A |
12 | 4.7 | 0.68 | 384 | 3.32A |
12 | 10 | 0.68 | 384 | 1.55A |
Same PVDD and switching frequency, larger inductance means smaller idle current for lower power dissipation. It's suggested that inductor saturation current ISAT, is larger than the amplifier peak current during power-up and play audio.
In addition, the effective inductance at the peak current is required to be at least 80% of the inductance value in Table 9-2 to meet datasheet specifications.
Switching Frequency (kHz) | Modulation Scheme | Recommended Minimum Inductance (uH) for LC filter design |
---|---|---|
1024 | 1SPW | 3.3 µH (or larger) + Capacitor (0.22uF~0.68uF) |
768 | 4.7 µH (or larger) + Capacitor (0.22uF~0.68uF) | |
384 or 480 | 10 µH (or larger) +Capacitor (0.22uF~0.68uF) | |
384~1024 | BD | 8.2uH (or Larger) +Capacitor (0.22uF~0.68uF) |
For inductor selection refer to LCFILTER-CALC-TOOL.