SLVAF45 August 2021 TPS51397A , TPS566231 , TPS566235 , TPS566238 , TPS568230
For TPS568230 Ioutmax=8 A, Vref=0.6 V. Co in the table are effective value considering degrading. The large Cff as 1000 pF can be allowed from loop stability view, but it could inject more high frequency noise into feedback and also might affect converter operation. The Cff theoretical calculation methods must be used combined with real situation and bench test results.
Vin (V) | Vo (V) | fsw (kHz) | Rtop/Rbottom | Llimits (uH) | Lchoose(uH) | Co (uF) | Cff limit | Cff choose (pF) | PMtest (deg) |
---|---|---|---|---|---|---|---|---|---|
6 | 2.5 | 600 | 95 kΩ/30 kΩ | 0.76-1.52 | 1 | 200 | Cff>56pF | 70 | 81.4 |
1000 | 50.8 | ||||||||
6 | 3.3 | 600 | 90 kΩ/20 kΩ | 0.77-1.55 | 1 | 200 | Cff>68 pF | 80 | 80.2 |
1000 | 47 | ||||||||
18 | 2.5 | 600 | 95 kΩ/30 kΩ | 1.12-2.24 | 1.5 | 200 | Cff>69 pF | 82 | 80 |
1000 | 63 | ||||||||
18 | 3.3 | 600 | 90 kΩ/20 kΩ | 1.4-2.81 | 2.2 | 200 | 100-236 pF | 110 | 83 |
220 | 75 | ||||||||
18 | 5 | 600 | 220 kΩ/30 kΩ | 1.88-3.76 | 2.2 | 200 | 51-147 pF | 62 | 72 |
140 | 77 |