ZHCSJY8E june 2019 – february 2021 UCC256402 , UCC256403 , UCC256404
PRODUCTION DATA
As described in Section 7.3.7, BW pin is multiplex for BMTL/BMTH ratio programming. The programming phase happens only once before startup. After that, the BMTL/BMTH ratio is then fixed, until system restarts after a fault or power recycle. The programming phase occurs right before soft start begins. It sources a constant current and measures the voltage on the pin. Depending on the measured pin voltage, different ratio of BMTL/BMTH is selected as listed in Table 7-2. The required BW equivalent resistance is listed in electrical characteristics section.
Other than selecting different BMTL/BMTH ratios, the option 5 also disables the LL/SS pin initial voltage program phase during startup, and the option 7 disables the burst mode.
| Option | BMTL/BMTH |
|---|---|
| 1 | 0.95 |
| 2 | 1 |
| 3 | 0.9 |
| 4 | 0.8 |
| 5 | 0.6 (LL/SS pin initial voltage programming disabled) |
| 6 | 0.6 |
| 7 | 0.4 (Burst Mode Disabled) |