SNAS935B March 2025 – November 2025 CDC6C-Q1
PRODUCTION DATA
For EMI reduction, the CDC6Cx-Q1 has orderable options to reduce slew rate and increase rise and fall times. Slowing down the sharp rising and falling edges of a clock output, or lowering the output slew rate, decreases high-frequency harmonics, thereby lessening EMI. For applications requiring lesser EMI, select the appropriate rise and fall time options and see the CDC6Cx-Q1 CISPR25 Radiated Emission Performance Report for more EMI reduction strategies.
The CDC6Cx-Q1 has four slow mode options other than the normal mode. Based on the desired rise and fall times, select the right slow mode option and load capacitance value. Table 8-2 shows the minimum recommended capacitance for each slow mode.
| SLOW MODE | MINIMUM RECOMMENDED CAPACITANCE (pF) |
|---|---|
| Slow Mode 1 | 2 |
| Slow Mode 2 | 5 |
| Slow Mode 3 | 10 |
| Slow Mode 4 | 15 |
Table 8-3 has recommended slow mode options for various load capacitance for a 25MHz output clock. For example, with load capacitance 15pF, Slow Mode 4 option results in the slowest rise and fall times. You can also select Slow Mode 1, Slow Mode 2, or Slow Mode 3 with 15pF but the rise and fall times are faster.
| SLOW MODE OPTION | LOAD CAPACITANCE | RISE AND FALL TIME (ns) WITH SLOW MODE (TYP / MAX) | RISE AND FALL TIME (ns) WITH NORMAL MODE (TYP / MAX) |
|---|---|---|---|
| Slow Mode 1 | 2pF | 0.81 / 1.06 | 0.62 / 1.01 |
| Slow Mode 2 | 5pF | 1.47 / 1.62 | 0.76 / 1.24 |
| Slow Mode 3 | 10pF | 2.44 / 2.61 | 1.4 / 1.7 |
| Slow Mode 4 | 15pF | 3.29 / 3.5 | 1.88 / 2.11 |