ZHCSFR6C December 2016 – January 2018 TPS22810
PRODUCTION DATA.
A capacitor to GND on the CT pin sets the slew rate. The voltage on the CT pin can be as high as 2.5 V. An approximate formula for the relationship between CT and slew rate is shown in Equation 3. This equation accounts for 10% to 90% measurement on VOUT and does NOT apply for CT < 1 nF.
Use Table 2 to determine rise times for when Ct ≥ 1 nF.
where
Rise time can be calculated by dividing the input voltage by the slew rate. Table 2 contains rise time values measured on a typical device. Rise times shown below are only valid for the power-up sequence where VIN is already in steady state condition before the EN/UVLO pin is asserted high.
| CT (pF) | RISE TIME (µs) 10% - 90%, CL = 0.1 µF, CIN = 1 µF, RL = 10 Ω | ||||
|---|---|---|---|---|---|
| VIN = 18 V | VIN = 12 V | VIN = 9 V | VIN = 5 V | VIN = 3.3 V | |
| 0 | 115 | 91 | 78 | 60 | 98 |
| 470 | 136 | 94 | 80 | 63 | 98 |
| 1000 | 310 | 209 | 158 | 91 | 102 |
| 2200 | 688 | 464 | 345 | 198 | 135 |
| 4700 | 1430 | 957 | 704 | 397 | 265 |
| 10000 | 3115 | 2085 | 1540 | 864 | 550 |
| 27000 | 8230 | 5460 | 4010 | 2245 | 1430 |