ZHCSM62C September 2020 – December 2021 TPS542A50
PRODUCTION DATA
The internal oscillator of the device can be set to one of seven switching frequencies by a resistor to ground on the FSEL pin or through I2C programming. The FSEL pin can be shorted to ground to reduce BOM component count. When shorted to ground, the default converter switching frequency is used. If the user programs the switching frequency using the I2C interface, TI recommends shorting the FSEL pin to ground to reduce component count. The following frequencies can be programmed on the FSEL pin.
| RFSEL (kΩ) | fSW (kHz) |
|---|---|
| Short | 1000 |
| 7.5 | 400 |
| 18.2 | 600 |
| 26.1 | 800 |
| 35.7 | 1000 |
| 47.5 | 1200 |
| 61.9 | 2000 |
| 78.7 | 2200 |
The oscillator can also be synchronized to an external clock on the SYNC pin. The external clock frequency must be within -10% and +15% of the programmed frequency of the converter. The SYNC pin has an internal pulldown so it can be left floating externally.
When the converter operates at 2 MHz or 2.2 MHz, it is recommended to set the OCP at 13 A or lower and without a snubber circuit. For operation with OCP at 16.5 A, a snubber circuit is required. The snubber circuit components can start with a 470-pF cap and 2-Ω resistor to help reduce voltage ringing levels. It is recommended for the ringing levels to be 2-V below the Absolute Maximum Ratings between SW and GND at room temperature. The component values will need to be tuned to achieve optimal results.