SNVSBZ6 May 2021 TPS92380 , TPS92381
PRODUCTION DATA
TPS9238x has an optional spread spectrum feature (±3% from central frequency, 1-kHz modulation frequency) which reduces EMI noise at the switching frequency and its harmonic frequencies. If SYNC pin level is low, spread spectrum function is disabled. If SYNC pin level is high, spread spectrum function is enabled.
TPS9238x DC-DC converter can be driven by an external SYNC signal between 300 kHz and 2.2 MHz. When external synchronization is used, spread spectrum is not available. If the external synchronization input disappears, DC-DC continues operation at the frequency defined by RFSET resistor and spread spectrum function will be enabled/disabled depending on the final SYNC pin level.
External SYNC frequency must be close to the frequency defined by RFSET resistor. In external SYNC configuration, minimum frequency setting with RFSET could go as low as 250 kHz to support 300-kHz switching with external clock.
SYNC PIN INPUT | MODE |
---|---|
Low | Spread spectrum disabled |
High | Spread spectrum enabled |
300 to 2200-kHz frequency | Spread spectrum disabled, external synchronization mode |