UCC2897A: What is ENABLE signal / When does switching start

Ella KIM

Part Number: UCC2897A

Hello Team,

In the datasheet p12, what's ENABLE waveform referring to?

As per description in datasheet below, PWM pulse will be inactive during the standby mode (I understand 'standby mode' is referring to the period that VDD is repeating charging and discharging by JFET). But as per figure 19, PWM pulse is active in accordance to ENABLE, even during the standby mode period.

Could you please clarify when PWM pulse starts to appear?

Thank you.

over 4 years ago

+1 Hong Huang over 4 years ago

TI__Guru 74095 points

Hi,

It is an internal signal and showing to indicate when the IC is enabled and when not enabled.

0 Ella KIM over 4 years ago in reply to Hong Huang

TI__Expert 4212 points

Hi Hong,

Thank you for the information. Can I expect the duration of the first ENABLE period and the duration of OFF period before IC is ENABLEed again? Is it internally designed, or depending on the external operating condition?

+1 Hong Huang over 4 years ago in reply to Ella KIM

TI__Guru 74095 points

Hi,

The diagram shows enable in relation with other signals. If other signals keep the same, then enable will keep the same. Yes, enable is controlled by the show external signals (the top two for the first enable). The first enable off is due to SS pull down.

Power management

Power management forum

UCC2897A: What is ENABLE signal / When does switching start