EN/FLT

Operation Status

Auto-Restart

Fault

Normal Regulation

Fault Report / Shut Down

200

S

160ms

Figure 7-7. Auto-Restart Operation

7.3.5 VCC Load Recommended Operating Area

Figure 7-8 depicts the device VCC regulation behavior across the output load range, including when the output is

overloaded. For proper device operation, ensure that the device VCC output load does not exceed the maximum

output current IOUT_MAX. If the UCC33020 is loaded beyond the recommended operating area, the VCC will drop

and once it goes below the VCC_UVP threshold, the part enters a power limiting mode to avoid stressing the

device till power stage stop switching and shutdown.

VCC_SET

VCC

Recommended

Operating

Area

IOUT_MAX

IOUT

Power Limit

VCC_UVP

Figure 7-8. VCC Load Recommended Operating Area Description

7.3.6 Electromagnetic Compatibility (EMC) Considerations

UCC33020 devices use adaptive spread spectrum modulation (SSM) algorithm for the internal oscillator to

reduce the noise emmissions from the device. The adaptive SSM algorithm ensures a full switching frequency

span between two bands during each burst cycle regardless of the loading conditions to ensure similar impact

of SSM at different loading conditions. In addition, the UCC33020 uses advanced internal layout scheme to

minimize radiated emissions at the system level.

Many applications in harsh industrial environment are sensitive to disturbances such as electrostatic discharge

(ESD), electrical fast transient (EFT), surge and electromagnetic emissions. These electromagnetic disturbances

are regulated by international standards such as IEC 61000-4-x , CISPR-32 and CISPR-25. Although system-

level performance and reliability depends, to a large extent, on the application board design and layout, the

device incorporates many chip-level design improvements for overall system robustness.

www.ti.com

UCC33020

SLUSFK4A – FEBRUARY 2025 – REVISED MAY 2025

Copyright © 2025 Texas Instruments Incorporated

Submit Document Feedback

21

Product Folder Links: UCC33020