SPRSP45C March 2020 – April 2024 TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1
PRODUCTION DATA
A server or telecom power supply unit (PSU) consists of a power factor correction (PFC) stage and a DC-DC converter stage. The Totem pole PFC is widely used as the PFC stage. For the DC-DC stage, LLC and phase-shifted full bridge (PSFB) are the two most popular topologies. Usually, current server PSU is based on a two-chip architecture, as shown in Figure 8-3. Telecom PSU is more likely to have a single-chip architecture, as shown in Figure 8-4.
The PFC stage draws sine-wave current from the AC mains in phase with the AC voltage, and maintains a steady DC bus voltage (VDC, typically +400 V) across its output. This output voltage is applied to the input of DC-DC stage, which converts it to an isolated low-output voltage Vout (12 V/48 V for server, 48 V for telecom).