NCP1623ADR2G

NCP1623 is a critical conduction mode (CrM) power factor correction controller. It is a controller designed to drive PFC boost stages. Based on an innovative valley synchronized frequency fold-back (VSFF) method, it operates in critical conduction mode (CrM) until the power drops below a threshold level. The PFC controller enters discontinuous conduction mode (DCM) with increased dead-time as the load further decays (frequency foldback). VSFF maximizes the efficiency at both nominal and light loads. An internal circuitry ensures a near-unity power factor even when the switching frequency is reduced. The circuit also incorporates the features necessary for robust and compact PFC stages, with few external components. The A version provides the follower boost capability for drastic low-line efficiency improvement. Applications are power factor correction, offline power supply, USB−PD, flat TV, industrial power supplies, all off−line appliances requiring power factor correction.

• Follower boost capability, dynamic response enhancer
• Zero current detection via drain sensing
• Near unity power factor over the load range
• Maximizes the efficiency at both nominal and light loads
• Maximizes the efficiency at both nominal and light loads
• Improves low line and full load efficiency
• Improves no load and ultra light load efficiency
• Simplifies PFC inductor design, eliminates auxiliary winding
• Fast line and load transient response, meets typical power supply spec
• SOIC−8 package, sleep mode with circuit consumption below 100µA