GENERAL DESCRIPTION
The GreenChip™II is the second generation of green Switched Mode Power Supply (SMPS) control ICs operating directly from the rectified universal mains. A high level of integration leads to a cost effective power supply with a very low number of external components. The special built-in green functions allow the efficiency to be optimum at all power levels. This holds for quasi-resonant operation at high power levels, as well as fixed frequency operation with valley switching at medium power levels. At low power (standby) levels, the system operates at reduced frequency and with valley detection.

FEATURES
Distinctive features
• Universal mains supply operation (70 to 276 V AC)
• High level of integration, giving a very low external component count.

Green features
• Valley or zero voltage switching for minimum switching losses
• Efficient quasi-resonant operation at high power levels
• Frequency reduction at low power standby for improved system efficiency (<3 W)
• Cycle skipping mode at very low loads. Pi < 300 mW at no-load operation for a typical adapter application
• On-chip start-up current source
• Standby indication pin to indicate low output power consumption.

Protection features
• Safe restart mode for system fault conditions
• Continuous mode protection by means of demagnetization detection (zero switch-on current)
• Accurate and adjustable overvoltage protection (latched)
• Short winding protection
• Undervoltage protection (foldback during overload)
• Overtemperature protection (latched)
• Low and adjustable overcurrent protection trip level
• Soft (re)start
• Mains voltage-dependent operation-enabling level
• General purpose input for lock protection.

APPLICATIONS
Typical application areas are adapters and chargers (e.g. for laptops, camcorders and printers) and all applications that demand an efficient and cost-effective solution up to 250 W.