Philips Semiconductors
GreenChip™II SMPS control IC
Product specification
TEA1552
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.
GENERAL DESCRIPTION
The GreenChip™(1)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.
The proprietary high voltage BCD800 process makes
direct start-up possible from the rectified mains voltage in
an effective and green way. A second low voltage
BICMOS IC is used for accurate, high speed protection
functions and control.
Highly efficient, reliable supplies can easily be designed
using the GreenChipII control IC.
(1) GreenChip is a trademark of Koninklijke Philips
Electronics N.V.
2002 Aug 27
2