GreenChip SMPS control IC
Rev. 01.11 — 10 July 2009
1. General description
The TEA1733 is a low cost Switched Mode Power Supply (SMPS) controller IC intended
for flyback topologies.
The TEA1733 operates in fixed frequency mode. To reduce EMI, frequency jitter has been
implemented. For Continuous Conduction Mode (CCM) operation, slope compensation is
integrated. The controller can be set to accept an over-power situation for a limited
amount of time.
Two pins are reserved for protection purposes. Input under and over voltage protection,
output over voltage protection and over temperature protection can be implemented with a
minimal number of external components.
At low power levels the primary peak current is set to 25% of the maximum peak current
and the switching frequency is reduced to limit the switching losses.
The combination of fixed frequency operation at high output power and frequency
reduction at low output power provides high efficiency over the total load range.
The TEA1733 enable low cost, highly efficient and reliable supplies for power
requirements up to 75 W to be designed easily and with a minimum number of external
SMPS controller IC enabling low cost applications
Large input voltage range (12V up to 30V)
Very low supply current during start-up and restart (typ. 10μA)
Low supply current during normal operation (typ. 500μA without load)
Adjustable over-power time-out
Adjustable over-power restart timer
Fixed switching frequency with frequency jitter to reduce EMI
Frequency reduction with fixed minimum peak current at low power operation to
maintain high efficiency at low output power levels
Slope compensation for CCM operation
Low and adjustable over current protection (OCP) trip level