Philips Semiconductors
Control circuit for switched-mode power supply
Product specification
TEA1039
Fig.5
Timing diagram for the frequency regulation mode showing the voltage on external capacitor C5
connected between CX and ground and the output voltage as a function of time for three combinations of
input signals. a: The voltages on inputs FB or LIM are between 2,2 V and 5,9 V. The circuit is in its normal
regulation mode. b: The voltage on input FB or input LIM is lower than 2,2 V. The circuit works at its
maximum frequency. c: The voltages on inputs FB and LIM are higher than 5,9 V. The circuit works at its
minimum frequency.
August 1982
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