TEA1782T

TEA1781T; TEA1782T GreenChip PC secondary control ICs Rev. 01 — 13 February 2009 www.datasheet4u.com Preliminary data sheet 1. General description The TEA1781T and TEA1782T are designed to cooperate with the TEA1771T primary side controller in a unique converter topology based on the active clamp forward converter. On the secondary side the output voltages are regulated via bidirectional switches. A typical application area of this converter is a power supply for a desktop PC. The TEA1781T and TEA1782T are secondary control ICs and regulate each output voltage independently of the primary duty cycle and other secondary output voltages. Because of these separated regulations, the system does not show any cross regulation and makes the design of the transformer easier. As each output can also be completely turned off, the system allows for an integrated standby supply. To maximize the efficiency in Standby mode, the duty cycle and operating frequency are minimized in Standby mode. The TEA1781T and TEA1782T have integrated drivers and individual output voltage regulators. In this way the 3.3 V, 5 V, 12 V and 5 V standby outputs of a typical PC power supply are regulated separately giving accurate output voltages and fast transient response. All requirements according to the Intel ATX specification (V 2.0) are integrated, such as soft start, a PS_ON# connection, a PwrOK signal and all required protections like OverCurrent Protection (OCP) and OverVoltage Protection (OVP). These v...