TEA1781T; TEA1782T
GreenChip PC secondary control ICs
Rev. 01 — 13 February 2009
www.datasheet4u.com
Preliminary data s...
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 Over
Voltage Protection (OVP). These v...