The RT7755xE series operating with continuous conduction mode (CCM) is specifically designed to work with controllers, such as the RT7206, to provide a total solution for USB PD or a programmable power adapter. This RT7755xE not only provides a high power efficiency control scheme, but also gives a 50mW very low standby power control under 5V standby condition.
The RT7755xE is such a special design to achieve a wide-range of output voltage by utilizing several innovations, including (1) By using DMAG pin, the RT7755xE senses output voltage to adjust loop gain for system stability, to adjust output over-voltage protection threshold voltage to protect external devices, and to adjust current limit to meet Limited Power Source (LPS) safety requirements; (2) The RT7755xE is also equipped with comprehensive protection features, including bulk-capacitor brown-in/brown-out protection, VDD over-voltage protection (VDD OVP), output over-voltage/under-voltage protection (Output OVP/UVP), secondary rectifier short-circuit protection (SRSP), and external over-temperature protection (External OTP); (3) For constant output power regulation, a resistor connected to CS pin can be used to achieve accurate line compensation across the universal input voltage range; and (4) The RT7755xE also provides various features to protect against any failures occurring at the secondary-side component, such as the RT7206 or a shunt regulator.
In applications, it is suggested that the RT7755xE be used with a secondary controller RT7206 to realize a robust and safe design to prevent all potential fault conditions due to misconnection of various devices, cables, plugs and receptacles.
- USB PD and Programmable Power Adapters