RT8055GQW

RT8055GQW is a choice of cost-effective PWM DC/DC converters that provide high efficiency, low power dissipation and a high-level integration feature. It is designed to meet the requirements of portable applications, such as PDAs and notebook computers. It is a fully integrated low voltage CMOS switch DC-DC controller with dual output, which can also be used in a three-terminal adjustable controller solution.

The RT8055GQW is designed to operate with switching frequencies up to 2MHz, so it is well suited for low cost applications with power levels up to 1.4W. The device is capable of generating two output voltages (VOUT1 and VOUT2) from a single power supply. It is suitable for multiple output applications such as +5V and +3.3V in step-down and step-up configurations, making it ideal for notebook or PDA applications.

Features

• High efficiency up to 98%
• Two synchronous output
• Max 3A output current
• Shutdown, sleep, rising and falling modes
• Small package 10 pin QFN(1.7mmx2.2mmx0.6mm)
• Tiny PCB area(0.61in²)

Application fields

• PDAs
• Notebook computers
• Set-top boxes
• High end smart phones
• LCD monitors

Working principle

The RT8055GQW is a PWM current mode DC/DC converter. The regulation loop of the RT8055GQW contains an input feed-forward function and an output error amplifier. The input feed-forward operation is used to compensate for the input voltage variations in order to increase system stability and accuracy. The output error amplifier is used to minimize output oscillations, making the RT8055GQW an ideal choice for applications requiring precise output voltage regulation.

The device employs a constant frequency PWM current mode architecture. The peak current of the internal power MOSFETs is monitored by the current sense comparator. When the current sense threshold is reached, the power MOSFETs are shut off and the switching cycle is terminated. When the next switching cycle begins, the power MOSFETs are activated and the voltage is regulated again.

The RT8055GQW is designed with over-current protection (OCP) and pulse-by-pulse current limit. The OCP is triggered when the output current exceeds the trip threshold, and the device is immediately turned off. The pulse-by-pulse current limit protects the device from over-current conditions beyond the OCP threshold.