The RT8899A is a 3 + 2 phases PWM controller, and is compliant with AMD SVI2 GPU Specification to support both GPU core power (VDDC) and I/O bus (VDDCI). The RT8899A features CCRCOT (Constant Current Ripple Constant On-Time) with G-NAVP (Green-Native AVP), which is Richtek's proprietary topology. The G-NAVP makes it an easy setting controller to meet all AMD AVP (Adaptive Voltage Positioning) VDDC/VDDCI requirements. The droop is easily programmed by setting the DC gain of the error amplifier. With proper compensation, the load transient response can achieve optimized AVP performance. The controller also uses the interface to issue VOTF Complete and to send digitally encoded voltage and current values for the VDDC and VDDCI domains. It can operate in single phase and diode emulation mode and reach up to 90% efficiency in different modes according to different loading conditions. The RT8899A provides special purpose offset capabilities by pin setting. The RT8899A also provides power good indication, over-current indication (OCP_L) and dual OCP mechanism for AMD SVI2 GPU core power (VDDC) and I/O bus (VDDCI). It also features complete fault protection functions including over-voltage, under-voltage and negative-voltage protections.
Applications
- AMD SVI2 GPU Core Power
- Laptop Computer