RT9645

Description

The RT9645 is a combo regulator which is compliant to ACPI specification for desktop/server power management and system application. The part features one switching regulator for DDR memory VDDQ power; a second PWM controller for GMCH core power, a LDO controller for FSB_ VTT termination, a LDO controller for 5VSB to 3VSB conversion; and a dual power control 5VDL for S0 and S3 system power.
The part is generally operated to conform to ACPI specification. In S3 mode, only VDDQ and 3.3VSB regulators remain on while the FSB_ VTT regulator is off. In the transition from S3 to S0, an internal SS capacitor is attached for linear regulators to control its slew rate respectively to avoid inrush current induced.
RT9645 supports both Intel VR11 and AMD K8 platform. There is extra control pin VTT_EN to enable FSB_VTT regulator at AMD K8 mode. This part also implements PWM1 (V_DDQ) enabled by release COMP1 at AMD K8 application. This part is assemblyed in the tiny VQFN-24L 4x4 package.