General Description

The RT3678BE is a synchronous buck controller which supports dual output rails and can fully meet AMD SVI3 requirements. The RT3678BE adopts G-NAVPTM (Green Native AVP), which is Richtek’s proprietary topology derived from finite DC gain of EA amplifier with current mode control, making it easy to set the droop to meet all AMD CPU/GPU requirements of AVP (Adaptive Voltage Positioning). Based on the G-NAVPTM topology, the RT3678BE features a new generation of quick response mechanism (Adaptive Quick Response, AQR) to optimize AVP performance during load transient and reduce output capacitors. The RT3678BE integrates a high accuracy ADC for reporting and a non-volatile memory (NVM) to store custom configurations, such as output current scale, auto phase add/drop threshold, switching frequency, overcurrent threshold or AQR trigger level. It also features full fault protection functions, including overvoltage (OV), undervoltage (UV), overcurrent (OC) and undervoltage lockout (UVLO), over-temperature protection (OTP), VR-hot warning, CRC failure and communication failure. The RT3678BE provides independent enable, power good and temperature sensing for each output rail. It also supports several functions which can be set by the I2C interface.

Applications

 AMD SVI3 VDDCR/VDDCR_SOC Rails

 Desktop and Notebook Computer

 AVP Step-Down Converter

Features

 AMD SVI3 Rev 1.01 Compatible

 8 Phase (Rail A) + 2 Phase (Rail B) PWM Controller

 G-NAVPTM (Green Native Adaptive Voltage Positioning) Topology

 0.5 DAC Accuracy

 Differential Remote Voltage Sensing

 Built-in ADC for Reporting

 Accurate Current Balance

 Diode Emulation Mode (DEM) at Light Load

 Fast Transient Response: Adaptive Quick Response (AQR)

 OVP, OCP and UVP with Flag

 Switching Frequency Setting

 Auto Phase Add/Drop with DEM for Excellent Efficiency

 Voltage On-the-Fly (VOTF) Enhancement

 Acoustic Noise Suppression

 Zero Load-line

 Standard I2C Protocol Interface

 Internal Non-Volatile Memory (NVM) to Store

Custom Configurations

 Current Balance Gain Adjustment for Thermal Balance

 Dynamic Load-line Setting

 Voltage Offset Setting

 Fixed VID Setting

 Protection Report and Protection Disable

 Output Voltage / Output Current / Temperature / Input Power Monitoring

 Soldering Good Detection

 Small 68-Lead WQFN Package