The RT8809A/B is a dual-phase synchronous buck PWM controller with integrated drivers which are optimized for high performance graphic microprocessor and computer applications. The IC integrates a G-NAVPTM PWM controller, two 12V MOSFET drivers with internal bootstrap diodes, as well as output current monitoring and protection functions into the WQFN-24L 4x4 package. The RT8809A/B adopts DCR and RDS(ON) current sensing. Load line voltage positioning (droop) and over current protection are accomplished through continuous inductor DCR current sensing, while RDS(ON) current sensing is used for accurate channel current balance. Using both methods of current sampling utilizes the best advantages of each technique. The RT8809A/B also features a one-bit VID control operation in which the feedback voltage is regulated and tracks external input reference voltage. Other features include, adjustable operating frequency, external compensation, and enable/shutdown functions.
Feature
- Dual-Phase PWM Controller
- Two Embedded MOSFET Drivers and Embedded Switching Boot Diode
- Green-NAVPTM (Green Native Adaptive Voltage Positioning) Topology
- Dynamic Auto Phase Control with Programmable Threshold
- Cross-talk Jitter Suspend (CJSTM)
- Remote GND Detection for High Accuracy
- Automatic Diode Emulation Mode/Or Ultrasonic Mode at Light Load
- Lossless RDS(ON) Current Sensing for Current Balance
- Lossless DCR Current Sensing for AVP & OCP
- Reference Voltage Output with 1% Accuracy
- External Reference Input with Soft-Start (RISS)
- Embedded One-Bit VID Control
- Programmable OCP Threshold
- Programmable Switching Frequency
- Reference Tracking UVP/OVP Protection
- Shoot Through Protection and Short Pulse Free Technology
- RoHS Compliant and Halogen Free
Applications
- Middle to High End GPU Core Power
- High End Desktop PC Memory Core Power
- Low Voltage, High Current DC/DC Converter
- Voltage Regulator Modules
- Motherboards
