loading

The RT8800A is a general-purposed multi-phase synchronous buck controller dedicating for high power density applications. The RT8800A operates with 2 or 3 synchronous buck switching stages in interleaved phase set automatically. The multiphase architecture provides high output current while maintaining low power dissipation on power devices and low stress on input and output capacitors.

The output voltage is precisely regulated to the external reference voltage at PI pin. The RT8800A can provide Intel® VRD10.x or AMD® K8 compliant output voltage when companioned with DAC generator RT9401A/B.

The RT8800A adopts innovative time-sharing DCR current sensing technique for channel current balance, droop tuning, and over current protection. Using one common GM amplifier for current sensing eliminates offset errors and linearity variation between GMs. As sub-milli-ohm-grade inductors are widely used in modern mother boards, slight mismatch of GM amplifiers offset and linearity results in considerable current shift between phases. The time-sharing DCR current sensing technique is extremely important to guarantee phase current balance at mass production.

Other features include overvoltage protection, undervoltage protection and internal softstart. The RT8800A comes to a VQFN-16L 3x3 package.

Applications

  • Desktop CPU Core Power
  • Low Output Voltage, High Power Density DC/DC Converters
  • Voltage Regulator Modules
Key Spec.
RT8800A
Status Active
VID Table Support K8;VR10
Number of Phases 3
Vcc (typ) (V) 5
Vin (min) (V) 10.8
Vin (max) (V) 13.2
Accuracy (Vout>=1V) (+/- %) 1.25
Freq (typ) (kHz) 300
Built-in DAC Generator Yes
Number of MOSFET Drivers 0
Features Adjustable Frequency;DCR Current Sense;Droop Control;OCP;OVP;Power Good;SCP;Voltage Mode Control
Package Type VQFN3x3-16
Features
  • 5V Power Supply Voltage
  • 2/3-Phase Power Conversion with Automatic Phase Selection
  • Output Voltage Controlled by External Reference Voltage
  • Precise Core Voltage Regulation
  • Power Stage Thermal Balance by DCR Current Sensing
  • Extreme Low-Cost, Lossless Time Sharing Current Sensing
  • Internal Soft-Start
  • Hiccup Mode Over-Current Protection
  • Over Voltage Protection
  • Adjustable Operating Frequency and Typical at 300kHz Per Phase
  • Power Good Indication
  • Small 16-Lead VQFN Package
  • RoHS Compliant and 100% Lead (Pb)-Free
Datasheet
TitleLast UpdateDownload
General Purpose 3-Phase PWM Controller for High-Density Power Supply2015/05/19
TOP