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The RT8127A is a high efficiency Dual-Channel output synchronous Buck PWM controller with integrated MOSFET drivers and two LDOs. This part features Green Voltage Mode (GVMTM) control, which is specifically designed to improve efficiency at light load condition. At light load condition, the RT8127A is pin configurable to automatically operate in diode emulation mode with constant on-time PFM to reduce switching frequency so as to improve conversion efficiency. As the load current increases, the RT8127A leaves the diode emulation mode and operates in Continuous Conduction Mode (CCM) with fixed-frequency, 180° out of phase interleaved PWM to reduce input capacitance. The RT8127A supports 4.5V to 26V input voltage range and has integrated 5V LDO which supplies the internal gate drivers as well as the controller. When channel 1 Buck regulator output voltage is higher than 5V, the supply voltage will be automatically switched to the Buck regulator output from the integrated 5V LDO. The RT8127A supports enable/disable function for each channel and also features external soft-start, adjustable switching frequency and power good indication. This device utilizes lossless inductor DCR current sensing for over current protection. Other protections include over voltage, under voltage, thermal shutdown and under voltage lockout.

The RT8127A is available in a WQFN-28L 4x4 small footprint package.

Applications

  • Motherboard, Server, Graphic Card
  • System Power Supplies
  • Power Module
Key Spec.
RT8127A
Status Active
Vs (typ) (V) 5
Vin (min) (V) 4.5
Vin (max) (V) 26
Vout (min) (V) 0.8
Vout (max) (V) 5
Output Adj. Method Resistor
Accuracy (+/- %) 1
Freq (typ) (kHz) 300;350;400;600
Iq (typ) (mA) 2
Ext Sync No
Features Adjustable Frequency;Adjustable Soft-Start;Built-in Bootstrap Switch;Diode Emulation Mode;Enable Input;Low Dropout;OCP;OVP;Power Good;Selectable (PSM or PWM);UVP;Ultrasonic Mode Control;Voltage Mode Control
Package Type WQFN4x4-28
Features
  • Green Voltage Mode (GVMTM) Control
  • High Light Load Efficiency
  • Audio-Skip Mode (ASM) at Light Load
  • Pin Configurable CCM/DEM Operation
  • 180° Interleaving PWM in CCM Operation
  • Support 4.5V to 26V Input Voltage Range
  • Integrated 5V MOSFET Driver and Bootstrap Circuit
  • Integrated 5V and 12V LDO
  • Enable Control for Each Channel
  • External/Internal Soft-Start
  • Programmable LGATE PWM Frequency Setting (LGFS)
  • Automatic Switchable 5V Regulator
  • Power Good Indication
  • VIN Feed-Forward in Control Loop
  • Lossless DCR Current Sensing
  • OVP, UVP, OCP, Thermal Shutdown and UVLO
  • RoHS Compliant and Halogen Free
Datasheet
TitleLast UpdateDownload
High Efficiency Dual-Channel Output Synchronous Buck PWM Controller with Phase Interleaving and Two LDO Regulators2014/01/22
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