The RT2856 is a high efficiency, monolithic synchronous step-down DC-DC converter that can deliver up to 6A output current from a 4.5V to 18V input supply. The RT2856 current-mode architecture with external compensation allows the transient response to be optimized over a wide range of loads and output capacitors. Cycle-by-cycle current limit provides protection against shorted outputs and soft-start eliminates input current surge during start-up. Fault condition protections include output under-voltage protection, output over-voltage protection, and over-temperature protection. The low current shutdown mode provides output disconnection, enabling easy power management in battery-powered systems.


  • High Performance Point of Load Regulation
  • Notebook Computers
  • High Density and Distributed Power Systems
Key Spec.
Status Active
Vin (min) (V) 4.5
Vin (max) (V) 18
Number of Outputs 1
Vout (min) (V) 0.8
Vout (max) (V) 15
Output Adj. Method Resistor
Iout (max) (A) 6
Current Limit (typ) (A) 11
Freq (typ) (kHz) 480
Freq (min) (kHz) 200
Freq (max) (kHz) 1600
Ext Sync Yes
Ron_HS (typ) (mOhm) 26
Ron_LS (typ) (mOhm) 19
Iq (typ) (mA) 0.6
Features 100% Duty Cycle;Adjustable Frequency;Adjustable Soft-Start;Current Mode Control;Cycle-by-Cycle Current Limit;Enable Input;External Synchronization;Force PWM;OCP;OTP;Power Good;Stable with Ceramic Capacitor;UVP
Package Type WQFN3.5x3.5-14A
  • Low RDS(ON) Power MOSFET Switches 26mΩ/19mΩ
  • Input Voltage Range : 4.5V to 18V
  • Adjustable Switching Frequency : 200kHz to 1.6MHz
  • Current-Mode Control
  • Synchronous to External Clock : 200kHz to 1.6MHz
  • Accurate Voltage Reference 0.8V ± 1%, Over -40°C to 85°C
  • Monotonic Start-Up into Pre-biased Outputs
  • Adjustable Soft-Start
  • Power Good Indicator
  • Under-Voltage and Over-Voltage Protection
  • Input Under-Voltage Lockout
  • RoHS Compliant and Halogen Free
TitleLast UpdateDownload
6A, 18V, Synchronous Step-Down Converter2013/08/16
Reference Design
TitleLast UpdateDownload
Richtek Load Transient Tool2022/07/25
Part NumberPackage TypePackage Qty.Free SampleBuy From Authorized Distributor
RT2856GQWWQFN3.5x3.5-14A1500 Request Buy from Distributor