6A, 23V, 500kHz, ACOT® Synchronous Buck Converter


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The RT6220 is a synchronous Buck converter with Advanced Constant On-Time (ACOT® ) mode control, which provides a very fast transient response with no external compensators. The RT6220 operates from 4.5V to 23V input voltage, provides complete protection functions including Over Current Protection (OCP), Under Voltage Protection (UVP) and Over Voltage Protection (OVP). This IC also provides a 1.5ms internal soft-start function and an open-drain power good indicator.


  • Laptop Computers
  • Tablet PCs
  • Networking Systems
  • Servers
  • Personal Video Recorders
  • Flat Panel Television and Monitors
  • Distributed Power Systems
Key Spec.
RT6220A RT6220B
Status Active Active
Vin (min) (V) 4.5 4.5
Vin (max) (V) 23 23
Number of Outputs 1 1
Vout (min) (V) 0.6 0.6
Vout (max) (V) 5 5
Output Adj. Method Resistor Resistor
Iout (max) (A) 6 6
Freq (typ) (kHz) 500 500
Ext Sync No No
Ron_HS (typ) (mOhm) 31 31
Ron_LS (typ) (mOhm) 20 20
Iq (typ) (mA) 0.1 0.11
Features ACOT Control;Built-in Bootstrap Switch;Cycle-by-Cycle Current Limit;Diode Emulation Mode;Enable Input;Fast Transient Response;OCP;OVP;PSM;Power Good;Stable with Ceramic Capacitor;UVP ACOT Control;Built-in Bootstrap Switch;Cycle-by-Cycle Current Limit;Diode Emulation Mode;Enable Input;Fast Transient Response;Force PWM;OCP;OVP;Power Good;Stable with Ceramic Capacitor;UVP
Package Type UQFN3x3-16(FC) UQFN3x3-16(FC)
  • 4.5V to 23V Input Voltage Range
  • Adjustable from 0.6V to 5V Output Range
  • Up to 98% Duty for 2S Battery Application
  • 500kHz Switching Frequency
  • ACOT® Mode Performs Fast Transient Response
  • Integrated MOSFETs
    ► 31mΩ of High-Side MOSFET
    ► 20mΩ of Low-Side MOSFET
  • Supports MLCC Output Capacitors
  • Internal Soft-Start (1.5ms typ)
  • Built-in OVP/UVP/OCP
  • Power Good Indicator
  • Thermal Shutdown
TitleLast UpdateShareDownload
6A, 23V, 500kHz, ACOT® Synchronous Buck Converter2014/10/30
Technical Documents
TitleLast UpdateShareDownload
ACOT® Stability Testing2020/04/13
The Calculation of Output DC Offset for ACOT™ Control Buck Converter with Feed-forward Compensator2019/12/12
Richtek Wide Input Voltage Range DC/DC Power Solutions for Industrial, Automotive and LED lighting applications2019/12/12
ACOT™ (Advanced Constant-On Time) Synchronous Step-Down Converters2019/12/12
Comparing Buck Converter Topologies2019/12/12
Buck Converter Selection Criteria2019/12/12
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How to estimate control loop bandwidth from the transient response time?2017/03/30 802
Reference Design
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Richtek Load Transient Tool2019/01/09