The RT6214A/B is a simple, easy-to-use, 3A synchronous step-down DC-DC converter with an input supply voltage range of 4.5V to 18V. The device integrates low RDS(ON) power MOSFETs to achieve high efficiency in a SOT-23 package and build-in accurate reference voltage (0.765V or 0.8V by product options).

The RT6214A/B adopts Advanced Constant On-Time (ACOT®) control architecture to provide an ultrafast transient response with few external components and to operate in nearly constant switching frequency over the line, load, and output voltage range. The RT6214A operates in automatic PSM that maintains high efficiency during light load operation. RT6214B operates in Forced PWM that helps meet tight voltage regulation accuracy requirements.

The RT6214A/B senses both FETs current for a robust over-current protection. The device features cycle-by-cycle current limit protection and prevent the device from the catastrophic damage in output short circuit, over current or inductor saturation. The RT6214A/B SOT-23-6 series built-in soft-start function prevents inrush current during start-up and the SOT-23-8 series offers programmable start-up by connecting a capacitor at external SS pin. The device also includes input under-voltage lockout, output under-voltage protection, and over-temperature protection (thermal shutdown) to provide safe and smooth operation in all operating conditions. The RT6214A/B are offered in TSOT-23-6 (FC) and TSOT-23-8 (FC) package.


  • Set-Top Boxes
  • LCD TVs
  • Home Networking Devices
  • Surveillance
  • General Purpose
Key Spec.
RT6214A RT6214B
Status Active Active
Vin (min) (V) 4.5 4.5
Vin (max) (V) 18 18
Number of Outputs 1 1
Vout (min) (V) 0.765;0.8 0.765;0.8
Vout (max) (V) 6.5 6.5
Output Adj. Method Resistor Resistor
Iout (max) (A) 3 3
Current Limit (typ) (A) 4.5 4.5
Freq (typ) (kHz) 500;650 500;650
Ext Sync No No
Ron_HS (typ) (mOhm) 100 100
Ron_LS (typ) (mOhm) 50 50
Iq (typ) (mA) 0.5 0.5
Features ACOT Control;COT Control;Enable Input;Internal Compensation;OCP;OTP;PSM;UVP ACOT Control;COT Control;Enable Input;Internal Compensation;OCP;OTP;UVP
Package Type TSOT-26(FC);TSOT-28(FC) TSOT-26(FC);TSOT-28(FC)
  • Input Supply Voltage Range : 4.5V to 18V
  • 3A Converter With Built-in 100mΩ/50mΩ Low RDS(ON) Power FETs
  • Advanced Constant On-Time (ACOTTM) Control for Ultrafast Transient Response
  • Fixed Switching Frequency : 500kHz (SOT23-6) or 650kHz (SOT23-8)
  • Optional for Operation Modes :
    ► Automatically Power Saving Mode (PSM) (RT6214A)
    ► Forced PWM Mode (RT6214B)
  • Optimized for Low-ESR Ceramic Output Capacitors
  • ±1.5% High-Accuracy Feedback Reference Voltage
  • Output Voltage Range : up to 6.5V
  • Internal fixed Soft-Start (typ. 1ms) for SOT-23-6
  • Externally Adjustable Soft-Start for SOT-23-8
  • Monotonic Start-Up for Pre-biased Outputs
  • Both HS/LS FETs Protection for Robust Over Current Protection
  • Input Under-Voltage Lockout (UVLO)
  • Output Under-Voltage Protection (UVP) with Hiccup Mode
  • Over-Temperature Protection (OTP) (Thermal Shutdown)
  • Enable Control
  • Power Good Indication for SOT-23-8
  • RoHS Compliant and Halogen Free
  • Available in TSOT-23-6 or TSOT-23-8 Package
TitleLast UpdateDownload
18V, 3A, ACOTTM Step-Down Converter in 6 and 8 Pin TSOT-232017/10/30
Reference Design
TitleLast UpdateDownload
Richtek Load Transient Tool2022/07/25
Part NumberPackage TypePackage Qty.Free SampleBuy From Authorized Distributor
RT6214AHGJ6FTSOT-26(FC)3000 Request Buy from Distributor
RT6214AHRGJ6FTSOT-26(FC)3000 Request Buy from Distributor
RT6214AHRGJ8FTSOT-28(FC)3000 Request Buy from Distributor
RT6214BHGJ6FTSOT-26(FC)3000 Request Buy from Distributor
RT6214BHRGJ6FTSOT-26(FC)3000 Request Buy from Distributor
RT6214BHRGJ8FTSOT-28(FC)3000 Request Buy from Distributor