The RT6217E is a simple, easy-to-use, 3A synchronous step-down DC-DC converter with an input supply voltage range of 4.5V to 24V. The device build-in an accurate 0.791V reference voltage and integrates low RDS(ON) power MOSFETs to achieve high efficiency in a TSOT-23-8 (FC) package.

The RT6217E 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 RT6217E has MODE Selection function. To connect MODE pin to ground to force the RT6217E into Pulse Skipping Mode for light load efficiency improvement. Pulling the MODE pin high (i.e. > 2V) will force the RT6217E into CCM that helps meet tight voltage regulation accuracy requirements.

The RT6217E senses both FETs current for a robust over-current protection. It features cycle-by-cycle current limit protection and prevent the device from the catastrophic damage in output short circuit, over current or inductor saturation. An internally soft-start function prevents inrush current during start-up. 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 RT6217E is offered in a TSOT-23-8 (FC) package.


  • Set Top Box
  • Portable TV
  • Access Point Router
  • DSL Modem
  • LCD TV
Key Spec.
Status Active
Vin (min) (V) 4.5
Vin (max) (V) 24
Number of Outputs 1
Vout (min) (V) 0.791
Vout (max) (V) 6
Output Adj. Method Resistor
Iout (max) (A) 3
Current Limit (typ) (A) 4.2
Freq (typ) (kHz) 500
Ext Sync No
Ron_HS (typ) (mOhm) 85
Ron_LS (typ) (mOhm) 40
Iq (typ) (mA) 0.15
Features ACOT Control;COT Control;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;Internal Compensation;OCP;OTP;Selectable (PSM or PWM);Stable with Ceramic Capacitor;UVP
Package Type TSOT-28(FC)
  • 3A Converter With Built-in 85mΩ/40mΩ Low RDS(ON) Power FETs
  • Input Supply Voltage Range : 4.5V to 24V
  • Output Voltage Range : 0.791V to 6V
  • Advanced Constant On-Time (ACOTTM) Control
  • Ultrafast Transient Response
  • No Needs For External Compensations
  • Optimized for Low-ESR Ceramic Output Capacitors
  • 0.791V ±1.5% High-Accuracy Feedback Reference Voltage
  • Low Quiescent Current (150μA typ.)
  • Both HS/LS FETs Protection for Robust Over-Current Protection
  • Selectable Power Saving Mode (PSM) or Force PWM Mode
  • Light-load VOUT Ripple Reduction Technology in PSM
  • Steady Switching Frequency (500kHz typ.)
  • Internally Soft-Start Function (1500μs typ.)
  • Monotonic Start-up for Pre-biased Output
  • Input Under-Voltage Lockout (UVLO)
  • Output Under-Voltage Protection (UVP) with Hiccup Mode
  • Over-Temperature Protection (OTP) (Thermal Shutdown)
  • Enable Control
  • RoHS Compliant and Halogen Free
  • Available In TSOT-23-8 (FC) Package
TitleLast UpdateDownload
24V, 3A, 500kHz, ACOTTM Step-Down Converter in 8 Pin TSOT-232018/05/22
Reference Design
TitleLast UpdateDownload
Richtek Load Transient Tool2022/07/25
Part NumberPackage TypePackage Qty.Free SampleBuy From Authorized Distributor
RT6217EHGJ8FTSOT-28(FC)3000 Request Buy from Distributor