24V, 3A, 500kHz, ACOTTM Step-Down Converter in 8 Pin TSOT-23


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The RT6217A/B 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 RT6217A/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 RT6217A operates in automatic PSM that maintains high efficiency during light load operation. The RT6217B operates in Forced PWM that helps meet tight voltage regulation accuracy requirements.

The RT6217A/B 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 externally adjustable 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 RT6217A/B is offered in a TSOT-23-8(FC) package.


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Key Spec.
RT6217A RT6217B
Status Active Active
Vin (min) (V) 4.5 4.5
Vin (max) (V) 24 24
Number of Outputs 1 1
Vout (min) (V) 0.791 0.791
Vout (max) (V) 6 6
Output Adj. Method Resistor Resistor
Iout (max) (A) 3 3
Current Limit (typ) (A) 4.2 4.2
Freq (typ) (kHz) 500 500
Ext Sync No No
Ron_HS (typ) (mOhm) 85 85
Ron_LS (typ) (mOhm) 40 40
Iq (typ) (mA) 0.15 0.15
Features ACOT Control;Adjustable Soft-Start;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;PSM;Power Good;UVP ACOT Control;Adjustable Soft-Start;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;Force PWM;Power Good;UVP
Package Type TSOT-28(FC) 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
  • Optional for Operation Modes :
    ► Power Saving Mode (PSM) at Light Load (RT6217A)
    ► Forced PWM Mode (RT6217B)
  • Light-load VOUT Ripple Reduction Technology in PSM
  • Steady Switching Frequency (500kHz typ.)
  • Externally Adjustable Soft-Start
  • 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)
  • Power Good Indication
  • Enable Control
  • RoHS Compliant and Halogen Free
  • Available In TSOT-23-8 (FC) Package
TitleLast UpdateShareDownload
24V, 3A, 500kHz, ACOTTM Step-Down Converter in 8 Pin TSOT-232018/01/11
Reference Design
TitleLast UpdateShareDownload
Richtek Load Transient Tool2019/01/09
Part NumberPackage TypePackage Qty.Free SampleBuy From Authorized Distributor
RT6217BHGJ8FTSOT-28(FC)3000 Request Buy from Distributor