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The RT6338 family are high efficiency synchronous step-down DC-DC converters with pseudo constant switching frequency 500kHz and deliver up to 8A output current. The RT6338A/B and RT6338AH/BH operate from 4.5V to 23V input voltage. The output voltage of RT6338A/AH is programmed between 0.6V to 5.5V and RT6338B/BH is fixed to 3.3V output voltage. The input voltage of RT6338C/CH ranges from 5.2V to 23V and the output voltage of RT6338C/CH is fixed to 5.1V.

The RT6338 adopts Advanced Constant On-Time (ACOT®) control architecture that provides ultra-fast transient response and further reduces the external component count. In steady states, the ACOTV® operates at nearly constant switching frequency over line, load and output voltage ranges and makes the EMI filter design easier.

By setting the voltage of the EN/MODE pin, RT6338 operates either in diode emulation mode (DEM) or ultrasonic mode (USM) at light load. The USM maintains operation frequency above 25kHz, which eliminates the acoustic noise. In the DEM, RT6338 provides the best light-load efficiency and improves the acoustic noise with spread spectrum function.

RT6338 provides PGOOD indicator for easy system sequence control. Full protection features are also integrated in the device, including the cycle-by-cycle current limit, OVP, UVP, input UVLO and OTP.

All above functions are integrated in a UQFN-23L 3x3 (FC) package.

Applications

  • Laptop Computers
  • Tablet PCs
  • Networking Systems
  • Servers
  • Personal Video Recorders
  • Flat Panel Television and Monitors
  • Distributed Power Systems
Key Spec.
RT6338A RT6338B RT6338C
Status Active Active Active
Vin (min) (V) 4.5 4.5 5.2
Vin (max) (V) 23 23 23
Number of Outputs 1 1 1
Vout (min) (V) 0.6 3.267 5.049
Vout (max) (V) 5.5 3.333 5.151
Output Adj. Method Resistor Fixed Fixed
Iout (max) (A) 8 8 8
Current Limit (typ) (A) 10;12;14 12 12
Freq (typ) (kHz) 500 500 500
Ext Sync No No No
Ron_HS (typ) (mOhm) 26 26 26
Ron_LS (typ) (mOhm) 14 14 14
Iq (typ) (mA) 0.085 0.095 0.095
Features ACOT Control;Adjustable Current Limit;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;Internal Compensation;OCP;OTP;OVP;PSM;Power Good;Stable with Ceramic Capacitor;UVP ACOT Control;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;Internal Compensation;OCP;OTP;OVP;PSM;Power Good;Stable with Ceramic Capacitor;UVP ACOT Control;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;Internal Compensation;OCP;OTP;OVP;PSM;Power Good;Stable with Ceramic Capacitor;UVP
Package Type UQFN3x3-23(FC) UQFN3x3-23(FC) UQFN3x3-23(FC)
Features
  • Input Voltage Range
    ► RT6338A/B and RT6338AH/BH : 4.5V to 23V
    ► RT6338C/CH : 5.2V to 23V
  • Output Voltage
    ► RT6338A/AH : 0.6V to 5.5V
    ► RT6338B/BH : 3.3V
    ► RT6338C/CH : 5.1V
  • 8A Continuous Output Current
  • Stable with POSCAP and MLCC Capacitor
  • Fast Transient Response
  • Diode Emulation Mode (DEM) for Power Saving
  • Ultrasonic Mode (USM) for Avoiding Acoustic Noise
  • Pseudo Constant Switching Frequency 500kHz in CCM
  • Internal Power MOSFET Switch 26mΩ (high-side) and 14mΩ (low-side)
  • LDO
    ► RT6338B/BH : 3.3V/100mA
    ► RT6338C/CH : 5V/100mA
  • Over-Current Limit
    ► RT6338A/AH : Adjustable (10A, 12A or 14A)
    ► RT6338B/BH/C/CH : 12A
  • Output Under-/Over-Voltage Protection (UVP/OVP)
    ► RT6338A/B/C : Latched Mode UVP/OVP
    ► RT6338AH/BH/CH : Hiccup Mode UVP and Non-Latched Mode OVP
  • Input Under-Voltage Lockout (UVLO)
  • Over-Temperature Protection (OTP)
    ► RT6338A/B/C : Latched Mode OTP
    ► RT6338AH/BH/CH : Non-Latched Mode OTP
Datasheet
TitleLast UpdateDownload
8A, 23V Synchronous Step-Down Converter with 3.3V/5V LDO2021/10/13
Technical Documents
TitleItem TypeLast UpdateDownload
Richtek Product Selection Guide [Jan., 2024] Selection Guide2024/01/18
Richtek Featured Product Tree [Aug., 2023] Selection Guide2023/08/07
Reference Design
TitleLast UpdateDownload
Richtek Load Transient Tool2022/07/25
Part NumberPackage TypePackage Qty.Free SampleBuy From Authorized Distributor
RT6338AHGQUFUQFN3x3-23(FC)1500 Request Buy from Distributor
RT6338BGQUFUQFN3x3-23(FC)1500 Request Buy from Distributor
RT6338BHGQUFUQFN3x3-23(FC)1500 Request Buy from Distributor
RT6338CGQUFUQFN3x3-23(FC)1500 Request Buy from Distributor
RT6338CHGQUFUQFN3x3-23(FC)1500 Request Buy from Distributor
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