General Description

The RT6338E/EH family are high efficiency

synchronous step-down DC-DC converters with pseudo

constant switching frequency 500kHz and deliver up to

8A output current. The RT6338E/EH operate from 4.5V

to 23V input voltage. The output voltage of

RT6338E/EH is fixed to 3.36V output voltage.

The RT6338E/EH 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 ACOT®

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,

RT6338E/EH 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, RT6338E/EH

provides the best light-load efficiency and improves the

acoustic noise with spread spectrum function.

RT6338E/EH provides PGOOD indicator for easy

system sequence control. Full protection features are

also integrated in the device, including the cycle-bycycle current limit, OVP, UVP, input UVLO and OTP.

All above functions are integrated in a UQFN-23L 3x3

(FC) package.

Features

⚫ Input Voltage Range

 RT6338E/EH: 4.5V to 23V

⚫ Output Voltage

 RT6338E/EH: 3.36V

⚫ 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 26m (high-side)

and 14m (low-side)

⚫ LDO

 RT6338E/EH: 3.3V/100mA

⚫ Overcurrent Limit

 RT6338E/EH: 12A

⚫ Output Under-/Overvoltage Protection (UVP/OVP)

 RT6338E: Latched Mode UVP/OVP

 RT6338EH: Hiccup Mode UVP and Non-Latched

Mode OVP

⚫ Input Undervoltage Lockout (UVLO)

⚫ Over-Temperature Protection (OTP)

 RT6338E: Latched Mode OTP

 RT6338EH: Non-Latched Mode OTP

Applications

⚫ Laptop Computers

⚫ Tablet PCs

⚫ Networking Systems

⚫ Servers

⚫ Personal Video Recorders

⚫ Flat Panel Television and Monitors

⚫ Distributed Power Systems