The RT2659 in thermally enhanced VQFN-20L 3.5x4 package is a full featured 6V, 6A synchronous step-down DC-DC converter designed specifically for Double Data Rate (DDR) memory termination, which provides a continuous 6A sink and source current and fixed 1/2 DDQ at output. The current mode COT architecture with external compensation allows the transient response to be optimized over a wide range of loads and achieves nearly constant switching frequency over line, load, and output voltage ranges. The multiple sets of over-current limit and switching frequency offer an optimized power chain for application design.

Efficiency is maximized through the integrated 20mΩ/10mΩ MOSFETs, and cycle-by-cycle current limit provides protection against shorted outputs. Output external tracking function, output soft discharge, power good indicating, output droop support are all featured in the RT2659. In addition, the device is specified from 0°C to 105°C to perform an excellent regulation with an accurate 1% reference voltage over temperature.


  • DDR-2/3/4 VTT Regulation (1/2VDDQ) for Enterprise Servers, Ethernet Switches and Routers, Global Storage, GSM Base Station, and Industrial equipments
  • Enterprise POL (using precision internal VREF)
Key Spec.
Status Active
Vin (min) (V) 1
Vin (max) (V) 6
Number of Outputs 1
Vout (min) (V) 0.6
Vout (max) (V) 2
Output Adj. Method Ext Vref;Resistor
Iout (max) (A) 6
Current Limit (typ) (A) 5.4;7.6
Freq (typ) (kHz) 1000;600
Ext Sync No
Ron_HS (typ) (mOhm) 20
Ron_LS (typ) (mOhm) 10
Iq (typ) (mA) 1.1
Features Adjustable Current Limit;Adjustable Frequency;COT Control;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;OCP;OTP;OVP;PSM;Power Good;Selectable (PSM or PWM);Stable with Ceramic Capacitor;UVP
Package Type VQFN3.5x4-20
  • Continuous 6A Sink or Source Output Current ability and Droop Design for DDR Memory Termination Applications
  • Low RDS(ON) Power N-MOSFET Switches 20mΩ/10mΩ
  • Input Voltage Range : 1V to 6V
  • Output Adjustable from 0.6V to 2V
  • Current-Mode Constant On-Time Control Design Enables Fast Transient Response
  • Supports All MLCC Output Capacitor and SP/POSCAP with Robust Loop Stabilization
  • Selectable 600kHz or 1MHz Switching Frequency
  • Supports Pre-biased Start-Up
  • Selectable Over-Current Protection
  • Various Operation Mode Selection for Different Application Requirements
  • External Tracking Start-Up Application
  • Enable Input Control and Power Good Indicator
  • Under-Voltage and Over-Voltage Protection
TitleLast UpdateDownload
6A, 6V, Synchronous Step-Down Converter with REFIN2018/09/12
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
RT2659HGQVVQFN3.5x4-201500 Request Buy from Distributor