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The RT7231/32/33/34 is a synchronous step-down DC/DC converter with Advanced Constant On-Time (ACOT®) mode control. It achieves high power density to deliver up to 4A output current from a 4.5V to 18V input supply. The proprietary ACOT® mode offers an optimal transient response over a wide range of loads and all kinds of ceramic capacitors, which allows the device to adopt very low ESR output capacitor for ensuring performance stabilization. In addition, RT7231/32/33/34 keeps an excellent constant switching frequency under line and load variation and the integrated synchronous power switches with the ACOT® mode operation provides high efficiency in whole output current load range. Cycle-by-cycle current limit provides an accurate protection by a valley detection of low side MOSFET and external soft-start setting eliminates input current surge during startup. Protection functions include thermal shutdown for RT7231/32/33/34, output Under Voltage Protection (UVP) / Over Voltage Protection (OVP) for RT7231/32. When the UVP/OVP is triggered, the device will enter latch mode for TSSOP-14 (Exposed Pad), and hiccup mode for WDFN-10L 3x3.

The RT7231/32 are available in TSSOP-14 (Exposed Pad) and WDFN-10L 3x3 packages, and the RT7231 is operated in forced continuous conduction mode.

The RT7233/34 are available in the SOP-8 (Exposed Pad) package, and the RT7233 is operated in forced continuous conduction mode.

Applications

  • Industrial and Commercial Low Power Systems
  • Computer Peripherals
  • LCD Monitors and TVs
  • Green Electronics/Appliances
  • Point of Load Regulation for High-Performance DSPs, FPGAs, and ASICs
Key Spec.
RT7231 RT7232 RT7233 RT7234
Status Active Active Active Active
Vin (min) (V) 4.5 4.5 4.5 4.5
Vin (max) (V) 18 18 18 18
Number of Outputs 1 1 1 1
Vout (min) (V) 0.765 0.765 0.765 0.765
Vout (max) (V) 8 8 8 8
Output Adj. Method Resistor Resistor Resistor Resistor
Iout (max) (A) 4 4 4 4
Current Limit (typ) (A) 5.85 5.85 5.85 5.85
Freq (typ) (kHz) 650 650 650 650
Ext Sync No No No No
Ron_HS (typ) (mOhm) 120 120 120 120
Ron_LS (typ) (mOhm) 50 50 50 50
Iq (typ) (mA) 1 1 1 1
Features ACOT Control;Adjustable Soft-Start;COT Control;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;Force PWM;OCP;OTP;OVP;Power Good;Stable with Ceramic Capacitor;UVP ACOT Control;Adjustable Soft-Start;COT Control;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;OCP;OTP;OVP;PSM;Power Good;Stable with Ceramic Capacitor;UVP ACOT Control;Adjustable Soft-Start;COT Control;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;Force PWM;OCP;OTP;Stable with Ceramic Capacitor ACOT Control;Adjustable Soft-Start;COT Control;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;OCP;OTP;PSM;Stable with Ceramic Capacitor
Package Type TSSOP-14(PP);WDFN3x3-10 TSSOP-14(PP);WDFN3x3-10 PSOP-8 PSOP-8
Features
  • ACOT® Mode Enables Fast Transient Response
  • 4.5V to 18V Input Voltage Range
  • 4A Output Current
  • 50mΩ Internal Low Site N-MOSFET
  • Advanced Constant On-Time Control
  • Support All Ceramic Capacitors
  • Up to 95% Efficiency
  • 650kHz Switching Frequency at all Load Current (RT7231, RT7233)
  • Discontinuous Operating Mode at Light Load (RT7232, RT7234)
  • Adjustable Output Voltage from 0.765V to 8V
  • Adjustable Soft-Start
  • Cycle-by-Cycle Current Limit
  • Input Under Voltage Lockout
  • Thermal Shutdown
  • RoHS Compliant and Halogen Free
Datasheet
TitleLast UpdateDownload
4A, 18V, 650kHz, ACOT® Synchronous Step-Down Converter2017/08/31
Evaluation Boards
TitleLast UpdateDownload
RT7232GQW Evaluation Board2021/01/21
RT7231GQW Evaluation Board2021/01/21
Reference Design
TitleLast UpdateDownload
Richtek Load Transient Tool2022/07/25
Part NumberPackage TypePackage Qty.Free SampleBuy From Authorized Distributor
RT7231GCPTSSOP-14(PP)2500 Request Buy from Distributor
RT7231GQWWDFN3x3-101500 Request Buy from Distributor
RT7233GSPPSOP-82500 Request Buy from Distributor
RT7234GSPPSOP-82500 Request Buy from Distributor
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