AGREE

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RT7235/RT7236/RT7239/RT7240

5A, 18V, 650kHz, ACOT® Synchronous Step-Down Converter

RT7235/RT7236/RT7239/RT7240
New

The RT7235/36/39/40 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 5A 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, RT7235/36/39/40 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 detection of low-side MOSFET and external soft-start setting eliminates input current surge during startup. Protection functions include thermal shutdown for RT7235/36/39/40, output under-voltage protection (UVP) / over-voltage protection (OVP) for RT7235/36. 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 RT7235/36 are available in TSSOP-14 (Exposed Pad) and WDFN-10L 3x3 packages, and the RT7235 is operated in forced continuous conduction mode.

The RT7239/40 are available in the SOP-8 (Exposed Pad) package, and the RT7239 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.

RT7235 RT7236 RT7239 RT7240
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) 5 5 5 5
Current Limit (typ) (A) 6.85 6.85 6.85 6.85
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) 35 35 35 35
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

  • 5A Output Current

  • 35mΩ 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 (RT7235, RT7239)

  • Discontinuous Operating Mode at Light Load (RT7236, RT7240)

  • Adjustable Output Voltage from 0.765V to 8V

  • Adjustable Soft-Start

  • Cycle-by-Cycle Current Limit

  • Output Over- and Under-voltage Shut Down (RT7235, RT7236)

  • Input Under Voltage Lockout

  • Thermal Shutdown

  • RoHS Compliant and Halogen Free

Application Notes

Datasheet

DS7235_36_39_40-12.pdf

Videos

How to estimate control loop bandwidth from the transient response time?
Introduction to Richtek's Advanced Constant On Time Buck Converters

Datasheet

DS7235_36_39_40-12.pdf

RT7235GQW
Package Type:WDFN3x3-10
Sample Buy
RT7236GCP
Package Type:TSSOP-14(PP)
Sample Buy
RT7236GQW
Package Type:WDFN3x3-10
Sample Buy
RT7239GSP
Package Type:PSOP-8
Sample Buy
RT7240GSP
Package Type:PSOP-8
Sample Buy

Evaluation Boards

EVB_RT7235GQW
Buy
EVB_RT7236GQW
Buy
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