loading

The RT5757A is a high-performance, synchronous step-down DC-DC converter that can deliver up to 7A output current from a 3V to 6.5V input supply. The output voltage is programmable from 0.6V to 1.725V with I2C controlled 7-bit VID.

The device integrates low RDS(ON) power MOSFETs, accurate 0.6V reference and an integrated diode of bootstrap circuit to offer a very compact solution.

The RT5757A adopts Advanced Constant On-Time (ACOT®) control architecture that provides ultrafast 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. The RT5757A offers automatic PSM that maintains high efficiency during light load operation. The RT5757A can also operate in Forced-CCM through I2C setting that helps meet tight voltage regulation accuracy requirements.

The device offers a variety of functions for more design flexibility. The switching frequency, current limit level and over-temperature threshold are selectable via I2C. Independent enable control input pin and power good indicator are also provided for easy sequence control. Besides, the designer can also enable or shutdown the device via the I2C interface.

The device offers independent enable control input pin and power good indicator for easy sequence control. To control the inrush current during the startup, the device provides a programmable soft-start up by an external capacitor connected to the SS pin. Full protection features are also integrated in the device, including the cycle-by-cycle current limit control, UVP, input UVLO and OTP.

The RT5757A is available in a thermally enhanced UQFN-13L 3x3 (FC) package.

Applications

  • Mobile Phones and Handheld Devices
  • STB, Cable Modem, and xDSL Platform
  • WLAN ASIC Power / Storage (SSD and HDD)
  • General Purpose for POL LV Buck Converter
  • TV
Key Spec.
RT5757A
Status Active
Vin (min) (V) 3
Vin (max) (V) 6.5
Number of Outputs 1
Vout (min) (V) 0.6
Vout (max) (V) 1.725
Output Adj. Method Digital
Iout (max) (A) 7
Current Limit (typ) (A) 8;8.8;9.6
Freq (typ) (kHz) 1000;1500;600;800
Ext Sync No
Ron_HS (typ) (mOhm) 12
Ron_LS (typ) (mOhm) 8
Iq (typ) (mA) 0.1
Interface I2C
Features ACOT Control;Adjustable Current Limit;Adjustable Frequency;Adjustable Soft-Start;Built-in Bootstrap Switch;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;I2C;Internal Compensation;OCP;OTP;PSM;Power Good;Stable with Ceramic Capacitor;UVP
Package Type UQFN3x3-13(FC)
Features
  • Dramatically Fast Transient Response
  • Steady 1MHz ±20% Switching Frequency
  • Advanced COT Control Loop
  • Optimized for Ceramic Output Capacitors
  • 3V to 6.5V Input Voltage Range
  • Integrated 12mΩ/8mΩ MOSFETs
  • Internal Start-Up into Pre-Biased Outputs
  • Power Good Indicator
  • Enable Control
  • Over-Current and Over-Temperature Protections
  • Under-Voltage Protection with Hiccup Mode
  • VID Control Range Via I2C Compatible Interface : 0.6V to 1.725V step = 12.5mV
  • Junction Temperature Range : -40°C to 125°C
  • Ambient Temperature Range : -40°C to 85°C
Datasheet
TitleLast UpdateDownload
7A, 6.5V, 1MHz, ACOT® Synchronous Step-Down Converter with I2C Interface2023/03/29
TOP