5.5VIN, 2A, High Efficiency Synchronous Step-Down Converter with Low Quiescent Current


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The RT5715 is a 2A, high-efficiency, Advanced Constant-On-Time (ACOT) synchronous step-down converter. The device operates with input voltages from 2.5V to 5.5V. The device can program the output voltage between 0.45V to VIN. The low quiescent current design with the integrated low RDS(ON) power MOSFETs achieves high efficiency over the wide load range. The advanced COT operation allows transient responses to be optimized over a wide range of loads, and output capacitors to efficiently reduce external component count. The RT5715 provides up to 2.7MHz switching frequency to minimize the size of output inductor and capacitors.

The RT5715 provides complete protection functions such as input under voltage lockout, output under voltage protection, over current protection, and thermal shutdown.

Cycle-by-cycle current limit provides protection against shorted outputs and soft-start eliminates input current surge during start-up. The RT5715 is available in WDFN-8SL 2x2 package.


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Key Spec.
Status Active
Vin (min) (V) 2.5
Vin (max) (V) 5.5
Number of Outputs 1
Vout (min) (V) 0.45
Vout (max) (V) 3.3
Output Adj. Method Resistor
Iout (max) (A) 2
Current Limit (typ) (A) 3.2
Freq (typ) (kHz) 2700
Ext Sync No
Ron_HS (typ) (mOhm) 100
Ron_LS (typ) (mOhm) 80
Iq (typ) (mA) 0.03
Features 100% Duty Cycle;ACOT Control;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;Internal Compensation;OCP;OTP;PSM;Power Good;Stable with Ceramic Capacitor;UVP
Package Type WDFN2x2-8S
  • 2A Converter Integrated 100mΩ and 80mΩ FETs in WDFN-8SL 2x2 Package
  • Input Supply Voltage Range : 2.5V to 5.5V
  • Output Voltage Range : 0.45V to VIN
  • Advanced Constant On-Time (ACOTTM) Control
    ► Ultrafast Transient Response
    ► No Needs for External Compensations
    ► Optimized for Low-ESR Ceramic Output Capacitors
  • High Accuracy Feedback Reference Voltage : 0.45V ± 1%
  • Low Quiescent Current : 30μA
  • Fixed Switching Frequency : 2.7MHz
  • Internally Fixed Soft-Start (typ. 150μs)
  • Safe Start-Up from Pre-biased Output
  • Input Under-Voltage Lockout (UVLO)
  • Output Under-Voltage Protection (UVP) with Hiccup Mode
  • Over-Temperature Protection (OTP) (Thermal Shutdown)
  • Enable Control
  • Power Good Indication
  • RoHS Compliant and Halogen Free
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5.5VIN, 2A, High Efficiency Synchronous Step-Down Converter with Low Quiescent Current2015/12/24
Technical Documents
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Richtek Selection Guide [Oct., 2020]2020/12/30
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Reference Design
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Design Tool
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Richtek Designer™ Web Simulation Tool : RT5715GQW2020/09/23