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The RT2857B is a high efficiency, monolithic synchronous step-down DC-DC converter that can deliver up to 6A output current from a 4.5V to 18V input supply. The RT2857B current-mode architecture with external compensation allows the transient response to be optimized over a wide range of loads and output capacitors. Cycle-by-cycle current limit provides protection against shorted outputs and soft-start eliminates input current surge during start-up. Fault condition protections include output over-current protection, output over-voltage protection, and over-temperature protection. The low current shutdown mode provides output disconnection, enabling easy power management in battery-powered systems.

Applications

  • High Performance Point of Load Regulation
  • Notebook Computers
  • High Density and Distributed Power Systems
Key Spec.
RT2857B
Status Active
Vin (min) (V) 4.5
Vin (max) (V) 18
Number of Outputs 1
Vout (min) (V) 0.6
Vout (max) (V) 15
Output Adj. Method Resistor
Iout (max) (A) 6
Current Limit (typ) (A) 11
Freq (typ) (kHz) 480
Freq (min) (kHz) 200
Freq (max) (kHz) 1600
Ext Sync Yes
Ron_HS (typ) (mOhm) 26
Ron_LS (typ) (mOhm) 19
Iq (typ) (mA) 0.6
Features 100% Duty Cycle;Adjustable Frequency;Adjustable Soft-Start;Current Mode Control;Cycle-by-Cycle Current Limit;Enable Input;External Synchronization;Force PWM;OCP;OTP;Power Good;Stable with Ceramic Capacitor;UVP
Package Type WQFN3.5x3.5-14A
Features
  • Low RDS(ON) Power MOSFET Switches 26mΩ/19mΩ
  • Input Voltage Range : 4.5V to 18V
  • Adjustable Switching Frequency : 200kHz to 1.6MHz
  • Current-Mode Control
  • Synchronous to External Clock : 200kHz to 1.6MHz
  • Accurate Voltage Reference 0.6V ± 1%, Over -40°C to 85°C
  • Monotonic Start-Up into Pre-biased Outputs
  • Adjustable Soft-Start
  • Power Good Indicator
  • Over-Current Protection
  • Over-Temperature and Over-Voltage Protection
  • Input Under-Voltage Lockout
  • RoHS Compliant and Halogen Free
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 SampleDistributorStockBuy From Authorized Distributor
RT2857BHGQWWQFN3.5x3.5-14A1,500 Request Digikey 1,476 Buy
Mouser 1,500 Buy
Please confirm with our distributor or sales representative for actual stock status.
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