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RT7274/79/80/81 系列為ACOT(Advanced Constant On-Time)操作模式之同步整流降壓式直流轉換器,輸入電壓4.5V至18V範圍內,最大電流輸出為2A。系統操作於ACOT模式下可在廣負載變動範圍內提供良好的暫態回應,並於輸出電容的選擇上可選用具較小ESR的陶瓷電容,並確保整體系統表現的穩定性。此外,RT7274/79/80/81 在輸入與負載變動情形下仍能提供良好的固定操作頻率表現,內建的整流開關可允許在輸出在全負載變動範圍內提供良好的轉換效率。藉由偵測同步整流開關的端電壓可達到逐週期形式的限流機制,並可藉由外部的電容設計達到緩啟動效果,消除啟動時產生過大的輸入電湧。在保護機制方面,RT7274/79/80/81 均有過溫保護功能,而RT7279/80 則另含有輸出過電壓保護功能。

應用

  • 工業和商用低功率系統
  • 電腦週邊
  • 液晶顯示器和電視
  • 節能電器設備
  • 高性能 DSP、FPGA、ASIC 使用的負載點調節器
主要規格
RT7274 RT7279 RT7280 RT7281
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) 2 2 2 2
Current Limit (typ) (A) 3.5 3.5 3.5 3.5
Freq (typ) (kHz) 700 700 700 700
Ext Sync No No No No
Ron_HS (typ) (mOhm) 150 150 150 150
Ron_LS (typ) (mOhm) 105 105 105 105
Iq (typ) (mA) 0.7 0.7 0.7 0.7
Features ACOT Control;Adjustable Soft-Start;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;OCP;OTP;PSM;Power Good;Stable with Ceramic Capacitor;UVP ACOT Control;Adjustable Soft-Start;Cycle-by-Cycle Current Limit;Enable Input;Fast Transient Response;Force PWM;OCP;OTP;Power Good;Stable with Ceramic Capacitor;UVP ACOT Control;Adjustable Soft-Start;Enable Input;Fast Transient Response;OCP;OTP;PSM;Power Good;Stable with Ceramic Capacitor;UVP ACOT Control;Adjustable Soft-Start;Enable Input;Fast Transient Response;Force PWM;OCP;OTP;Power Good;Stable with Ceramic Capacitor;UVP
Package Type PSOP-8 TSSOP-14(PP);WDFN3x3-10 TSSOP-14(PP);WDFN3x3-10 PSOP-8
關鍵特性
  • 具ACOT™ 操作模式提供快速的暫態回應
  • 4.5V 至 18V 輸入電壓範圍
  • 最大2A 輸出電流
  • 具有針對低責任週期的應用的高效率內置N-MOSFET
  • 105mΩ的內部低端N-MOSFET
  • 進階的固定導通時間控制
  • 允許陶瓷電容作為輸出電容
  • 700kHz切換頻率
  • 可調輸出電壓範圍0.765V 至 8V
  • 可調整設計的緩啟動機制
  • 逐週期電流限制
  • 輸入欠壓閉鎖
  • 過溫保護
  • 符合RoHS規範與無鹵特性
Evaluation Boards
TitleLast UpdateDownload
RT7279GQW Evaluation Board2015/05/15
RT7280GQW Evaluation Board2015/05/15
Reference Design
TitleLast UpdateDownload
立錡負載暫態量測工具2018/11/01
Part NumberPackage TypePackage Qty.Free SampleDistributorStockBuy From Authorized Distributor
RT7274GSPPSOP-82,500 Request Digikey 458 Buy
Mouser 2,500 Buy
RT7279GCPTSSOP-14(PP)2,500 Request Digikey 351 Buy
Mouser 0 Lead-Time: 14 weeks
RT7279GQWWDFN3x3-101,500 Request Digikey 25,413 Buy
Mouser 7,244 Buy
RT7280GQWWDFN3x3-101,500 Request Digikey 957 Buy
Mouser 0 Lead-Time: 14 weeks
RT7281GSPPSOP-82,500 Request Digikey 2,397 Buy
Mouser 2,495 Buy
Evaluation Board
Part NumberDistributorStockBuy From Authorized Distributor
EVB_RT7279GQW Digikey 2 Buy
Mouser 5 Buy
EVB_RT7280GQW Digikey 5 Buy
Mouser 0 Lead-Time: 14 weeks
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