Diodes Incorporated

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The AP3445L is a 2A step-down DC-DC converter. At heavy load, the constant-frequency PWM control performs excellent stability and transient response. No external compensation components are required.

The AP3445L supports a range of input voltages from 2.7V to 5.5V allowing the use of a single Li+/Li-polymer cell, multiple Alkaline/NiMH cell, and other standard power sources. The output voltage is adjustable from 0.6V to the input voltage. The AP3445L employs internal power switch and synchronous rectifier to minimize external part count and realize high efficiency. During shutdown, the input is disconnected from the output and the shutdown current is less than 1μA. Other key features include over-temperature and short circuit protection, and under-voltage lockout to prevent deep battery discharge.

The AP3445L delivers 2A maximum output current while consuming only 55μA of no-load quiescent current. Ultra-low RDS(ON) integrated MOSFETs and 100% duty cycle operation make the AP3445L an ideal choice for high output voltage, high current applications which require a low dropout threshold. Pulse skip mode to maintain high efficiency at light-load conditions.

The AP3445L is available in SOT26 (SC74R) package.


  • Input Voltage: 2.7V to 5.5V
  • Output Voltage: 0.6V to VIN
  • 0.6V Reference Voltage with ±1.5% Precision
  • 55µA (Typ) No Load Quiescent Current
  • Shutdown Current: <1µA
  • 100% Duty Cycle Operation
  • 1MHz Switching Frequency
  • No External Compensation Required
  • Short Circuit Protection

AP3445L: Latch Off Protection

AP3445: Hiccup Mode Protection

  • Over Voltage Protection

AP3445L: Latch Off Protection

AP3445: Non Latch Off Protection

  • Thermal Shutdown


  • Post DC-DC Voltage Regulation
  • Set Top Boxes
  • Notebook Computer
  • PAD

Product Specifications

Product Parameters

Compliance(Only Automotive supports PPAP) Standard
Type Buck
Minimum Input Voltage (V) 2.5
Maximum Input Voltage (V) 5.5
Output Current (A) 2
Minimum Output Voltage (V) 0.6
Maximum Output Voltage (V) VIN
Quiescent Current Typ (µA) 55
Shutdown Current Typ (µA) N/A
Frequency Typ (kHz) 1000

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Technical Documents

Evaluation Boards and User Guides

Recommended Soldering Techniques


Product Change Notices (PCNs)

A PCN may only apply to specific orderable part numbers in this datasheet. Please refer to the corresponding PCN to see the exact orderable part number(s) affected.

PCN # Issue Date Implementation Date Subject
PCN-2531 2021-07-30 2022-01-29 Additional Die Revision, Redistribution Layer (RDL), BUMP Sites (SJSEMI and LBS), as well as Assembly/Test (A/T) Site (CAT)
PCN-2512 2021-04-16 2021-07-16 Qualified Additional Assembly & Test (A/T) Site