Diodes Incorporated – AP3401 and AP3428: 1A DC-DC Buck Converters Achieve High Light-Load Efficiency


The AP3401/AP3428 is a current mode, PWM synchronous buck DC-DC converter, capable of driving a 1A load with high efficiency and excellent line and load regulation. AP3401/AP3428 delivers 1A maximum output current while consuming only 40μA no-load quiescent current. Ultra-low RDS(ON) integrated MOSFETs and 100% duty cycle operation make it an ideal choice for high current applications which require a low dropout threshold. AP3401/AP3428 has built-in protection features and the AP3401 features a Power-Good output.

• Up to 1A output current
• 2.5V to 5.5V input voltage range
• 40μA no-load quiescent current
• 1.5MHz switching frequency
• No external compensation required
• 0.6V to VIN output voltage range
• 0.6V reference voltage with ±2% precision
• 100% duty cycle operation
• Internal soft start
• Current limit protection