Diodes Incorporated

AP3445
Demoboard AP3445/L EVB User Guide

1MHZ, 2A STEP-DOWN DC-DC BUCK CONVERTER

Topology: Buck
Input Voltage (min.): 2.70 V
Input Voltage (max.): 5.50 V
Output 1: 3.30 V / 2.000 A

Original publication on 2017-11-24, revision 1.0 on

Description

The AP3445/L 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 AP3445/L 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 AP3445/L 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 AP3445/L 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 AP3445/L an ideal choice for high output voltage, high current applications which require a low dropout threshold. Pulse skip mode allows to maintain high efficiency at light-load conditions.

Characteristics

  • Output Current: Up to 2A
  • Output Voltage: 0.6V to VIN
  • Input Voltage: 2.7V to 5.5V
  • 55μA (Typ) No Load Quiescent Current
  • Shutdown Current: <1μA
  • 100% Duty Cycle Operation
  • 1MHz Switching Frequency
  • Internal Soft Start
  • No External Compensation Required
  • Current Limit Protection
  • 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

Products

  Order Code SPEC Product series L
(µH)
IR
(A)
ISAT
(A)
RDC typ.
(mΩ)
RDC max.
(mΩ)
fres
(MHz)
Montageart Samples
74438357022 PDF WE-MAPI SMT Power Inductor 2.2 5.2 7 22 26 35 SMT
74438357015 PDF WE-MAPI SMT Power Inductor 1.5 6.2 8.5 17.1 20 48 SMT
74438357010 PDF WE-MAPI SMT Power Inductor 1 7.4 9.6 11.6 13.5 59 SMT