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Announcement

New Product

diodes.com

The AP61406Q is a new 5.5V, 4A,

automotive-compliant* synchronous buck

converter. Its I2C interface allows for low

quiescent current (IQ) and the programming of

various parameters, enabling the device to

meet the growing demands for compact

designs and high efficiency in automotive

point-of-load (POL) applications.

The device features an I2C-compatible, two-

wire serial interface consisting of a

bidirectional serial-data line (SDA), and a

serial-clock line (SCL) with supported rates up

to 3.4MHz.

The AP61406Q operates with an input voltage

range of 2.3V to 5.5V. It integrates a 75mΩ

high-side and a 33mΩ low-side power

MOSFET to provide high-efficiency step-down

DC-DC conversion. Its adoption of constant

on-time (COT) control minimizes external

component count, facilitates loop stabilization,

and results in a low output voltage ripple.

For high power density, the AP61406Q is

available in the tiny W-QFN1520-8/SWP

(Type UX) package.

A standard-compliance version, AP61406, is

available and suitable for industrial and

commercial applications.

*Automotive-compliant - AEC qualified, manufactured in

facilities certified to IATF 16949, supporting PPAP

documents.

The Diodes logo is a registered trademark of Diodes

Incorporated in the United States and other countries.

All other trademarks are the property of their respective

owners.

© 2025 Copyright Diodes Incorporated. All Rights

Reserved.

I2C 5.5V, 4A, Synchronous Buck Converter Provides a

Versatile High Power Density Automotive POL Solution

Applications

Automotive 5V and 3.3V POL in:

▪ Infotainment

▪ Instrument clusters

▪ Telematics

▪ Advanced Driver Assistance

Systems (ADAS)

The DIODES Advantage

The AP61406Q's I2C interface, low IQ, inclusion of constant

on-time control allows for programmable parameters in a

highly efficient, small form factor design.

▪ I2C Interface with up to 3.4MHz SCL Clock Rates to

Program PFM/PWM, fSW (1MHz, 1.5MHz, 2MHz, 2.5MHz),

IOUT (1A/2A/3A/4A), VOUT (20mV steps), and Fault Status

Reporting

Provides increased versatility and ease of design

▪ Operates at 4A Maximum Output Current in the Tiny

W-QFN1520-8/SWP (Type UX)

Provides high power density for high ambient temperature

operation in automotive POL applications

▪ Accurate PG with ±5% window comparator and Internal

5MΩ Pull-up

Accurate fault detection while reducing BOM costs

▪ Multi-Function EN Controls PFM/PWM Modes of Operation

Provides flexibility for low IQ high-light-load efficiency or equal

ripple across load conditions in fixed PWM

▪ High-Side and Low-Side Current Sense Protection During

Output Short

Increases robustness in automotive POL applications

AP61406Q

December 2025