TPS56425xx 600KHz Synchronous Step-Down Converters

Introduction

Texas Instruments’ TPS56425xx series is a family of synchronous buck converter ICs designed to step down 3 V to 17 V input rails to regulated outputs between 0.6 V and 10 V. The devices combine integrated MOSFETs, support for up to 4 A continuous output current, and D-CAP3 control mode in a compact SOT-563 package.

The family is technically notable for its high-duty-cycle capability, low-ESR output-capacitor support, and compensation-free control architecture. Depending on the variant, switching frequency is either 600 kHz or 1.2 MHz, while light-load operation is available in Eco-mode, FCCM mode, or Out-of-Audio mode.

What it does

TPS56425xx devices convert a higher DC input voltage into a lower regulated supply rail using synchronous rectification. Integrated 55.0 mΩ and 24.3 mΩ MOSFETs reduce the need for external power switches, helping simplify the power-stage implementation.

D-CAP3 control mode eliminates the need for external compensation components and supports low-ESR output capacitors. The adjustable output range extends from the 0.6 V reference voltage up to 10 V, with reference accuracy specified as ±1% at 25°C and ±1.5% across a –40°C to 125°C junction-temperature range.

The 600 kHz TPS564252B, TPS564255B, and TPS564257B variants support up to 97% duty cycle. TPS564252C and TPS564257C versions operate at 1.2 MHz and support up to 95% duty cycle. A typical 1.6 ms soft-start time is specified.

Integrated protection functions include overvoltage protection (OVP), overcurrent protection (OCP), undervoltage lockout (UVLO), overtemperature protection (OTP), and undervoltage protection (UVP) with hiccup behavior.

Applications

• Point-of-load rails derived from 3 V to 17 V intermediate supply buses
• Digital supply rails requiring adjustable outputs from 0.6 V to 10 V
• Compact DC-DC power stages requiring up to 4 A continuous output current
• Systems that benefit from low-ESR output capacitors and no external compensation network
• Designs where selectable light-load behavior, including Eco-mode, FCCM, or Out-of-Audio mode, is relevant

Design considerations

The TPS56425xx family is supplied in a SOT-563 package, which supports compact board-level power conversion but requires appropriate PCB layout and thermal consideration for the intended load current and operating temperature.

Designers should select the variant according to switching-frequency and duty-cycle requirements: the B devices operate at 600 kHz with up to 97% duty cycle, while the C devices operate at 1.2 MHz with up to 95% duty cycle. The input supply must remain within the specified 3 V to 17 V range, and the required output must fall between 0.6 V and 10 V.

The D-CAP3 architecture is intended for use with low-ESR output capacitors and does not require external compensation. Light-load mode differs by variant, so Eco-mode, forced continuous-conduction mode, or Out-of-Audio operation should be matched to the system’s requirements.

Availability and further information

Further technical information is available through the Mouser Electronics source link and the Texas Instruments datasheet link provided on this page.