Is there a pin-compatible replacement for LMR51420XDDCR?

Yes, the LMR51430XFDDCR is a pin-compatible replacement. It shares the same SOT-23-6 package and pin functions, allowing for a drop-in upgrade to 3A of current.

What risks should I check before replacing LMR51420XDDCR?

Before replacing, check three main risks: 1) Input Voltage Range: Ensure the replacement supports your system's maximum voltage. 2) Switching Frequency: A different frequency requires changing external components. 3) Pinout: Always verify the pinout is identical to avoid damaging your board.

LMR51420XDDCR Alternatives, Datasheet & Cross Reference | Texas Instruments

Find the best replacement for the LMR51420XDDCR, a 36V 2A synchronous buck converter. This guide reviews official upgrades, pin-compatible alternatives, and functional substitutes to meet your design needs.

AI replacement insight

Electrical riskhigh

Many alternatives have a lower max input voltage (e.g., 18V vs 36V) or different switching frequency.

Package risklow

SOT-23-6 is a common package, but pinout must be verified for non-TI parts.

Sourcing riskmedium

Official TI upgrades are reliable, but cross-vendor parts may have different supply chain stability.

Can it be replaced directly?

Yes, the LMR51430XFDDCR from Texas Instruments is a pin-compatible upgrade. It provides 3A of output current versus the original 2A.

Best replacement path

The LMR51430XFDDCR is the recommended upgrade, offering 3A current with the same package, voltage range, and switching frequency.

Main risk

The primary risk when considering cross-vendor alternatives is a lower maximum input voltage, which could damage the part in a 24V or 36V system.

Recommended alternatives

Official 3A upgrade from TI in the same family with matching voltage, frequency, and package.

View details

Alternative comparison matrix

Feature / factor	LMR51420XDDCR	LMR51430XFDDCR	LMR51430YFDDCR	SM8102ABC	Compatibility / risk
Voltage	4.5V to 36V	4.5V to 36V	4.5V to 36V	4.2V to 18V	4.5V to 36V / 4.2V to 18V — Input voltage range matches.; LMR51430YFDDCR: Input voltage range matches.; SM8102ABC: Max input voltage is much lower.
Current	2.0A	3.0A	3.0A	2.0A	3.0A / 2.0A — Higher output current capability.; LMR51430YFDDCR: Higher output current capability.; SM8102ABC: Output current matches.
Switching Frequency	500kHz	500kHz	1.1MHz	500kHz	500kHz / 1.1MHz — Switching frequency matches.; LMR51430YFDDCR: Higher frequency requires recalculating external components (inductor, capacitors).; SM8102ABC: Switching frequency matches.
Package	SOT-23-6	SOT-23-6	SOT-23-6	SOT23-6	SOT-23-6 / SOT23-6 — Package and pinout are compatible.; LMR51430YFDDCR: Package is compatible.; SM8102ABC: Package matches.
Application	PFM/PWM	FPWM	-	-	FPWM — Candidate uses Forced PWM, target has PFM mode for light loads. May affect light-load efficiency.

Application & sourcing insights

Questions & answers

The best alternative is the LMR51430XFDDCR. It is a pin-compatible upgrade from the same manufacturer (Texas Instruments) with a higher 3A output current and matching key parameters.