Is there a pin-compatible replacement for LMR51420YFDDCR?

No candidate has been confirmed to be 100% pin-compatible. LMR51430XDDCR, being from the same family, has the highest probability but must be verified by comparing datasheet pinout diagrams. A board layout change may be necessary.

What risks should I check before replacing LMR51420YFDDCR?

Before replacing, you must check three main risks: 1) Input Voltage Range: Many alternatives have a lower max input voltage. 2) Switching Frequency: A mismatch requires changing the inductor and capacitors. 3) Pinout: Verify the pin configuration to ensure it matches your PCB layout.

LMR51420YFDDCR Alternatives, Datasheet & Cross Reference | Texas Instruments

Explore replacements for the Texas Instruments LMR51420YFDDCR 36V, 2A buck converter. Find upgrade paths like the LMR51430XDDCR and other functional alternatives, but be prepared for circuit redesign due to parametric differences.

AI replacement insight

Electrical riskhigh

Different switching frequencies and control modes (COT vs. PWM) require redesign and validation.

Package riskmedium

While packages match (SOT-23-6), pinouts are not verified and may differ, preventing a drop-in fit.

Sourcing risklow

Multiple functional alternatives exist from various vendors, though with significant parametric differences.

Can it be replaced directly?

No direct drop-in replacement has been identified. The closest candidate, LMR51430XDDCR, requires circuit modifications due to a different switching frequency.

Best replacement path

Upgrade to LMR51430XDDCR for higher 3A current. This part is from the same manufacturer and family, but requires circuit redesign for its 500kHz switching frequency.

Main risk

The primary risk is electrical incompatibility. Most alternatives have different switching frequencies, requiring recalculation of external components like the inductor and capacitors to ensure stability and performance.

Recommended alternatives

Upgrade path from the same manufacturer with higher current, but requires redesign for different switching frequency.

View details

Alternative comparison matrix

Feature / factor	LMR51420YFDDCR	LMR51430XDDCR	TMI3244T	Compatibility / risk
Package	SOT-23-6	SOT-23-6	SOT23-6	SOT-23-6 / SOT23-6 — Package matches.; TMI3244T: Package matches.
Voltage	4.5V - 36V	4.5V - 36V	4.5V - 18V	4.5V - 36V / 4.5V - 18V — Input voltage range matches.; TMI3244T: Significantly lower max input voltage.
Current	2A	3A	4A	3A / 4A — Higher output current capability.; TMI3244T: Higher output current.
Switching Frequency	1.1 MHz	500 kHz	550 kHz	500 kHz / 550 kHz — Frequency differs, requires external component recalculation (inductor, capacitors).; TMI3244T: Frequency differs, requires redesign.
Temperature	-40°C to 150°C	-40°C to 150°C	-40°C to 125°C	-40°C to 150°C / -40°C to 125°C — Operating temperature range matches.; TMI3244T: Reduced max operating temperature.

Application & sourcing insights

Questions & answers

The best alternative is LMR51430XDDCR from Texas Instruments. It offers a higher 3A output current and matching input voltage range, but its different switching frequency (500kHz vs 1.1MHz) requires redesign of external components.