Is there a pin-compatible replacement for 1SMA4747A?

Yes, parts like 1SMA4746 and 1SMA5931H are pin-compatible in the same SMA package. However, their electrical parameters, specifically the Zener voltage, differ from the target.

What risks should I check before replacing 1SMA4747A?

The most critical risk is the Zener voltage (Vz). Ensure the substitute's Vz meets your circuit's regulation needs. Also verify power dissipation, tolerance, and dynamic impedance (Zzt).

1SMA4747A Alternatives, Datasheet & Cross Reference | Good-Ark Semiconductor

Finding a substitute for the 1SMA4747A Zener diode requires matching its 20V Zener voltage, 1W power rating, and SMA package. While several alternatives exist in the same package, careful attention to Zener voltage is critical.

AI replacement insight

Electrical riskhigh

Zener voltage is a critical parameter for regulation; deviation requires circuit analysis.

Package risklow

Candidates share the same DO-214AC (SMA) package, ensuring form-fit compatibility.

Can it be replaced directly?

No direct, drop-in replacement was found among the candidates. All form-fit options have a different Zener voltage, which is a critical parameter.

Best replacement path

Search for a Zener diode with Vz=20V, Pmax>=1W, and a DO-214AC (SMA) package. Candidates like 1SMA5931H offer higher power but at 18V, requiring analysis.

Main risk

The primary risk is Zener voltage mismatch, which can lead to improper voltage regulation or circuit failure.

Recommended alternatives

Form-fit compatible with higher power (1.5W) and better impedance, but Zener voltage is 18V instead of 20V.

View details

Alternative comparison matrix

Feature / factor	1SMA4747A	1SMA5931H	1SMA4746	Compatibility / risk
Package	DO-214AC, SMA	DO-214AC (SMA)	DO-214AC (SMA)	DO-214AC (SMA) — Form-fit compatible.; 1SMA4746: Form-fit compatible.
Voltage	20 V	18 V	18 V	18 V — Zener voltage is lower.; 1SMA4746: Zener voltage is 10% lower.
Power	1 W	1.5 W	1 W	1.5 W / 1 W — Higher power rating provides more margin.; 1SMA4746: Power rating is identical.
Impedance	22 Ohms	10-12 Ω	-	10-12 Ω — Lower impedance offers better regulation.
Tolerance	±5%	-	±5% or ±10%	±5% or ±10% — Tolerance may be wider.

Application & sourcing insights

Questions & answers

No perfect drop-in alternative was found. 1SMA5931H is a potential functional alternate with higher power (1.5W) but a lower Zener voltage (18V), requiring engineering review.