Taiwan Semiconductor Corporation MUR305SB

Overview

MUR305SB from Taiwan Semiconductor is an ultra-fast recovery surface-mount power rectifier with 50 V repetitive peak reverse voltage (V_RRM), 3 A average forward current (I_F), and 25 ns reverse recovery time (t_rr), designed for high-efficiency switching mode power supplies in compact consumer electronics.

For engineers reviewing the MUR305SB datasheet, MUR305SB pinout, MUR305SB application, or MUR305SB equivalent, key selection considerations include its DO-214AA (SMB) package, 0.85 V max forward voltage at 3 A/25°C, 75 A surge rating, 175°C maximum junction temperature, and RoHS/halogen-free compliance for industrial and consumer-grade SMPS designs.

Technical Context

The MUR305SB is a single-die, silicon planar ultra-fast rectifier optimized for high-frequency switching applications where low conduction loss and minimal reverse recovery charge are critical. Its glass-passivated junction ensures stable performance under thermal cycling and humidity stress.

With a typical junction-to-lead thermal resistance of 42°C/W and rated for operation from –55°C to +175°C, the MUR305SB supports reliable power conversion in space-constrained PCB layouts using standard SMB footprint and matte tin-plated leads compliant with J-STD-002 solderability.

Key Specifications

Pinout & Package

Package: DO-214AA (SMB), surface-mount, single-anode/single-cathode configuration. Cathode indicated by band on body. Matte tin-plated leads, J-STD-002 solderable, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-fast power rectifier applications.

Compared with STTH3L06S and MUR305S, the MUR305SB offers optimal balance of 50 V blocking, 25 ns speed, and cost-effective SMB packaging for fixed-input 50 V SMPS-making it preferred for consumer-grade adapter and monitor power where voltage margin and thermal headroom are tightly managed.

Availability

MUR305SB is available at Aetrix Electronics and suitable for switching mode power supplies, AC-DC adapters, and flat-panel monitor power systems requiring stable component supply, consistent parametric performance, and full RoHS/halogen-free compliance.

Supply support for MUR305SB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in power rectifiers, TVS diodes, MOSFETs, and LED drivers since 1979.

The MUR305SB belongs to TSC's MUR3xSB ultra-fast rectifier family, engineered specifically for high-frequency, high-efficiency AC-DC and DC-DC conversion in space-constrained consumer and industrial power supplies.

FAQ

What is the maximum junction temperature rating for the MUR305SB?

The MUR305SB has a maximum junction temperature (T_J) rating of +175°C, verified per absolute maximum ratings table in the official Taiwan Semiconductor datasheet revision C2102. This allows continuous operation in thermally demanding environments such as enclosed power adapters or industrial control units without forced cooling. The MUR305SB maintains stable electrical parameters up to this limit when mounted on a 10 mm × 10 mm copper pad per JEDEC test conditions.

Is the MUR305SB compatible with lead-free reflow soldering processes?

Yes, the MUR305SB is fully compatible with lead-free reflow soldering. Its matte tin-plated leads meet J-STD-002 solderability requirements, and its moisture sensitivity level is rated at Level 1 per J-STD-020-meaning it can be stored indefinitely at ≤30°C/60% RH without baking prior to assembly. The MUR305SB withstands peak reflow temperatures up to 260°C for 10 seconds, supporting standard Pb-free SAC305 profiles.

What does the "SB" suffix indicate in MUR305SB?

The "SB" suffix in MUR305SB denotes the DO-214AA (SMB) package variant per Taiwan Semiconductor's ordering nomenclature. It distinguishes this surface-mount version from through-hole alternatives (e.g., MUR305G in DO-201AD). The "SB" code confirms the device uses the SMB outline with cathode band marking, matte tin leads, and UL 94V-0 molding compound-key identifiers used in the MUR305SB datasheet Version C2102.

How does the reverse recovery time of the MUR305SB compare to standard fast recovery diodes?

The MUR305SB specifies a maximum reverse recovery time (t_rr) of 25 ns under standardized test conditions (I_F = 0.5 A, I_R = 1.0 A, I_rr = 0.25 A), which is approximately 40–60% faster than conventional fast recovery diodes (typically 50–100 ns). This enables higher switching frequencies and reduced EMI in SMPS designs. The MUR305SB achieves this via optimized lifetime control and ultra-fast carrier recombination in its silicon die.

Can the MUR305SB replace a 1N5822 in an existing design?

No, the MUR305SB is not a direct replacement for the 1N5822. While both are 3 A Schottky-like rectifiers, the 1N5822 is a Schottky diode (V_F ≈ 0.5 V, no reverse recovery), whereas the MUR305SB is a silicon ultra-fast PN rectifier (V_F ≈ 0.85 V, t_rr = 25 ns). Substituting MUR305SB for 1N5822 introduces higher conduction loss and potential ringing due to minority-carrier recovery. Use MUR305SB only where its 50 V rating and fast recovery are explicitly required-not as a generic 3 A diode swap.