Semtech Corporation SRDA05-4.TBT

Overview

SRDA05-4.TBT from Semtech is a transient diverting suppressor (TDS) designed for high-energy EOS protection of 22V-rated power or I/O lines, featuring ±30kV IEC 61000-4-2 ESD immunity, 40A peak pulse current (8/20μs), 27.5–28V clamping voltage at 40A, and ultra-low 20mΩ dynamic resistance. It protects USB Type-C power delivery buses, load switch inputs, and industrial I/O interfaces where stable clamping under temperature and current stress is critical.

For engineers reviewing the SRDA05-4.TBT datasheet, pinout, applications, or equivalent options, this device offers constant-voltage clamping performance distinct from conventional TVS diodes - making it essential for designs requiring predictable surge protection across -40°C to +125°C and up to 40A transients without voltage drift.

Technical Context

The SRDA05-4.TBT uses a surge-rated FET as its primary protection element, activated by a precision trigger circuit that senses overvoltage events and rapidly turns on the shunt path. Unlike standard TVS diodes, its clamping voltage remains nearly constant (27.5–28V) across the full 1–40A peak pulse current range due to decreasing R_DS(on) under surge conditions.

It operates with a 22V reverse stand-off voltage (V_RWM), 25–27.9V breakdown (V_BR), and exhibits only 175pF junction capacitance at 22V - enabling use in high-speed bus protection without signal integrity degradation. Its DFN 1.6×1.6×0.55mm package integrates three parallel input terminals (Pins 4–6) and three ground terminals (Pins 1–3) to maximize surge current handling and minimize parasitic inductance.

Key Specifications

Pinout & Package

SRDA05-4.TBT is housed in a RoHS-compliant, halogen-free DFN package measuring 1.6mm × 1.6mm × 0.55mm with exposed thermal pad (no internal thermal pad required; energy dissipated in silicon). All six leads are soldered directly to PCB for mechanical stability and low-inductance grounding.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient suppression applications.

Compared with TDS2211P and SRDA05-4.TCT, the SRDA05-4.TBT delivers identical protection performance and package geometry but is optimized for standard 7″ reel logistics and common distributor inventory - making it the preferred choice for mid-volume production and engineering sampling where tape format alignment matters.

Availability

SRDA05-4.TBT is available at Aetrix Electronics and suitable for USB Type-C power delivery systems, industrial load switch interfaces, and IoT device power rail protection requiring stable component supply, consistent surge performance, and long-term lifecycle support.

Supply support for SRDA05-4.TBT 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

Semtech Corporation is a U.S.-based fabless semiconductor company specializing in high-performance analog and mixed-signal ICs for precision sensing, protection, and signal integrity.

The SRDA05-4.TBT belongs to Semtech's Transient Diverting Suppressor (TDS) product line, engineered to replace conventional TVS diodes in high-reliability power rail protection where constant clamping voltage and temperature stability are mandatory.

FAQ

What is the exact function of SRDA05-4.TBT in a circuit?

The SRDA05-4.TBT functions as a transient diverting suppressor that actively shunts high-energy EOS events - such as ESD, lightning-induced surges, and EFT bursts - away from downstream components. It does so by triggering a precision-controlled FET to conduct surge current to ground while maintaining a tightly regulated 27.5–28V clamping voltage. This behavior is fundamentally different from passive TVS diodes and makes SRDA05-4.TBT especially valuable in 22V power rail protection where voltage margin is constrained.

Is SRDA05-4.TBT pin-compatible with standard TVS diodes in DFN-6 packages?

No - SRDA05-4.TBT is not pin-compatible with generic DFN-6 TVS diodes. Its pinout requires all three input pins (4–6) and all three ground pins (1–3) to be connected simultaneously to achieve rated 40A surge capability. Standard unidirectional TVS diodes in DFN-6 typically use a single anode/cathode configuration. Using SRDA05-4.TBT as a drop-in replacement without verifying layout and routing will result in degraded surge performance.

Does SRDA05-4.TBT require a thermal pad on the PCB?

No, SRDA05-4.TBT does not require a thermal pad. The device dissipates surge energy within the silicon FET structure rather than relying on junction-to-case conduction. Semtech's datasheet explicitly states "no thermal pad is needed" and recommends connecting all GND pins (1–3) directly to a solid ground plane via multiple vias to minimize inductance - not to enhance thermal transfer.

Can SRDA05-4.TBT be used on data lines like USB SuperSpeed or PCIe?

No - SRDA05-4.TBT is not intended for high-speed data line protection. With 175pF junction capacitance, it would severely degrade signal integrity on differential pairs operating above ~100MHz. It is specifically designed for power rails and low-speed control lines (e.g., CC, SBU, enable signals). For USB SS or PCIe lanes, Semtech recommends dedicated low-capacitance protectors like RClamp3371ZC (<0.25pF).

What is the meaning of "TBT" in SRDA05-4.TBT?

The "TBT" suffix in SRDA05-4.TBT denotes Semtech's tape-and-reel packaging variant: "T" = Tape, "B" = 7-inch reel, "T" = standard carrier tape configuration. It is functionally and electrically identical to TDS2211P and SRDA05-4.TCT (which uses a 13-inch reel). The SRDA05-4.TBT designation appears in Semtech's official ordering information and distributor catalogs as a valid, fully qualified part number for the same silicon and package.