onsemi NP3100SBT3G

Overview

NP3100SBT3G from onsemi is a bidirectional thyristor surge protector (TSPD) designed for overvoltage clamping in telecom line interfaces. It features 275 V peak off-state voltage (V_DRM), 350 V breakover voltage (V_BO), 4.0 V on-state voltage (V_T), 150 mA holding current (I_H), and supports 500 A_(pk) 10×1000 µs surge current per GR-1089-CORE. It protects central office, access, and customer premises equipment.

For engineers reviewing the NP3100SBT3G datasheet, pinout, applications, or equivalent options, key selection criteria include bidirectional crowbar action, SMB package compatibility, compliance with ITU-T K.20/K.21/GR-1089-CORE, thermal resistance of 90 °C/W, and 150 mA holding current ensuring reliable latch-off after surge clearance.

Technical Context

The NP3100SBT3G operates as a voltage-triggered bidirectional crowbar device: it remains high-impedance below 275 V (V_DRM) and switches to low-impedance conduction above 350 V (V_BO) in either polarity. Its 4.0 V on-state voltage limits power dissipation during clamping, while 150 mA holding current ensures stable latching until fault current drops below threshold.

It delivers 500 A_(pk) surge capability under 10×1000 µs waveform per GR-1089-CORE, with critical dv/dt rating of 5.0 kV/s preventing false triggering. Thermal resistance of 90 °C/W (Junction-to-Ambient, FR4 PCB) enables operation from −40 °C to +150 °C without derating in typical telecom board layouts.

Key Specifications

Pinout & Package

NP3100SBT3G uses the SMB (DO-214AA, Case 403C) surface-mount package: 4.06–4.57 mm length, 3.30–3.81 mm width, 1.90–2.41 mm height, with gull-wing leads optimized for automated assembly and thermal relief on FR4 PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar thyristor surge protector applications.

Compared with NP3100SAT3G and NP3100SCT3G, the NP3100SBT3G offers balanced performance for medium-duration surges (10×1000 µs), making it optimal for GR-1089-CORE Class B compliance in access network equipment where sustained energy handling matters more than peak amplitude.

Availability

NP3100SBT3G is available at Aetrix Electronics and suitable for digital subscriber line (xDSL) modems, central office line cards, and customer premises equipment requiring stable component supply, RoHS-compliant packaging, and GR-1089-CORE certification.

Supply support for NP3100SBT3G 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and communications markets.

The NP Series TSPDs were developed specifically for telecom infrastructure protection, delivering bidirectional crowbar action in compact SMB packages to replace dual-SCR designs while meeting stringent ITU-T and GR-1089 regulatory requirements.

FAQ

What is the maximum continuous operating voltage for NP3100SBT3G?

The NP3100SBT3G has a peak off-state voltage (V_DRM) of 275 V, meaning it can continuously block up to 275 V in either polarity without conduction. This rating applies at T_J = 25°C and derates slightly at elevated junction temperatures; full derating curves are provided in Figure 4 of the NP0640S/D datasheet. The NP3100SBT3G must not be subjected to sustained voltages exceeding this value in normal operation.

How does NP3100SBT3G differ from NP3100SAT3G and NP3100SCT3G?

The NP3100SBT3G, NP3100SAT3G, and NP3100SCT3G share identical electrical parameters (V_DRM, V_BO, V_T, I_H) and SMB packaging, differing only in surge classification marking and tested waveform compliance. NP3100SBT3G is marked "310B" and validated for 50 A_(pk) 10×1000 µs (GR-1089-CORE Class B), whereas NP3100SAT3G ("310A") covers Class A and NP3100SCT3G ("310C") covers Class C. The NP3100SBT3G is thus optimized for medium-duration surge events common in access networks.

Can NP3100SBT3G be used in DC circuits?

Yes, the NP3100SBT3G functions in DC applications as a bidirectional crowbar: it remains non-conductive below 275 V and triggers at 350 V in either polarity. However, its 150 mA holding current requires the protected circuit to drop below that threshold to reset - so DC systems must ensure fault current interruption (e.g., via fuse or current-limiting resistor) after triggering. The NP3100SBT3G is commonly deployed in DC-powered telecom line interfaces where this behavior is well-characterized and managed.

What is the thermal resistance of NP3100SBT3G and how does it affect layout?

The NP3100SBT3G has a Junction-to-Ambient thermal resistance (R_θJA) of 90 °C/W when mounted on a 3″×4.5″ FR4 PCB with 2 oz copper and 3×3 inch fan-out pattern. This means each watt of clamping power raises junction temperature by 90°C above ambient. To avoid exceeding the +150°C max operating temperature, designers must limit average surge duty cycle and ensure adequate copper area around the SMB pads - the NP3100SBT3G's thermal performance directly impacts reliability in repeated surge events.

Does NP3100SBT3G require a gate trigger or external control circuit?

No, the NP3100SBT3G is a passive, voltage-triggered device with no gate terminal or control input. It relies solely on intrinsic thyristor physics: when voltage across MT1–MT2 exceeds 350 V (V_BO) in either direction, it switches to low-impedance conduction without external signals. This self-triggering behavior makes the NP3100SBT3G simple to integrate - no driver ICs, timing circuits, or bias networks are needed, reducing BOM count and layout complexity.