onsemi NP2100SAT3G

Overview

NP2100SAT3G from onsemi is a bidirectional thyristor surge protector (TSPD) designed for overvoltage clamping in telecom line interfaces. It features 180 V peak off-state voltage (V_DRM), 240 V breakover voltage (V_BO), 4.0 V on-state voltage (V_T), 150 mA holding current (I_H), and supports 500 A(pk) 2×10 µs surge current - deployed in central office and customer premises equipment to meet GR-1089-CORE and ITU-T K.20/21.

For engineers reviewing the NP2100SAT3G datasheet, pinout, applications, or equivalent options, key selection criteria include bidirectional crowbar action, SMB package compatibility, 150°C operating junction temperature, low capacitance (37 pF at 1 MHz), and compliance with IEC 61000-4-5 and TIA-968-A surge standards.

Technical Context

The NP2100SAT3G operates as a voltage-triggered silicon-controlled rectifier (SCR) with symmetrical forward/reverse characteristics. Its breakover threshold of 240 V ensures precise clamping before downstream IC damage, while the 4.0 V on-state voltage sustains low power dissipation during crowbar conduction.

It exhibits 5.0 kV/µs critical dv/dt rating and 500 A/µs di/dt capability, enabling robust response to fast-rising transients without false triggering. Thermal resistance of 90°C/W (Junction-to-Ambient, FR4 PCB) supports reliable operation under repeated surge events in unheatsinked layouts.

Key Specifications

Pinout & Package

SMB package (JEDEC DO-214AA, Case 403C), surface-mount, bidirectional two-terminal device. No internal control pin - MT1 and MT2 are symmetrical main terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NP2100SBT3G and NP2100SCT3G, the NP2100SAT3G offers identical protection performance and SMB mounting but is distinguished by its "210A" top-side marking and standard 2500-unit tape-and-reel shipping configuration - making it the default reference variant for schematic symbol and BOM designation.

Availability

NP2100SAT3G is available at Aetrix Electronics and suitable for DSL line interface protection, ISDN BRI circuits, and central office line card designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant surge suppression.

Supply support for NP2100SAT3G 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, sensor, and logic solutions for automotive, industrial, cloud, and communications markets.

The NP Series TSPDs were engineered specifically for telecom infrastructure protection - delivering bidirectional, low-capacitance, high-surge-current clamping in standardized surface-mount packages for central office, access network, and CPE applications.

FAQ

What is the primary function of the NP2100SAT3G in a telecom circuit?

The NP2100SAT3G functions as a bidirectional thyristor surge protector (TSPD) that acts as a crowbar device - remaining high-impedance under normal operating voltage (up to 180 V V_DRM) and rapidly switching to low-impedance conduction when voltage exceeds 240 V (V_BO). This diverts surge current away from sensitive downstream components such as line drivers or codecs. The NP2100SAT3G is rated for 500 A(pk) 2×10 µs surges and maintains this behavior symmetrically across both polarities.

Does the NP2100SAT3G require a gate drive or external trigger circuit?

No, the NP2100SAT3G is a gateless, voltage-triggered device - it requires no external bias, control signal, or gate drive. Conduction initiates solely when the voltage across MT1–MT2 exceeds the breakover threshold (240 V) in either polarity. Once triggered, it latches "on" until current falls below the 150 mA holding current (I_H). This self-triggering behavior makes the NP2100SAT3G ideal for passive, fail-safe surge protection without supporting active circuitry.

Can the NP2100SAT3G be used in DC applications?

The NP2100SAT3G is optimized for AC-coupled telecom line protection and is not recommended for pure DC bus protection. Its bidirectional symmetry and specified surge waveforms (e.g., 10×160 µs, 2×10 µs) assume alternating polarity transients. In DC systems, sustained overvoltage could cause uncontrolled latch-up if load current remains above 150 mA, preventing natural commutation. For DC applications, discrete TVS diodes or dedicated DC-rated TSPDs with asymmetric or unidirectional characteristics are preferred over the NP2100SAT3G.

What is the thermal derating behavior of the NP2100SAT3G at elevated ambient temperatures?

The NP2100SAT3G has a maximum junction temperature of +150°C and a thermal resistance of 90°C/W (Junction-to-Ambient, FR4 PCB). At ambient temperatures above 75°C, the allowable surge duty cycle must be reduced to prevent cumulative heating - for example, repeated 500 A surges at 1 Hz require heatsinking or airflow beyond the standard JEDEC test board. Derating curves are provided in the official NP0640S/D datasheet; the NP2100SAT3G shares identical thermal specifications with other NP Series devices.

How does the 37 pF capacitance of the NP2100SAT3G affect high-speed data lines?

The 37 pF capacitance of the NP2100SAT3G (measured at 1 MHz, 2 Vdc bias) introduces negligible insertion loss on xDSL, ISDN, and T1/E1 lines - for example, at 2 MHz, capacitive reactance is ~2.1 kΩ, which is >100× higher than typical line impedances (100–120 Ω). This ensures minimal signal attenuation or phase shift. However, in >10 MHz applications (e.g., VDSL2 vectoring), additional filtering or layout optimization may be needed, as the NP2100SAT3G's capacitance is fixed and not tunable.