onsemi 1N6377

Overview

1N6377 from ON Semiconductor is a unidirectional transient voltage suppressor (TVS) diode designed for parallel clamping protection of sensitive electronics against high-energy transients. It features a 15 V working peak reverse voltage (VRWM), 25 A peak pulse current (IPP), 20.1 V clamping voltage (VC) at IPP, 1500 W peak power rating at 1 ms, and sub-1 ns response time. It is used in industrial power supplies and communication interfaces to safeguard CMOS/MOS circuits.

For engineers reviewing the 1N6377 datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage margin relative to system operating voltage, surge current capability under IEC 61000-4-5 waveforms, thermal derating above 75°C lead temperature, and axial-leaded Surmetic package compatibility with through-hole PCB layouts.

Technical Context

The 1N6377 operates as a Zener-based avalanche clamp, triggered when reverse voltage exceeds its 17.6 V minimum breakdown voltage (VBR @ IT = 1 A). Its low dynamic impedance ensures stable clamping during fast transients, while its 20 °C/W junction-to-lead thermal resistance supports dissipation of 1500 W pulses with proper lead heatsinking.

Designed for non-repetitive surge suppression, it complies with Class 3 ESD (>16 kV HBM) and withstands forward surge currents up to 200 A (8.3 ms half-sine). Its unidirectional polarity-cathode marked by band-requires correct orientation in DC-biased protection paths, and it exhibits <2 µA leakage at 12 V.

Key Specifications

Pinout & Package

Package: Axial-leaded Surmetic plastic case (ON Semiconductor Case 41A), void-free thermosetting material, Pb-free compliant, cathode indicated by colored band.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ15A and 1N6376, G, the 1N6377 offers superior energy handling (1500 W vs. 600 W or same-family 1200 W) and optimized clamping (20.1 V) for 15 V systems-making it preferred for high-reliability industrial and telecom front-end protection where axial-leaded robustness is valued.

Availability

1N6377 is available at Aetrix Electronics and suitable for industrial power supplies, telecom interface protection, medical equipment input stages, and automotive body control modules requiring stable component supply and long-term obsolescence management.

Supply support for 1N6377 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

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

The 1N6377 belongs to the Mosorb 1N6373–1N6381 series-a family of high-power unidirectional TVS diodes engineered for rugged, cost-effective transient suppression in harsh electrical environments using axial-leaded Surmetic packaging.

FAQ

What is the maximum clamping voltage of the 1N6377 under rated surge conditions?

The 1N6377 has a maximum clamping voltage (VC) of 20.1 V when subjected to its rated peak pulse current of 25 A, measured per the 1 ms exponential waveform defined in Figure 5 of the datasheet. This value is guaranteed across manufacturing lots and forms the basis for safe margining against protected IC absolute maximum ratings. The 1N6377 maintains this clamping performance with minimal variation even at elevated ambient temperatures due to its low dynamic impedance.

Can the 1N6377 be used in bidirectional protection circuits?

No, the 1N6377 is strictly unidirectional and must be oriented with its cathode toward the protected line. It does not conduct in forward bias beyond typical diode drop (~3.5 V), nor does it suppress positive transients on grounded lines. For bidirectional protection, two 1N6377 devices may be connected in series opposing configuration-but this increases capacitance and requires careful layout. Dedicated bidirectional TVS like SMAJ15CA are recommended instead.

What is the thermal derating behavior of the 1N6377 above 75°C lead temperature?

The 1N6377's steady-state power dissipation (PD) is rated at 5.0 W up to 75°C lead temperature, then derated linearly at 20 mW/°C beyond that point. Its junction-to-lead thermal resistance is 20 °C/W, meaning a 5 W dissipation yields a 100°C temperature rise above lead temperature. For pulsed operation, Figure 1 shows peak power derating to ~70% at 100°C ambient-critical for enclosed industrial enclosures where airflow is limited.

How does the 1N6377 compare to the 1N6376, G in terms of breakdown voltage and application suitability?

The 1N6377 has a minimum breakdown voltage (VBR) of 17.6 V versus 14.1 V for the 1N6376, G-reflecting their respective 15 V and 12 V working peak reverse voltages (VRWM). This makes the 1N6377 appropriate for 15 V systems where tighter clamping margin is needed, while the 1N6376 suits 12 V rails. Both share identical package, surge rating, and construction; substitution requires verifying that the higher VBR of the 1N6377 does not delay clamping onset in low-voltage designs.

Is the 1N6377 RoHS-compliant and compatible with lead-free soldering processes?

Yes, the "G" suffix in 1N6377, G explicitly denotes a Pb-free package compliant with RoHS Directive 2011/65/EU. Its leads are rated for soldering at 260°C for 10 seconds at 1/16″ from the case, matching standard lead-free reflow profiles. The Surmetic plastic body is void-free and thermosetting, ensuring mechanical stability during multiple thermal cycles without delamination or cracking.