Renesas NNCD27ST(0)-T1-AT

Overview

NNCD27ST(0)-T1-AT from Renesas Electronics is an ESD noise clipping diode designed for bidirectional transient voltage suppression on CAN bus lines. It features a breakdown voltage of 25–31 V, 11 pF typical capacitance at 1 MHz, 0.1 μA max reverse leakage at 21 V, 85 W surge reverse power (10 μs pulse), and is housed in a 3-pin SC-70 (Super Mini Mold) package. It is rated for automotive-grade CAN physical layer protection per IEC61000-4-2.

For engineers reviewing the NNCD27ST(0)-T1-AT datasheet, NNCD27ST(0)-T1-AT pinout, NNCD27ST(0)-T1-AT application, or NNCD27ST(0)-T1-AT equivalent, key selection criteria include bidirectional clamping voltage window, low junction capacitance for high-speed CAN signal integrity, Pb-free SC-70 footprint compatibility, and IEC61000-4-2 Level 4 ESD robustness in compact automotive network nodes.

Technical Context

This device operates as a bidirectional avalanche diode pair integrated into a single SC-70 package, with pins 1 and 3 serving as symmetrical anode/cathode terminals and pin 2 as common cathode. Its clamping action begins at ≥25 V in either polarity, limiting transients while maintaining <11 pF capacitance to avoid CAN FD signal distortion.

The NNCD27ST(0)-T1-AT is optimized for placement directly at CANH/CANL connector interfaces, where its 85 W surge rating (t_T = 10 μs) and 150 °C max junction temperature support sustained protection under repetitive ESD events without thermal runaway on standard FR-4 PCBs.

Key Specifications

Pinout & Package

Package: SC-70 (3-pin Super Mini Mold), dimensions 2.1 ± 0.1 mm × 1.25 ± 0.1 mm × 0.9 ± 0.1 mm, lead pitch 0.65 mm, Pb-free pure Sn plating.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ESD protection applications.

Compared with TPD2E001DRYR and SM712-TR, the NNCD27ST(0)-T1-AT delivers matched bidirectional clamping centered at 27 V, ultra-low 11 pF loading, and proven IEC61000-4-2 compliance-making it the only option qualified for production automotive CAN node designs requiring zero signal distortion and full ESD immunity certification.

Availability

NNCD27ST(0)-T1-AT is available at Aetrix Electronics and suitable for automotive ECU design, industrial CAN gateway development, and medical CAN sensor interface projects requiring stable component supply and long-term lifecycle assurance.

Supply support for NNCD27ST(0)-T1-AT 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

Renesas Electronics Corporation is a global semiconductor leader delivering microcontrollers, analog, power, and connectivity solutions for automotive, industrial, and IoT applications.

The NNCD27ST(0)-T1-AT belongs to Renesas' legacy ESD protection diode family developed specifically for Controller Area Network physical layer hardening in automotive and industrial control systems.

FAQ

What is the primary circuit role of the NNCD27ST(0)-T1-AT in a CAN bus system?

The NNCD27ST(0)-T1-AT serves as a bidirectional transient voltage suppressor placed directly at the CANH and CANL line entry points. It clamps ESD and fast transients to protect downstream CAN transceivers. Its symmetrical 25–31 V breakdown ensures equal protection for both polarities, and its 11 pF capacitance avoids signal integrity loss on 1 Mbps or CAN FD buses. The NNCD27ST(0)-T1-AT is not a signal conditioner or level shifter-it functions solely as a fail-safe shunt to ground during overvoltage events.

Does the NNCD27ST(0)-T1-AT meet automotive ESD immunity standards?

Yes, the NNCD27ST(0)-T1-AT is validated to IEC61000-4-2 Level 4: ±20 kV air discharge and ±15 kV contact discharge. This meets or exceeds OEM requirements for ECU-level ESD testing in passenger vehicles and commercial trucks. Its 85 W surge rating at 10 μs pulse width and 150 °C junction temperature rating ensure robust performance under repeated stress. The NNCD27ST(0)-T1-AT was originally qualified under NEC's "High Quality" grade for automotive and industrial safety-critical applications.

Can the NNCD27ST(0)-T1-AT be used in CAN FD networks operating at 5 Mbps?

Yes, the NNCD27ST(0)-T1-AT is suitable for CAN FD applications up to 5 Mbps due to its 11 pF typical junction capacitance and minimal parasitic inductance from the SC-70 package. Measurements confirm <0.5 ns added signal delay and no measurable eye diagram closure at 5 Mbps with proper PCB layout (short traces, ground plane coupling). The NNCD27ST(0)-T1-AT maintains signal fidelity because its clamping does not activate during normal bus operation-only during transients exceeding 25 V. Layout best practices remain essential.

What is the recommended PCB pad layout for the NNCD27ST(0)-T1-AT?

The recommended mount pad per Renesas datasheet D18881EJ1V0DS has dimensions: 0.65 mm (W) × 1.3 mm (L) for pins 1 and 3, and 0.6 mm (W) × 0.8 mm (L) for pin 2 (cathode), with 0.65 mm center-to-center spacing. Thermal relief to internal ground planes should use ≥4 spokes. Avoid solder mask dams between pins. The NNCD27ST(0)-T1-AT requires reflow profile compatible with Pb-free Sn plating (peak 260 °C, 10 s max). Proper pad geometry ensures mechanical reliability and optimal thermal dissipation during surge events.

Is the NNCD27ST(0)-T1-AT pin-compatible with other devices in the NNCDxxST family?

Yes, all NNCDxxST variants-including NNCD6.8ST, NNCD18ST, NNCD27ST(0)-T1-AT, and NNCD36ST-share identical SC-70 package dimensions, pinout (pin 1 = anode A, pin 2 = common cathode, pin 3 = anode B), and thermal pad layout. This allows direct substitution based on required breakdown voltage without PCB redesign. The NNCD27ST(0)-T1-AT replaces NNCD18ST or NNCD36ST when 27 V nominal clamping is needed for 24 V CAN systems with margin for load dump overshoot.