NXP Semiconductors BZA418A,165

Overview

BZA418A,165 from Nexperia is a quadruple ESD transient voltage suppressor diode in SOT457 (SC-74) package with common anode configuration, 18 V working voltage (V_Z = 17.1–18.9 V at I_Z = 1 mA), 27 V clamping voltage at 0.7 A peak pulse current, and 48 pF capacitance at 0 V bias - used for ESD protection of four independent signal lines in computer interfaces and microprocessor buses.

For engineers reviewing the BZA418A,165 datasheet, BZA418A,165 pinout, BZA418A,165 application, or BZA418A,165 equivalent, key selection criteria include common-anode quad-channel layout, non-clamping range (−0.5 to 18 V), 19.6 W peak reverse power dissipation at 1 ms, low differential resistance (125 Ω), and 14 pF capacitance at 13 V reverse bias for high-speed data line compatibility.

Technical Context

The BZA418A,165 integrates four monolithic Zener-based ESD suppression diodes sharing a common anode terminal, enabling compact protection of parallel signal paths without discrete component duplication. Its design targets fast transient response to IEC 1000-4-2 Level 4 (±8 kV contact discharge) while maintaining low capacitance across operating voltage range.

Thermal performance is defined by junction-to-soldering-point thermal resistance of 125 K/W and total power dissipation derating above 60 °C. Electrical behavior includes temperature coefficient of working voltage (14.4 mV/K) and reverse leakage ≤75 nA at 14 V, supporting stable operation in industrial ambient conditions.

Key Specifications

Pinout & Package

SOT457 (SC-74) surface-mount package: 6-pin plastic leaded package with gull-wing leads, 3.1 mm × 2.7 mm body size, 0.95 mm pitch, and 1.1 mm max height - optimized for automated placement and reflow soldering in high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ESDA6V1-4W6 and CM1224-04SO, the BZA418A,165 uniquely balances 18 V working voltage, 27 V clamping, and 14 pF at 13 V - making it optimal for mixed-voltage systems like microprocessor buses where overvoltage margin and signal integrity must coexist.

Availability

BZA418A,165 is available at Aetrix Electronics and suitable for industrial I/O modules, medical keypad interfaces, and microprocessor data bus protection requiring stable component supply and long-term lifecycle assurance.

Supply support for BZA418A,165 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

Nexperia is a global leader in discrete, logic, and PowerMOS semiconductors, formed in 2017 from the former NXP Standard Products division, with focus on automotive, industrial, computing, consumer, and wearable markets.

The BZA418A,165 belongs to Nexperia's ESD protection portfolio designed specifically for high-reliability, multi-line transient suppression in space-constrained PCBs - emphasizing low capacitance, precise voltage thresholds, and IEC 61000-4-2 compliance.

FAQ

What is the maximum clamping voltage of the BZA418A,165 under ESD stress?

The BZA418A,165 exhibits a maximum clamping voltage of 27 V at a non-repetitive peak reverse current (I_ZSM) of 0.7 A with 1 ms pulse duration. This value is measured per diode under standardized test conditions and defines the upper voltage limit imposed on protected signal lines during an ESD event. The BZA418A,165 maintains this clamping performance across its specified operating temperature range.

Does the BZA418A,165 support bidirectional ESD protection?

Yes, the BZA418A,165 provides bidirectional ESD protection through its common-anode configuration: each cathode-to-anode path clamps positive transients, while the inherent diode junction structure also conducts negative transients via forward bias into the anode. This enables full ±8 kV IEC 61000-4-2 compliance without external polarity components. The BZA418A,165 achieves this using monolithic integration rather than back-to-back discrete diodes.

What is the recommended PCB layout practice for the BZA418A,165?

Place the BZA418A,165 within 5 mm of the protected connector or IC pin, minimize trace length between cathodes and signal lines, route both anode pins (pins 2 and 5) directly to a low-inductance ground plane using multiple vias, and avoid parallel routing with unprotected traces. These practices reduce parasitic inductance that would otherwise increase clamping voltage (V = L·di/dt). The BZA418A,165's performance is highly dependent on such layout discipline.

Can the BZA418A,165 be used for 5 V logic line protection?

The BZA418A,165 is not recommended for 5 V logic protection because its 18 V working voltage (V_Z = 17.1–18.9 V) exceeds typical 5 V rail tolerances, resulting in no clamping action until transients exceed ~27 V - well beyond safe limits for 5 V ICs. For 5 V applications, select a device like ESDA6V1-4W6 with 6.1 V V_Z. The BZA418A,165 is engineered for 18 V systems such as microprocessor buses and industrial I/O.

What is the thermal resistance specification for the BZA418A,165?

The BZA418A,165 has a junction-to-soldering-point thermal resistance (R_{th j-s}) of 125 K/W, measured with one or more diodes loaded. This parameter governs temperature rise under power dissipation and informs derating curves: total power dissipation drops linearly from 720 mW at 60 °C soldering point temperature to zero at 150 °C. The BZA418A,165's thermal design assumes proper copper pour and via thermal relief per Nexperia's SOT457 layout guidelines.