Nexperia USA Inc. BZA420A,165

Overview

BZA420A from Nexperia is a quadruple ESD transient voltage suppressor diode in SOT457 (SC-74) package, configured as four independent cathodes with shared anodes. It delivers 20 V working voltage (V_Z = 19–21 V at I_Z = 1 mA), clamps to ≤28 V at 0.7 A peak pulse current, and provides >8 kV ESD immunity per IEC 61000-4-2. It is used for high-density I/O line protection in compact interface circuits.

For engineers reviewing the BZA420A datasheet, BZA420A pinout, BZA420A application, or BZA420A equivalent, key selection criteria include common-anode quad-channel layout, low 14 pF capacitance at 15 V reverse bias, 125 Ω differential resistance, 19.6 W peak pulse power handling, and SOT457 footprint compatibility with space-constrained PCB designs.

Technical Context

The BZA420A integrates four monolithic Zener-based TVS diodes in a single SOT457 package with shared anode terminals (pins 2 and 5), enabling simultaneous suppression of four signal lines without cross-coupling. Its non-clamping range spans −0.5 V to 20 V, and it operates within a junction temperature range of −65 °C to +150 °C.

Clamping behavior is defined by peak reverse current (I_ZSM = 0.7 A) and corresponding V_ZSM = 28 V under 1 ms square pulse, supported by thermal resistance R_th(j-s) = 125 K/W and total power dissipation P_tot = 720 mW at T_s = 60 °C.

Key Specifications

Pinout & Package

SOT457 (SC-74) surface-mount package: six-lead plastic package with gull-wing leads, 0.95 mm pitch, 3.1 mm × 2.7 mm body size, and 1.1 mm max height. Pin 1 index located at top-left corner when viewed from top with marking "Z0" visible.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ESDA6V1-4U and TPD4E001DPYR, the BZA420A uniquely balances 20 V working voltage, 28 V clamping, and 14 pF capacitance-making it optimal for legacy and mixed-signal systems requiring robust 20 V-level transient suppression in standard SOT457 layouts.

Availability

BZA420A is available at Aetrix Electronics and suitable for computer peripherals, medical signal ports, audio/video I/O interfaces, and microprocessor bus protection requiring stable component supply across long-lifecycle industrial programs.

Supply support for BZA420A 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 high-volume production of discrete semiconductors, with expertise in ESD protection, logic, and PowerMOS devices for automotive, industrial, and consumer markets.

The BZA420A belongs to Nexperia's Standard Products ESD Protection portfolio, engineered specifically for cost-sensitive, space-constrained applications demanding certified IEC 61000-4-2 immunity without sacrificing signal fidelity.

FAQ

What is the correct PCB layout practice for minimizing clamping voltage in BZA420A applications?

Minimize series inductance by placing the BZA420A within 2 mm of the protected connector, using short direct traces to ground, avoiding shared return paths, and maximizing local ground plane area under the device. Keep cathode-to-connector and anode-to-ground trace lengths as short as possible to reduce V = L·di/dt overshoot during fast ESD pulses.

Can BZA420A be used to protect bidirectional data lines like I²C or SMBus?

Yes - its common-anode configuration allows each cathode to clamp positive transients to ground while the inherent diode junction blocks negative excursions beyond −0.5 V. For full bidirectional protection, pair with a complementary device or verify system-level negative transient tolerance, as the BZA420A does not actively clamp negative voltages below −0.5 V.

How does the dual-common-anode structure (pins 2 and 5) affect circuit design?

Pins 2 and 5 are electrically isolated internal anodes, allowing two independent suppression groups (cathodes 1+2 and cathodes 3+4). This enables separation of sensitive analog and noisy digital signal domains, prevents ground bounce coupling, and supports split-reference or isolated ground architectures without external isolation components.

Is BZA420A compliant with RoHS and REACH regulations?

Yes - BZA420A is manufactured by Nexperia in accordance with EU RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006. The SOT457 package uses lead-free terminations and halogen-free molding compound, with full material declarations available via Nexperia's product compliance portal.