Nexperia USA Inc. BZA420A,125

Overview

BZA420A from Nexperia is a quadruple ESD transient voltage suppressor diode in SOT457 (SC-74) package, configured as four cathodes sharing a common anode. It provides 20 V working voltage, 28 V clamping at 0.7 A peak pulse, 48 pF capacitance at 0 V, <100 nA reverse leakage at 15 V, and 19.6 W peak power dissipation for IEC 61000-4-2 Level 4 ESD protection on high-speed data lines.

For engineers reviewing the BZA420A datasheet, BZA420A pinout, BZA420A application, or BZA420A equivalent, this device is selected for compact multi-line ESD hardening in space-constrained interfaces where low capacitance, precise clamping, and common-anode routing efficiency are critical - especially in USB, keyboard, and parallel bus protection.

Technical Context

The BZA420A integrates four monolithic Zener-based TVS diodes in a single SOT457 package with shared anode connection, enabling simultaneous suppression of four independent signal lines without inter-channel coupling. Its non-clamping range spans −0.5 V to 20 V, and it delivers stable clamping at 28 V under 0.7 A 1 ms pulses per diode.

Thermal design centers on junction-to-solder-point resistance (125 K/W), with total power dissipation derated above 60 °C and maximum junction temperature rated to +150 °C. Diode capacitance drops from 48 pF at 0 V to 14 pF at 15 V reverse bias - a key enabler for high-frequency signal integrity preservation.

Key Specifications

Pinout & Package

SOT457 (SC-74) is a 6-pin plastic surface-mount package measuring 3.1 mm × 2.7 mm × 1.3 mm, with gull-wing leads and pin 1 index marker. Thermal resistance from junction to solder point is 125 K/W when one or more diodes are loaded.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ESDA6V1SC6 and TPD4E001DQAR, the BZA420A uniquely balances 20 V operation, 48 pF capacitance, and true quad common-anode topology - making it optimal for legacy parallel interfaces, industrial control I/O, and mixed-voltage systems requiring coordinated multi-line clamping without layout complexity.

Availability

BZA420A is available at Aetrix Electronics and suitable for computer interface protection, microprocessor bus hardening, audio/video equipment I/O, and medical device front-panel interfaces 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, logic devices, and PowerMOS transistors - spun off from NXP's Standard Products division in 2017.

The BZA420A belongs to Nexperia's ESD protection portfolio, engineered specifically for cost-sensitive, high-reliability applications in computing, industrial control, and consumer electronics where compact multi-line transient suppression is essential.

FAQ

What is the maximum allowable continuous forward current for the BZA420A?

The BZA420A supports up to 100 mA continuous forward current (I_F) at solder point temperature (T_s) = 60 °C. This rating assumes all four diodes share the load equally and thermal coupling to PCB copper is maintained. Exceeding this limit risks junction overheating beyond the +150 °C absolute maximum, potentially degrading clamping consistency over time.

Can the BZA420A be used for bidirectional signal line protection?

Yes - the BZA420A operates bidirectionally due to its common-anode configuration: each cathode-to-anode junction behaves as a Zener clamp for positive transients, while the inherent PN junction conducts for negative transients. This enables full ±8 kV IEC 61000-4-2 protection without external polarity components or series resistors.

How does PCB layout affect the clamping performance of the BZA420A?

PCB layout critically impacts clamping voltage: parasitic inductance in the anode or cathode traces adds L·di/dt voltage overshoot. To maintain the specified 28 V clamping, keep anode and cathode trace lengths under 3 mm, place the device within 5 mm of the protected connector, and route the anode directly to a solid ground plane - not through vias or narrow traces.

Is the BZA420A RoHS compliant and halogen-free?

Yes - the BZA420A meets RoHS Directive 2011/65/EU and is halogen-free per IEC 61249-2-21. Nexperia confirms compliance in its official product change notifications (PCN #170012), with lead-free matte tin termination and molded compound free of brominated flame retardants and antimony trioxide.