Broadcom Limited ASSR-1520-302E

Overview

ASSR-1520-302E from Broadcom is a dual-channel, normally-off, solid-state SPST relay (Photo MOSFET) with optically isolated input and high-voltage MOSFET output stage. It delivers 1.0 A output current, 60 V output withstand voltage, 0.2 Ω typical on-resistance at 25°C, and operates across –40°C to +85°C for industrial control and data acquisition systems.

For engineers reviewing the ASSR-1520-302E datasheet, pinout, applications, or equivalent options, key selection criteria include its dual-channel 1 Form A EMR equivalence, gull-wing DIP-8 surface-mount package, 0.27 ms typical turn-on time, 0.04 ms typical turn-off time, and UL 3750 Vrms isolation rating.

Technical Context

The ASSR-1520-302E integrates an AlGaAs infrared LED input stage optically coupled to a high-speed photovoltaic diode array and driver circuit that controls two discrete high-voltage MOSFETs. Its dual-channel architecture enables independent switching of two isolated loads using a single 4-pin input side and 4-pin output side.

It functions as a bidirectional signal switch with CMOS-compatible input drive (3 mA min. turn-on current), supports AC/DC output configurations, and features transient immunity >1 kV/μs and input-to-output capacitance of 0.8 pF - critical for noise-sensitive measurement and medical instrumentation.

Key Specifications

Pinout & Package

ASSR-1520-302E uses an 8-pin DIP gull-wing surface-mount package (300-mil width), with pins 1–4 forming the input LED side and pins 5–8 forming the dual-channel output MOSFET side. The package complies with JEDEC J-STD-020 reflow profiles and supports automated assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar solid-state relay applications.

Compared with TLP3558A and VO3120, the ASSR-1520-302E offers superior speed (0.27 ms vs ≥0.35 ms), lower conduction loss (0.2 Ω vs ≥0.35 Ω), and native dual-channel integration in a gull-wing DIP-8 - delivering higher functional density and better thermal performance in space-constrained industrial controllers.

Availability

ASSR-1520-302E is available at Aetrix Electronics and suitable for industrial controls, factory automation, and data acquisition systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for ASSR-1520-302E 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

Broadcom Inc. is a global semiconductor leader specializing in infrastructure software, networking, and optoelectronics solutions for enterprise, industrial, and communications markets.

The ASSR-15XX series was designed specifically for high-current, high-reliability industrial switching - replacing electromechanical relays with solid-state alternatives offering longer lifetime, faster response, and enhanced noise immunity.

FAQ

What is the maximum output current rating for ASSR-1520-302E at 85°C ambient temperature?

The ASSR-1520-302E supports up to 0.8 A per channel at TA = 85°C, as defined by its derating curve (Figure 4). This value assumes proper PCB copper area (4-layer board) and IF = 10 mA drive. At 25°C, the rated current is 1.0 A per channel. Exceeding these limits risks junction temperature exceeding 125°C and permanent device degradation.

Does ASSR-1520-302E support AC load switching?

Yes, the ASSR-1520-302E supports AC/DC output connections. Its bidirectional MOSFET output structure allows switching of both polarities, making it suitable for 24 V AC control circuits and universal-input industrial sensors. However, peak AC voltage must remain within the 60 V withstand rating, and external snubbers may be needed for inductive AC loads.

What is the input LED forward voltage specification for ASSR-1520-302E at 5 mA drive current?

The ASSR-1520-302E has a typical forward voltage of 1.3 V at IF = 5 mA and 25°C, with a maximum of 1.65 V. This low VF enables direct interface with 3.3 V or 5 V CMOS logic outputs without series resistor recalculations, simplifying drive circuit design while maintaining reliable turn-on margin across temperature.

How is isolation verified for ASSR-1520-302E, and what safety standards does it meet?

The ASSR-1520-302E is UL recognized to 3750 Vrms for 1 minute per UL1577 and approved under CSA Component Acceptance Notice #5. Its isolation barrier is validated via dielectric withstand testing across shorted input pins (1–4) and shorted output pins (5–8), with minimum creepage (4.8 mm) and clearance (4.9 mm) distances ensuring compliance in industrial safety-critical designs.

Can ASSR-1520-302E replace electromechanical relays in high-cycle applications?

Yes - the ASSR-1520-302E is explicitly designed as a drop-in replacement for 2 Form A electromechanical relays. With no moving parts, it achieves >10⁹ operations versus ~10⁵–10⁷ for EMRs, eliminates contact bounce and arcing, and supports switching frequencies up to several kHz. Its 0.27 ms turn-on time enables precise timing control unattainable with mechanical counterparts.