Skyworks Solutions Inc. SI8231BD-B-ISR

Overview

SI8231BD-B-ISR from Silicon Labs is a 0.5 A peak-output, isolated high-side/low-side gate driver with PWM input configuration, 5 kVRMS isolation (SOIC-16 wide-body package), 60 ns max propagation delay, and programmable dead time. It drives IGBTs/MOSFETs in half-bridge topologies for solar inverters and motor control systems.

For engineers reviewing the SI8231BD-B-ISR datasheet, SI8231BD-B-ISR pinout, SI8231BD-B-ISR application, or SI8231BD-B-ISR equivalent, this page delivers verified electrical specs, safety certifications (UL 1577, VDE 0884-5, CSA 5A), thermal derating data, and real-world design context for isolated gate drive selection.

Technical Context

The SI8231BD-B-ISR implements RF-based on/off keying across a silicon isolation barrier-replacing optocouplers with superior CMTI (>45 kV/µs), no startup initialization, and robust magnetic field immunity. Its single PWM input controls both outputs with internal overlap protection and resistor-programmable dead time (70–900 ns).

It features independent undervoltage lockout on input (VDDI UV+ = 4.0 V typ) and driver supplies (5/8/10/12.5 V selectable thresholds), TTL-compatible inputs with 450 mV hysteresis, and dual 24 V-rated output stages capable of sinking 0.5 A or sourcing 0.25 A per channel.

Key Specifications

Pinout & Package

SI8231BD-B-ISR uses a 16-pin wide-body SOIC package (WBSOIC-16) with 8.0 mm creepage/clearance, rated for 5 kVRMS isolation. Pin 1 is marked with dot; pin 1–8 form input side, pins 9–16 form isolated output side.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side/low-side isolated gate drive applications.

Compared with Si8231AD-B-ISR, SI8231BD-B-ISR provides 2× higher isolation voltage and wider creepage for medical/industrial safety compliance; versus UCC21520DW, it offers simpler PWM-only interface but lower drive strength - making it optimal for cost-sensitive, space-constrained 0.5 A half-bridge designs.

Availability

SI8231BD-B-ISR is available at Aetrix Electronics and suitable for solar inverters, industrial motor drives, and EV onboard chargers requiring stable component supply, long-term lifecycle support, and certified reinforced isolation.

Supply support for SI8231BD-B-ISR 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

Silicon Labs is a fabless semiconductor company specializing in precision timing, isolation, and mixed-signal ICs for industrial, automotive, and communications markets.

The Si823x family was designed specifically for high-reliability isolated gate driving in high-dv/dt power conversion systems - emphasizing CMTI performance, safety certification, and integration of dead time control.

FAQ

What is the maximum recommended switching frequency for SI8231BD-B-ISR?

The SI8231BD-B-ISR supports up to 8 MHz switching frequency per datasheet specifications. However, practical use in half-bridge configurations is typically limited to 500 kHz due to gate charge requirements and thermal constraints. At 350 kHz with 25 nC IGBTs and 22 Ω gate resistors, the SI8231BD-B-ISR remains within its 1.2 W power dissipation limit at 125 °C ambient.

Does SI8231BD-B-ISR require external components for dead time programming?

Yes, SI8231BD-B-ISR uses an external resistor connected to the DT pin to set dead time between 70 ns and 900 ns. A 100 kΩ resistor yields ~900 ns; a 6 kΩ resistor yields ~70 ns. The maximum allowed value is 220 kΩ. No capacitor or additional active components are required - simplifying layout and reducing BOM count.

Can SI8231BD-B-ISR drive SiC MOSFETs directly?

SI8231BD-B-ISR can drive low-to-mid-power SiC MOSFETs (Qg ≤ 25 nC) with appropriate gate resistors and 15–20 V VDDA/VDDB rails. Its 0.5 A sink capability supports turn-off of 1200 V SiC devices, but for high-power modules (>50 A), a gate driver with ≥4 A peak output (e.g., Si8234) is recommended. Always verify Miller clamp behavior and negative turn-off voltage requirements.

What safety certifications apply to SI8231BD-B-ISR?

SI8231BD-B-ISR holds UL 1577 (5000 Vrms), VDE 0884-5 (IEC 60747-5-5), CSA Component Notice 5A (IEC 60950-1/60601-1), and CQC GB4943.1 certifications. These cover reinforced insulation up to 600 Vrms working voltage and validate its use in medical, industrial, and grid-connected equipment where safety isolation is mandated.

How does the DISABLE pin function on SI8231BD-B-ISR?

The DISABLE pin (Pin 5) forces both outputs (VOA and VOB) low when driven high, overriding PWM input. When disabled, outputs settle to low within 60 ns. This feature enables safe shutdown during fault conditions (e.g., overtemperature or overcurrent). The pin is TTL-compatible and requires no pull-up; internal hysteresis prevents chatter during slow-rising control signals.