Skyworks Solutions Inc. SI8231AB-B-ISR

Overview

SI8231AB-B-ISR from Silicon Labs is a 0.5 A peak-output, PWM-input, high-side/low-side isolated gate driver with 5 kVRMS input-to-output isolation, 60 ns max propagation delay, and programmable dead time. It operates from 4.5–5.5 V input supply and 6.5–24 V driver supplies, targeting IGBT/MOSFET drive in solar inverters and motor control systems.

For engineers reviewing the SI8231AB-B-ISR datasheet, SI8231AB-B-ISR pinout, SI8231AB-B-ISR application, or SI8231AB-B-ISR equivalent, key selection criteria include its PWM-input architecture, overlap protection, 45 kV/µs CMTI, –40 to +125 °C operation, and SOIC-16 wide-body package with reinforced insulation per UL1577, VDE 0884-5, and IEC 60950-1.

Technical Context

The SI8231AB-B-ISR implements RF-based on/off keying across a silicon isolation barrier for robust noise immunity and zero initialization latency. Its single PWM input controls both high-side and low-side outputs with internal logic enforcing non-overlapping switching via programmable dead time (70–900 ns) and overlap protection.

It features independent undervoltage lockout (UVLO) on input (4.0 V typ) and driver supplies (5–12.5 V selectable), TTL-compatible inputs with 450 mV hysteresis, and dual 0.5 A output stages capable of sinking 0.5 A and sourcing 0.25 A per channel into capacitive loads up to 200 pF.

Key Specifications

Pinout & Package

SI8231AB-B-ISR is housed in a RoHS-compliant SOIC-16 wide-body package (10.3 mm × 10.3 mm, 2.65 mm height) with creepage/clearance ≥8.0 mm and 5 kVRMS isolation rating.

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 and UCC21520DW, SI8231AB-B-ISR offers optimal balance of 5 V UVLO compatibility, hardware-enforced overlap protection, and SOIC-16 wide-body 5 kVRMS isolation - ideal for cost-sensitive industrial inverters requiring robust shoot-through prevention without firmware dependency.

Availability

SI8231AB-B-ISR is available at Aetrix Electronics and suitable for motor control systems, solar inverters, and industrial UPS requiring stable component supply, long-term lifecycle support, and certified reinforced isolation.

Supply support for SI8231AB-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 product line delivers high-speed, high-CMTI isolated gate drivers using proprietary RF-based silicon isolation - engineered specifically for reliability-critical power conversion topologies including half-bridges, three-phase inverters, and resonant LLC converters.

FAQ

What is the input voltage range for SI8231AB-B-ISR?

The SI8231AB-B-ISR accepts an input supply voltage (VDDI) of 4.5 V to 5.5 V. This range aligns with standard 5 V logic systems and ensures stable operation of the internal RF transmitter and digital logic. The device incorporates undervoltage lockout with a typical turn-on threshold of 4.0 V and hysteresis of 250 mV, preventing erratic behavior during power-up or brownout conditions. SI8231AB-B-ISR must not be operated outside this specified VDDI range to maintain guaranteed performance and safety certification compliance.

Does SI8231AB-B-ISR support programmable dead time?

Yes, SI8231AB-B-ISR supports hardware-programmable dead time via an external resistor (RDT) connected to the DT pin. The dead time is adjustable from 70 ns to 900 ns depending on RDT value (6 kΩ to 100 kΩ), enabling precise shoot-through prevention without MCU intervention. This feature is implemented in silicon and active only in high-side/low-side configurations like SI8231AB-B-ISR - not in dual-driver variants. SI8231AB-B-ISR's overlap protection logic enforces minimum non-overlap regardless of RDT setting.

What isolation rating does SI8231AB-B-ISR provide?

SI8231AB-B-ISR provides 5 kVRMS input-to-output isolation per UL1577, validated by production testing at 6.0 kVRMS for 1 second. It achieves reinforced insulation per IEC 60950-1, VDE 0884-5, and CSA Component Notice 5A, with minimum creepage and clearance of 8.0 mm in its SOIC-16 wide-body package. This rating applies specifically to the WB SOIC-16 variant (e.g., SI8231AB-B-ISR), not narrow-body or LGA versions. SI8231AB-B-ISR is certified for working voltages up to 600 VRMS in reinforced insulation applications.

Can SI8231AB-B-ISR drive both high-side and low-side switches simultaneously?

SI8231AB-B-ISR drives high-side (VOA) and low-side (VOB) outputs from a single PWM input, but never simultaneously in an overlapping manner. Its internal logic enforces strict non-overlap via hardware overlap protection and programmable dead time - ensuring one output turns off before the other turns on. This prevents shoot-through in half-bridge configurations. SI8231AB-B-ISR does not support independent control of each output; it is designed exclusively for complementary PWM-driven topologies where timing coordination is handled in silicon, not by external logic.

What is the maximum switching frequency supported by SI8231AB-B-ISR?

SI8231AB-B-ISR supports switching frequencies up to 8 MHz, enabled by its 60 ns maximum propagation delay and ≤5.6 ns pulse width distortion. This specification assumes CL = 200 pF load and operation within rated supply and temperature ranges. At higher frequencies, layout parasitics and gate charge requirements of the driven FET become limiting factors - not the driver itself. SI8231AB-B-ISR's 45 kV/µs CMTI and fast rise/fall times (<20 ns) ensure clean edge integrity even at multi-MHz rates in noisy power stage environments.