Skyworks Solutions Inc. SI8235BB-C-IS1R

Overview

SI8235BB-C-IS1R from Silicon Laboratories is a dual-channel isolated gate driver IC with 4.0 A peak output current per channel, 5 kVRMS input-to-output isolation (SOIC-16 wide-body package), 60 ns max propagation delay, and operation from –40 to +125 °C. It serves as a high-reliability replacement for optocoupler-based gate drive in industrial inverters and motor control systems.

For engineers reviewing the SI8235BB-C-IS1R datasheet, SI8235BB-C-IS1R pinout, SI8235BB-C-IS1R application, or SI8235BB-C-IS1R equivalent, key selection criteria include its dual independent isolated outputs, programmable dead time capability, reinforced insulation certification (UL, VDE, CSA), 4.0 A sink/source drive strength, and compatibility with Si8236/Si8238 for thermally enhanced layouts.

Technical Context

The SI8235BB-C-IS1R implements RF-based on/off keying across a silicon isolation barrier-enabling robust noise immunity without startup initialization. Its dual-channel architecture supports fully independent input-to-output signal paths with no shared ground constraints, allowing each output to interface with separate floating power domains.

It features TTL-compatible inputs with 400 mV hysteresis, undervoltage lockout on both input (VDDI) and driver-side supplies (VDDA/VDDB), and internal overlap protection. Unlike HS/LS variants (e.g., Si8233), it lacks built-in dead-time logic but supports external dead-time insertion via resistor programming on the DT pin.

Key Specifications

Pinout & Package

SI8235BB-C-IS1R 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 reinforced insulation rating.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual isolated gate driver applications.

Compared with Si8236BB-C-IS1R, SI8235BB-C-IS1R offers identical electrical performance but higher thermal resistance-requiring careful heatsinking above 1 W dissipation. Versus ADuM4223BRIZ, SI8235BB-C-IS1R delivers superior isolation rating and integrated dead-time tuning, at the cost of slightly larger footprint and higher VDDI quiescent current.

Availability

SI8235BB-C-IS1R is available at Aetrix Electronics and suitable for motor control systems, industrial inverters, and isolated dc-dc power supplies requiring stable component supply, long-term lifecycle support, and certified reinforced insulation.

Supply support for SI8235BB-C-IS1R 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 Laboratories is a U.S.-based semiconductor company specializing in precision timing, isolation, and mixed-signal ICs for industrial, automotive, and communications markets.

The Si823x product line was designed to replace optocouplers in high-reliability gate drive applications-delivering higher speed, tighter timing matching, and certified safety isolation without LED aging or parameter drift.

FAQ

What is the maximum isolation voltage rating for SI8235BB-C-IS1R?

The SI8235BB-C-IS1R is rated for 5 kVRMS input-to-output isolation (1 minute, UL 1577), verified by production testing to 6.0 kVRMS. This rating applies specifically to the SOIC-16 wide-body package variant (IS1R suffix) and supports reinforced insulation per IEC 60950-1, IEC 60601-1, and VDE 0884-5 standards. The device achieves this via proprietary silicon isolation barrier technology-not transformer or capacitor-based coupling.

Does SI8235BB-C-IS1R support programmable dead time, and how is it configured?

Yes, SI8235BB-C-IS1R supports programmable dead time via an external resistor connected to the DT pin (Pin 12). With R_DT = 6 kΩ, dead time is ~70 ns; with R_DT = 100 kΩ, it reaches ~900 ns. This feature is implemented in hardware and does not require firmware or configuration registers. The SI8235BB-C-IS1R datasheet specifies the largest usable resistor as 220 kΩ, and the function operates independently of input logic state or enable status.

What are the absolute maximum ratings for VDDA and VDDB on SI8235BB-C-IS1R?

The absolute maximum rating for VDDA and VDDB on SI8235BB-C-IS1R is 30 V, as specified in Table 8 of the datasheet. However, functional operation is limited to 6.5–24 V per the Electrical Specifications table. Exceeding 24 V may cause excessive power dissipation or violate safety isolation margins. The device includes undervoltage lockout (UVLO) thresholds at 5 V, 8 V, 10 V, and 12.5 V-selectable via part number variant-but SI8235BB-C-IS1R defaults to the 12.5 V UVLO option.

Can SI8235BB-C-IS1R drive both N-channel and P-channel MOSFETs directly?

SI8235BB-C-IS1R is optimized for driving N-channel MOSFETs and IGBTs in high-side or low-side configurations. Its outputs are push-pull (not open-drain), with VOAL ≤ 0.04 V at 1 mA sink and VOA(H) ≥ VDDA – 0.04 V at –1 mA source. While it can sink 4.0 A and source 2.0 A, driving P-channel high-side switches requires inverted logic and level-shifting-making it less direct than N-channel use. For P-MOSFET gate drive, external level shifters or complementary driver pairing is recommended.

Is SI8235BB-C-IS1R pin-compatible with other Si823x family members like Si8230 or Si8233?

No, SI8235BB-C-IS1R is not pin-compatible with Si8230 or Si8233. Although all Si823x devices use the same SOIC-16 wide-body package, their pin functions differ significantly: SI8235BB-C-IS1R is a dual-driver (VIA/VIB → VOA/VOB), while Si8230/Si8233 are high-side/low-side drivers with dedicated HS/LS outputs and internal overlap logic. Pin mapping for ENABLE, DT, and output assignments differs across sub-families-PCB layout must match the exact variant's pinout table in Rev. 1.5 datasheet Section 5.