SI8921BB-IS

Special Purpose Amplifiers Overview

The Skyworks SI8921BB-IS is a galvanically isolated analog amplifier designed for current shunt measurement. It features a differential input with a specified linear range of ±250 mV and provides a differential output amplified by a gain of 8.2x. The device utilizes CMOS isolation technology to achieve a typical common-mode transient immunity of 75 kV/µs and an amplifier bandwidth of 600 kHz. It operates on dual power supplies ranging from 3 V to 5.5 V, consuming approximately 4.6 mA of supply current. The component is housed in an 8-pin wide-body stretched SOIC package and supports an operating temperature range from -40 °C to +125 °C.

Special Purpose Amplifiers Feature Summary

• Galvanic isolation via proprietary CMOS technology supporting up to 5.0 kVRMS withstand voltage per UL1577
• Low signal delay of 0.8 µs enabling rapid control system response to fault conditions
• Fail-safe output mode that activates upon loss of the high-voltage-side supply voltage
• High common-mode transient immunity of 75 kV/µs for accurate measurements in high-power switching environments

Special Purpose Amplifiers Applications

• Industrial, HEV, and renewable energy inverters
• AC, brushless, and DC motor controls and drives
• Isolated switch mode and UPS power supplies
• Automotive onboard chargers and battery management systems

Special Purpose Amplifiers Procurement Notes

Verify the specific ordering suffix to confirm the package type and insulation rating. The -IS suffix indicates a standard commercial grade part in an 8-pin wide-body stretched SOIC package. Ensure compliance with moisture sensitivity level requirements during storage and soldering assembly. Confirm that the selected variant meets the necessary safety regulatory approvals for your target application region.

Special Purpose Amplifiers Selection Notes

Select this component when a differential output is required for connection to a differential ADC or subsequent processing stage. The ±250 mV input range is suitable for higher resistance shunt measurements compared to the ±62.5 mV option. Consider the 8.2x fixed gain for applications where the signal amplitude fits within the 2.05 V full-scale output requirement. Evaluate the thermal characteristics if operating near the upper temperature limits.

Special Purpose Amplifiers Part Context

The SI8921BB-IS belongs to the Si8921/Si8922 family of isolated amplifiers manufactured by Skyworks Solutions. This series is engineered specifically for measuring voltage across current shunt resistors in high-noise environments. The Si8921 variant distinguishes itself by providing a differential analog output, whereas the Si8922 offers a single-ended output. Both share the same underlying isolation architecture and electrical performance specifications.

Special Purpose Amplifiers Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.