SI8921AB-ISR

Special Purpose Amplifiers Overview

The SI8921AB-ISR is an automotive-grade isolated analog amplifier from the Si8921 series, manufactured by Skyworks Solutions. It features a specified linear differential input range of ±250 mV and provides a differential analog output amplified by a gain of 8.2x. The device utilizes CMOS isolation technology to support up to 5.0 kVRMS withstand voltage per UL1577 standards. Key electrical characteristics include a typical signal delay of 0.8 µs, a bandwidth of 600 kHz, and a typical input offset voltage of ±0.40 µV. It operates within a temperature range of -40 °C to +125 °C.

Special Purpose Amplifiers Feature Summary

• Automotive-grade qualification with AEC-Q100 certification and AIAG-compliant PPAP documentation support.
• Galvanic isolation using proprietary CMOS technology for high common-mode transient immunity.
• Low-voltage differential input optimized for direct connection to current shunt resistors.
• Fail-safe output mode that activates upon loss of the primary-side supply voltage.

Special Purpose Amplifiers Applications

• Current shunt measurement in industrial inverters
• High-voltage electric vehicle (HEV) power systems
• Renewable energy inverter control circuits
• Automotive onboard chargers and battery management systems

Special Purpose Amplifiers Procurement Notes

Verify the specific ordering suffix 'ASR' against the manufacturer's official datasheet to confirm package type and reel specifications. Ensure the component meets the required automotive quality standards, including AEC-Q100 compliance and PPAP documentation availability. Confirm moisture sensitivity level ratings prior to soldering assembly to prevent damage during reflow processes.

Special Purpose Amplifiers Selection Notes

Select this component when a differential output is required for driving ADCs or subsequent processing stages. The ±250 mV input range accommodates higher resistance shunt values compared to lower-range variants. Verify that the system requires galvanic isolation exceeding standard low-voltage limits and benefits from the specific 0.8 µs signal delay characteristic for fast fault response.

Special Purpose Amplifiers Part Context

This part belongs to the Si8921/Si8922 family of isolated amplifiers designed for precise current sensing in noisy environments. Unlike the single-ended Si8922, the Si8921 variant provides a differential output, which aids in noise rejection. The 'A' designation indicates the ±250 mV input range, while 'B' typically denotes the ±62.5 mV range in other SKUs, though datasheet tables list Si8921B as ±250mV; verify exact mapping in the full ordering guide.

Special Purpose Amplifiers Replacement Considerations

SI8921AB-IS