SI8921BD-AS4R

Special Purpose Amplifiers Overview

The Skyworks SI8921BD-AS4R is an automotive-grade isolated analog amplifier featuring a differential input and output. It provides a specified linear input range of ±250 mV with a nominal gain of 8.2x, resulting in a full-scale output of 2.05 V. The device operates on a supply voltage between 3 V and 5.5 V, consuming approximately 4.6 mA of current. It utilizes CMOS isolation technology to support up to 5.0 kVRMS withstand voltage per UL1577. Key performance metrics include a typical signal delay of 0.8 µs, a bandwidth of 600 kHz, and high common-mode transient immunity of 75 kV/µs.

Special Purpose Amplifiers Feature Summary

• Automotive-grade qualification supporting AEC-Q100 standards and AIAG-compliant PPAP documentation.
• Galvanic isolation barrier utilizing proprietary CMOS technology for robust signal transmission.
• Fail-safe output mechanism that activates upon loss of the primary-side supply voltage.
• Low-voltage differential input architecture optimized for direct connection to current shunt resistors.

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 suffix configuration against the manufacturer's ordering guide to ensure correct insulation ratings and package dimensions. Confirm that the selected variant meets the required automotive quality standards and compliance certifications for the target application environment. Cross-reference the datasheet specifications with system requirements before finalizing procurement decisions.

Special Purpose Amplifiers Selection Notes

Select this component when a differential output is required for precise current sensing applications. The ±250 mV input range accommodates higher resistance shunts compared to lower-range variants. Ensure the design supports separate power supplies for the input and output sides to maintain galvanic isolation integrity across the semiconductor barrier.

Special Purpose Amplifiers Part Context

This part belongs to the Si8921/Si8922 family of isolated amplifiers designed for high-performance current sensing. The 'B' designation indicates the ±250 mV input range option, while 'D' specifies the 5.0 kVRMS insulation rating. The 'AS4R' suffix denotes the wide-body SOIC-8 package format and reel-based shipping configuration.

Special Purpose Amplifiers Replacement Considerations

The SI8921AD-AS4R serves as a functional substitute within the same series, offering identical packaging but differing in its specified linear input range of ±62.5 mV rather than ±250 mV. Designers must verify that the alternative input range aligns with their specific shunt resistor values and signal levels.