Datasheet Si8921/22 (Silicon Labs)

Si8921/22 Data Sheet
Isolated Amplifier for Current Shunt Measurement
KEY FEATURES
The Si8921/22 is a galvanically isolated analog amplifier. The low-voltage differential input is ideal for measuring voltage across a current shunt resistor or for any place where a sensor • Low voltage differential input must be isolated from the control system. The output is a differential analog signal amplified by • ±62.5 mV and ±250 mV options either 8.2x or 32.8x. • Low signal delay: 0.8 µs The very low signal delay of the Si8921/22 allows control systems to respond quickly to fault • Typical input offset: ±40 µV conditions or changes in load. Low offset and gain drift ensure that accuracy is maintained over • Typical gain error: ±0.1% the entire operating temperature range. Exceptionally high common-mode transient immunity • Excellent drift specifications means that the Si8921/22 delivers accurate measurements even in the presence of high-power • ±0.5 µV/°C typical offset drift switching as is found in motor drive systems and inverters. • –4 ppm/°C typical gain drift The Si8921/22 isolated amplifier utilizes Silicon Labs’ proprietary isolation technology. It sup- • Typical Nonlinearity: 0.003% full- scale ports up to 5.0 kVrms withstand voltage per UL1577. This technology enables higher perform- ance, reduced variation with temperature and age, tighter part-to-part matching, and longer life- • Typical SNR: 82 dB over 100 kHz bandwidth times compared to other isolation technologies. • Typical THD: –88 dB
Applications:
• High common-mode transient • Industrial, HEV and renewable energy inverters immunity: 75 kV/µs • AC, Brushless, and DC motor controls and drives • Compact packages • 8-pin wide body stretched SOIC • Variable speed motor control in consumer white goods • 8-pin narrow body SOIC • Isolated switch mode and UPS power supplies • –40 to 125 °C
Safety Approvals (pending):
• UL 1577 recognized • Up to 5000 Vrms for 1 minute • CSA component notice 5A approval • IEC 60950-1 (reinforced insulation) • VDE certification conformity • VDE0884 Part 10 (basic/reinforced insulation) • CQC certification approval • GB4943.1
Si8921 Si8922
VDDA VDDB VDDA VDDB OSC OSC AIP AOP AIP AO PWM PWM PWM PWM AIN AON AIN NC
Transmitter Receiver Transmitter Receiver
GNDA CMOS Isolation GNDB GNDA CMOS Isolation GNDB
silabs.com
| Building a more connected world. Preliminary Rev. 0.5 This information applies to a product under development. Its characteristics and specifications are subject to change without notice. Document Outline 1. Ordering Guide 2. System Overview 3. Current Sense Application 4. Electrical Specifications 4.1 Regulatory Information 4.2 Typical Operating Characteristics 5. Pin Descriptions 5.1 Si8921 Pin Descriptions 5.2 Si8922 Pin Descriptions 6. Packaging 6.1 Package Outline: 8-Pin Wide Body Stretched SOIC 6.2 Package Outline: 8-Pin Narrow Body SOIC 6.3 Land Pattern: 8-Pin Wide Body Stretched SOIC 6.4 Land Pattern: 8-Pin Narrow Body SOIC 6.5 Top Marking: 8-Pin Wide Body Stretched SOIC 6.6 Top Marking: 8-Pin Narrow Body SOIC 7. Revision History