Datasheet Si8941/46/47 (Silicon Labs)

Si8941/46/47 Data Sheet
Isolated Delta-Sigma Modulator for Current Shunt Measurement
KEY FEATURES
The Si8941/46/47 is a galvanically isolated delta-sigma modulator which outputs a digital signal proportional to the voltage level at the input. The low-voltage differential input is ideal for meas- • Low voltage differential input uring voltage across a current shunt resistor or for any place where a sensor must be isolated • ±62.5 mV and ±250 mV options from the control system. Low noise, low error, and high precision ensure an accurate measure- • Modulator clock options ment of system current. • External clock up to 25 MHz (Si8941) The output of the Si8941/46/47 comes from a 2nd order delta-sigma modulator. The modulator • 10 MHz internal clock (Si8946) can be clocked either from an onboard oscillator (Si8946/47) or from an external clock (Si8941). The output is typically digitally filtered by a MCU or FPGA in the system. • 20 MHz internal clock (Si8947) • Typical input offset: ±40 µV The Si8941/46/47 isolated delta-sigma modulator utilizes Silicon Labs’ proprietary isolation • Typical gain error: ±0.1% technology. It supports up to 5.0 kVrms withstand voltage per UL1577. This technology enables • Excellent drift specifications higher performance, reduced variation with temperature and age, tighter part-to-part matching, • ±0.15 µV/°C typical offset drift and longer lifetimes compared to other isolation technologies. • ±14 ppm/°C typical gain drift
Applications:
• Typical 14-bit (ENOB) precision • Industrial, HEV and renewable energy inverters • High common-mode transient • AC, Brushless, and DC motor controls and drives immunity: 75 kV/µs • Typical SNR: 90 dB • Variable speed motor control in consumer white goods • Typical THD: –97 dB • Isolated switch mode and UPS power supplies • Typical nonlinearity: 0.002 • Automotive BMS and charging • Compact packages
Safety Approvals (pending):
• 8-pin wide body stretched SOIC • UL 1577 recognized • 8-pin narrow body SOIC • Up to 5000 Vrms for 1 minute • –40 to 125 °C • CSA component notice 5A approval • IEC 60950-1 (reinforced insulation) • VDE certification conformity • VDE0884 Part 10 (basic/reinforced insulation) • CQC certification approval • GB4943.1
Si894x
VDDA VDDB AIP CLK ACLK DSM AIN ADAT
Transmitter Receiver
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 2.1 Modulator 3. Current Sense Application 4. Electrical Specifications 4.1 Regulatory Information 4.2 Typical Operating Characteristics 5. 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