Catalog
Isolated Sigma-Delta Modulator
Key Features
• 20 MHz maximum external clock rate
• Second-order modulator
• 16 bits, no missing codes
• ±2 LSB INL typical at 16 bits
• 1 µV/°C typical offset drift
• On-board digital isolator
• On-board reference
• ±250 mV analog input range
• Low power operation: 17 mA typical at 5.5 V
• −40°C to +125°C operating range
• 16-lead SOIC package
• Internal clock version: AD7400A
• Safety and regulatory approvalsUL 1577VISO= 5000 V rms for 1 minuteIEC / CSA 62368-1IEC / CSA 61010-1DIN EN IEC 60747-17 (VDE 0884-17)VIORM= 645 V peak
• UL 1577VISO= 5000 V rms for 1 minute
• VISO= 5000 V rms for 1 minute
• IEC / CSA 62368-1
• IEC / CSA 61010-1
• DIN EN IEC 60747-17 (VDE 0884-17)VIORM= 645 V peak
• VIORM= 645 V peak
• Qualified for Automotive Applications
Description
AI
The AD7401A is a second-order, sigma-delta (Σ-Δ) modulator that converts an analog input signal into a high speed, 1-bit data stream with on-chip digital isolation based on the Analog Devices, Inc.,iCoupler®technology. The AD7401A operates from a 5 V power supply and accepts a pseudo-differential input signal of ±250 mV (±320 mV full scale). The analog input is continuously sampled by the analog modulator, eliminating the need for external sample-and-hold circuitry. The input information is contained in the output stream as a density of ones with a data rate of up to 20 MHz. The original information can be reconstructed with an appropriate digital filter. The serial I/O can use a 5 V or a 3.3 V supply (VDD2).The serial interface is digitally isolated. High speed CMOS, combined with Analog Devices, Inc.,iCoupler®technology, means the on-chip isolation provides outstanding performance characteristics, superior to alternatives such as optocoupler devices. The device contains an on-chip reference. The AD7401A is offered in a 16-lead SOIC and has an operating temperature range of −40°C to +125°C.ApplicationsAC motor controlsShunt current monitoringData acquisition systemsAnalog-to-digital and opto-isolator replacements
