GENERAL DESCRIPTION

The AD7400A1 is a second-order, Σ-Δ modulator that converts

an analog input signal into a high speed, 1-bit data stream with on-chip digital isolation based on Analog Devices, Inc., iCoupler® technology. The AD7400A operates from a 5 V power supply and accepts a differential input signal of ±250 mV (±320 mV

full-scale). The analog input is sampled continuously 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 10 MHz.

The original information can be reconstructed with an appropriate

digital filter. The serial I/O can use a 5 V or a 3 V supply (VDD2).

The serial interface is digitally isolated. High speed CMOS,

combined with monolithic air core transformer technology, means the on-chip isolation provides outstanding performance characteristics superior to alternatives such as optocoupler devices. The part contains an on-chip reference and has an

operating temperature range of −40°C to +125°C. The AD7400A

is offered in a 16-lead SOIC package.

FEATURES 10 MHz clock rate Second-order modulator

16 bits, no missing codes

±2 LSB INL typical at 16 bits 1.5 μV/°C typical offset drift On-board digital isolator On-board reference ±250 mV analog input range Low power operation: 15.5 mA typical at 5.5 V −40°C to +125°C operating range

16-lead SOIC package

AD7401A, external clock version in 16-lead SOIC

Safety and regulatory approvals UL recognition 5000 V rms for 1 minute per UL 1577 CSA Component Acceptance Notice #5A VDE Certificate of Conformity DIN V VDE V 0884-10 (VDE V 0884-10):2006-12

VIORM = 891 V peak

APPLICATIONS

AC motor controls

Shunt current monitoring

Data acquisition systems Analog-to-digital and opto-isolator replacements