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