FEATURES• 16-Bit Resolution
• SNR: 80.5dB min
• THD: –88dB max (AMC1203B)
• ±280mV Input Range with +5V Supply
• Internal 2.5V Reference Voltage: 1% Accuracy
• Gain Error: ±1% (AMC1203B)
• UL1577, IEC60747-5-2 (VDE0884, Rev. 2), and IEC61010-1 Approved
– Isolation: 4000V Working Voltage: 560V
– Transient Immunity: 15kV/μs
• Typical 25-Year Life at Rated Working Voltage (see Application Report SLLA197)
• Specified Temperature Range: –40°C to +105°C
APPLICATIONS• Shunt Based Current Sensing in:
– Motor Control
– Uninterruptible Power Supplies
– Power Inverters
– Industrial Process Control
DESCRIPTION
The AMC1203 is a 1-bit, 10MHz, isolated delta-sigma
(ΔΣ) modulator with an output buffer separated from
the input interface circuitry by a silicon dioxide (SiO2)
isolation barrier. This barrier provides galvanic
isolation of up to 4000VPEAK. Used in conjunction with
isolated power supplies, these devices prevent noise
currents on a data bus or other circuits from entering
the local ground and interfering with or damaging
sensitive circuitry.
The AMC1203 modulator operates from a +5V supply PEAK,
with a dynamic range of 95dB. The differential inputs
are ideal for direct connection to shunt resistors or
other low-level signal sources. With the appropriate
digital filter and modulator rate, the device can be
used to achieve 16-bit analog-to-digital (A/D)
conversion with no missing codes. An effective
resolution of 14 bits and an SNR of 85dB (typical)
can be maintained with a sinc3 filter with a decimation
ratio of 256.
The modulator output is translated to a balanced
signal and then transferred by the capacitive isolation
barrier. Across the isolation barrier, a differential
comparator receives the logic transition information,
and then sets or resets a flip-flop and the output
circuit accordingly.
The AMC1203 is available in SOP-8 gull-wing,
SOP-8, and SOIC-16 packages. The AMC1203 is
characterized for operation over the ambient
temperature range of –40°C to +105°C.

