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 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.

• 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: 4000VPEAK, 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

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