Chipanalog CA-IS1305AM25W

CA-IS1305x series devices are a family of precision isolated sigma-delta (Σ-Δ) modulators optimized for shunt resistor-based current sensing or other small-signal measurement applications. The input current sense amplifier monitors the current flowing through the shunt (sense) resistor, and the sigma-delta modulator converts the analog input into a digital bitstream of 1s and 0s at a much higher frequency. The digital output stage of the CA-IS1305x provides an unencoded bitstream. The analog input side (high side) and digital output side (low side) are separated by a unique silicon oxide (SiO₂) capacitive isolation barrier, which provides up to 5kV RMS of galvanic isolation per UL1577 certification, with an isolation driver transmitting the modulator output across this barrier. In systems with different voltage domains, this isolation technique is commonly used to protect the low-voltage side from the high-voltage side in the event of any fault. These devices also feature a common-mode transient immunity of up to 150kV/μs, enabling efficient bitstream transmission in noisy environments. The ultra-low input voltage range (±250mV) of the CA-IS1305x devices allows the use of small sense resistors to reduce power consumption, while the extremely low gain error of 0.3% ensures measurement accuracy. The device family also features fail-safe outputs to support high-safety system designs. CA-IS1305x devices are specified to operate with clock inputs from 5MHz to 21MHz. The internal sigma-delta modulator, combined with an external digital decimation sinc³ filter, achieves a signal-to-noise ratio (SNR) of 85dB at 78.1Ksps. The CA-IS1305x series is specified over an operating temperature range of -40°C to +125°C and is available in a 16-pin wide-body SOIC package.

• Differential input voltage range: ±250mV
• Ultra-low input offset voltage and drift; input offset voltage ±150μV (max) at 25°C
• Low gain error and drift; gain error ±0.3% (max) at 25°C, gain drift ±40ppm/°C (max)
• Excellent AC performance; SNR: 85dB (typical), THD: -93dB (typical)
• 16-bit resolution, no missing codes
• Robust isolation barrier; long lifetime: >40 years, isolation rating up to 5000VRMS, typical CMTI ±150kV/μs
• Fault diagnostics for enhanced system safety
• Wide operating temperature range: -40°C to 125°C
• 16-pin wide-body SOIC package
• Safety certifications: VDE 0884-17 isolation certification, UL recognition per UL1577, IEC 61010-1:2010+A1 certification

• Industrial motor control and drives
• Uninterruptible power supplies (UPS)
• Isolated power supplies