GXSC Analog-to-Digital Converter Replaces LTC2255 for Fiber Optic Sensing Applications

Fiber optic sensing technology detects and transmits external signals through optical fibers, enabling measurement of various physical quantities such as temperature, pressure, flow, displacement, and vibration. The operating principle of fiber optic sensors is based on the transmission characteristics of light waves. External signals modulate the light waves propagating within the fiber, thereby enabling signal detection and analysis. Offering advantages like electromagnetic interference immunity, high sensitivity, corrosion resistance, miniaturization, and flexibility, it finds extensive applications across multiple fields.

Fiber optic sensing detects changes in physical quantities like temperature, strain, and vibration through optical fibers, converting them into optical signals. These signals undergo photoelectric conversion and analog-to-digital conversion (ADC) to achieve precise quantification and analysis of the physical quantities. The GXSC 14-bit 125Msps single-channel low-power ADC meets the high-speed acquisition demands for weak optoelectronic signals in fiber optic sensing systems. It is suitable for various applications including distributed fiber sensing (DTS/DVS/DAS) and fiber Bragg grating sensing.

This GXSC ADC offers selectable rates of 125Msps or 105Msps and operates at low power with only 3V. Designed specifically for digitizing high-frequency, wide dynamic range signals, it is also well-suited for demanding imaging and communication applications. Its AC performance includes 72.3dB SNR and 85dB spur-free dynamic range (SFDR) for signals at the Nyquist frequency. DC specifications include ±1 LSB INL (typical) across the entire temperature range, ±0.5 LSB DNL (typical), and no missing codes. Conversion noise is exceptionally low at 1.3 LSB RMS.

The GXSC ADC provides a single-ended CLK input to control operation, with an optional clock duty cycle stabilizer enabling high performance at full speed and multiple clock duty cycle conditions. A separate output power supply allows driving 0.5V to 3.3V logic circuits. Key features include:

Performance comparable to the benchmark LTC2255 for seamless replacement

Unique ESD protection circuit design with measured ESD (HBM) >7000V (rated 4000V)

14-bit, 125Msps, single-channel, low-power A/D converter

Designed for digitizing high-frequency, wide dynamic range signals

3V (2.85V to 3.4V) single supply

Low power consumption: 280mW

No missing codes

Flexible input range: 1Vp-p to 2Vp-p

640MHz full-power bandwidth sampling and hold

Integrated clock duty cycle stabilizer

Supports shutdown and sleep modes

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