Summary of ADS131M08 8-CHANNEL SIMULTANEOUS SAMPLING DELTA-SIGMA (ΔΣ) ADC
Texas Instruments' ADS131M08 is an 8-channel, 24-bit ΔΣ ADC designed for simultaneous sampling in energy metering and power metrology. It features a programmable gain amplifier (PGA) with gains up to 128, low power consumption of 6.0 mW, and integrated calibration registers to correct signal-chain errors. The device supports direct sensor interfacing via resistor dividers or transformers and includes a negative charge pump for sub-ground signals.
Parts used in the ADS131M08 Project:
- ADS131M08 8-channel ADC
- Resistor-divider network
- Power transformer
- Current transformer
- Rogowski coil
- Low-noise programmable gain amplifier (PGA)
- Internal voltage reference
- CRC communication interface
Texas Instruments’ 24-bit, 32 kSPS ADC is optimized for cost-sensitive applications that require simultaneous sampling
Texas Instruments’ ADS131M08 8-channel, simultaneously-sampling, 24-bit ΔΣ ADC offers wide dynamic range, low power, and energy-measurement-specific features. These features make the device ideal for energy metering, power metrology, and circuit breaker applications. The ADC inputs can be directly interfaced with a resistor-divider network or a power transformer to measure voltage or to a current transformer or a Rogowski coil to measure current.
The individual ADC channels can be independently configured depending on the sensor input. A low-noise programmable gain amplifier (PGA) provides gains ranging from 1 to 128 to amplify low-level signals. This device integrates channel-to-channel phase calibration and offset and gain calibration registers to help remove signal-chain errors.
Features
- Eight simultaneously sampling differential inputs
- Programmable data-rate up to 32 kSPS
- Programmable gain up to 128
- Noise performance:
- Dynamic ranges: 102 dB (gain = 1, 4 kSPS), 80 dB (gain = 64, 4 kSPS)
- High-impedance inputs for direct sensor connection:
- Input impedance for gains of 1, 2, and 4 (330 kΩ), 8, 16, 32, and 64 (1 MΩ)
- Programmable channel-to-channel phase delay calibration:
- 244 ns resolution, 8.192 MHz fCLKINTotal harmonic distortion: -100 dB
- Current-detect mode allows for extremely low power tamper detection
- Fast startup: first data within 0.5 ms of the supply ramp
- Integrated negative charge pump allows input signals below ground
- Crosstalk between channels: -120 dB
- Low-drift internal voltage reference
- CRC on communications and the register map
- Analog and digital supplies: 2.7 V to 3.6 V
- Low power consumption: 6.0 mW at 3 V AVDD and DVDD
- Package: 32-pin TQFP or 32-pin WQFN
- Operating temperature range: -40°C to +125°C
Read more: ADS131M08 8-CHANNEL SIMULTANEOUS SAMPLING DELTA-SIGMA (ΔΣ) ADC
- What applications is the ADS131M08 ideal for?
The device is ideal for energy metering, power metrology, and circuit breaker applications. - Can the ADC inputs be directly connected to sensors?
Yes, inputs can be directly interfaced with resistor-divider networks, power transformers, current transformers, or Rogowski coils. - How high can the programmable gain be set?
The low-noise programmable gain amplifier provides gains ranging from 1 to 128. - Does the device support phase calibration between channels?
Yes, it integrates channel-to-channel phase calibration with 244 ns resolution. - What is the startup time for data output?
The device offers fast startup with the first data available within 0.5 ms of the supply ramp. - How does the device handle input signals below ground?
An integrated negative charge pump allows input signals below ground. - What is the power consumption at 3 V supplies?
The low power consumption is 6.0 mW at 3 V AVDD and DVDD. - Does the device include error checking on communications?
Yes, it includes CRC on communications and the register map.
