ADS127L01 Analog-to-Digital Converter

By Texas Instruments 144

ADS127L01 Analog-to-Digital Converter

Texas Instruments' ADS127L01 is a 24-bit, delta-sigma (ΔΣ), analog-to-digital converter (ADC) with data rates up to 512 kSPS. This device offers a unique combination of excellent DC accuracy and outstanding AC performance. The high-order, chopper-stabilized modulator achieves very low drift with low in-band noise. The on-chip decimation filter suppresses modulator out-of-band noise. In addition to a low-latency filter, the ADS127L01 provides multiple wideband filters with less than ±0.00004 dB of ripple and an option for -116 dB stop-band attenuation at the Nyquist rate.

Traditionally, industrial delta-sigma ADCs that offer good drift performance use digital filters with large passband droop. As a result, industrial delta-sigma ADCs have limited signal bandwidth and are mostly suited for DC measurements. High-resolution ADCs in audio applications offer larger usable bandwidths, but the offset and drift specifications are significantly weaker than industrial counterparts. The ADS127L01 combines these converters, providing high-precision industrial measurement with excellent DC and AC specifications over an extended industrial temperature range of -40°C to 125°C.

A variety of operating modes allow for optimization of speed, resolution, and power. A programmable serial interface with one of three options (SPI, frame-sync slave, or frame-sync master) provides convenient interfacing across isolation barriers to microcontrollers or digital signal processors (DSPs).

  • Data rates: up to 512 kSPS
  • AC performance:
    • Passband: up to 230 kHz
    • SNR: up to 115.5 dB (at OSR 256)
    • THD: -126 dB (LP and VLP modes)
  • DC accuracy:
    • Offset drift: 1.5 µV/°C
    • Gain drift: 0.2 ppm/°C
  • Operating modes:
    • HR: 111 dB SNR (128 kSPS at 26 mW)
    • LP: 108 dB SNR (128 kSPS at 15 mW)
    • VLP: 105 dB SNR (128 kSPS at 9 mW)
  • Digital filter options:
    • Low-latency filter:
      • Sinc frequency response 
    • Wideband 1 filter: 
      • (0.45 to 0.55) × fDATA transition band
    • Wideband 2 filter:
      • (0.40 to 0.50) × fDATA transition band
  • SPI™ or frame-sync serial interface
    • Daisy-chain compatible
  • Analog supply: 2.7 V to 3.6 V
  • Digital supply: 1.7 V to 3.6 V
  • Operating temperature: -40°C to 125°C