1 Features

• Wideband or low-latency filter option

• Programmable data rate:

– Up to 512 kSPS (wideband filter)

– Up to 1.365 MSPS (low-latency filter)

– Up to 2.048 MSPS (partial wideband filter)

• Preset or custom coefficient FIR filter

• Custom biquad IIR filter

• Input range: ±VREF or ±2 VREF

• AC accuracy with dc precision:

– Dynamic range (200 kSPS): 111.5 dB, typical

– THD: –120 dB, typical

– INL: 0.9 ppm of FS, typical

– Offset drift: 50 nV/°C, typical

– Gain drift: 0.6 ppm/°C, typical

• Power-scalable architecture:

– Max-speed range: 512 kSPS (wideband filter)

– High-speed range: 400 kSPS (wideband filter)

– Mid-speed range: 200 kSPS (wideband filter)

– Low-speed range: 50 kSPS (wideband filter)

• Easy-drive buffered inputs

• Internal or external clock operation

2 Applications

• Test and measurement:

– Data acquisition (DAQ)

– Acoustics and dynamic strain gauges

• Factory automation and control:

– Vibration/condition monitoring

• Medical:

– Electroencephalograms (EEG)

• Grid infrastructure:

– Power quality analyzers

3 Description

The ADS127L21 is a 24-bit, delta-sigma (ΔΣ), analogto-

digital converter (ADC) featuring a programmable

digital filter with data rates up to 512 kSPS using

the wideband filter and up to 1365 kSPS using

the low-latency filter. The device offers an excellent

combination of ac performance and dc precision with

low power consumption.

Preset or custom infinite and finite impulse response

(IIR and FIR) digital filters provide standard or

customized response profiles, such as A-weighting

compensation. Wideband or low-latency filter modes

optimize ac-signal performance or data throughput of

dc signals, all in one device.

The device features an easy-drive signal and

reference inputs for reduced signal loading. The lowdrift

modulator achieves excellent dc precision with

low in-band noise for outstanding ac performance.

The power-scalable architecture provides four speed

ranges to optimize data rate, resolution, and power

consumption.

The serial interface features daisy-chain capability to

reduce the SPI I/O over an isolation barrier. Input

and output data and register memory are validated by

the optional cyclic-redundancy check (CRC) feature to

enhance operational reliability.

The small 3-mm × 3-mm WQFN package is designed

for space-limited applications. The device is fully

specified for operation over the –40°C to +125°C

temperature range.