1 Features
• 8-channel, 18-bit ADC with analog front-end:
– Dual, simultaneous sampling: 4 × 1 channels
– Constant 1-MΩ input impedance front-end
• Programmable analog input ranges:
– ±12 V, ±10 V, ±7 V, ±5 V, ±3.5 V, and ±2.5 V
– Single-ended and differential inputs
– ±12-V common-mode voltage range
– Input overvoltage protection: Up to ±18 V
• User-selectable analog input bandwidth:
– 21 kHz and 400 kHz
• Integrated low-drift precision references
– ADC reference: 4.096 V
– 2.5-V reference output for external circuits
• Excellent AC and DC performance at fullthroughput:
– DNL: ±0.3 LSB, INL: ±1.5 LSB
– SNR: 92.2 dB, THD: –112 dB
• Power supply:
– Analog and digital: 5 V and 1.8 V
– Digital interface: 1.2 V to 1.8 V
• Temperature range: –40°C to +125°C

2 Applications
• Semiconductor tests
• Battery tests
• Data acquisition (DAQ)

3 Description
The ADS981x is an 8-channel data acquisition (DAQ)
system based on a dual, simultaneous-sampling, 18-
bit successive approximation register (SAR) analogto-
digital converter (ADC). The ADS981x features a
complete analog front-end for each channel with an
input clamp protection circuit, 1-MΩ input impedance,
and a programmable gain amplifier (PGA) with
user-selectable bandwidth options. The high input
impedance allows direct connection with sensors and
transformers, thus eliminating the need for external
driver circuits. The ADS981x can be configured to
accept unipolar or bipolar inputs with up to a ±12-V
common-mode voltage.
The device also features a 4.096-V reference for
the ADC and a 2.5-V reference output for use with
external circuits. A digital interface supporting 1.2-V
to 1.8-V operation enables the ADS981x to be used
without external voltage level translators.