WFD22 - 22 bit / 1 Msps Waveform digitizer


  • 1 MHz sample rate with 22 bit resolution
  • Fully differential input with 10 ranges
  • 100MΩ low I-bias, 1MΩ Ultra-low noise input
  • 1.5ppm typical linearity
  • ±(25µV + 10ppm of range) absolute accuracy
  • Selectable filters to reduce out-of-band noise
  • -122dB THD typical (f-in=1kHz)
  • 105dB SNR typical (DC-500kHz)
  • Programmable DC-offset voltage
  • For ATX series hardware platform

The WFD22 is a 22 bit Waveform Digitizer for medium-speed / high resolution waveform capturing and analyzing. It combines superior dynamic performance with a very high DC accuracy.

The module features fully differential inputs to reduce common-mode level disturbances. It can also be used in Single Ended mode where an internal DC-offset source sets the midscale level. In this mode the negative input can be used as a GND Sense input, so the DC performance won’t be compromised due to ground currents.

The user can select between a 100MΩ low bias current input for highest absolute accuracy, or a 1MΩ ultra-low noise input for highest dynamic performance.

There are 10 input ranges from 0.425Vpp to 10.2Vpp, which allows easy adaptation to a wide range of Device Under Test output voltages.

A filter-bank with 3 Low Pass filters (40kHz, 250kHz and 500kHz) provides excellent signal conditioning resulting in lower noise and proper anti-aliasing.

Our proprietary technology combines four 20 bit ADCs to create an advanced 22 bit converter. This results in excellent SNR and linearity with a resolution down to 0.1µV. The large capture memory of 32M-word (96MB) allows capturing long waveforms. This can be very useful when a high number of averages is required.

All these features together result in the highest accuracy available when performing analog measurements. DAC linearity and dynamic performance measurements are a breeze with the WFD22 in the ATX7006 system.

Also applications like: Power meter testing, MRI amplifier test, Quantum effect research, etc. will benefit from the outstanding analog performance of the WFD22.


DC to 500kHz spectrum, 10kHz carrier, no filtering

wfd22 block

(conditions: after 1 hour warm-up, TA=25ºC, filter bypass unless otherwise mentioned)


Resolution 22 bit
Sample rate 0 - 1MHz
Pattern depth 32M words

Input characteristics

Input impedance / mode 100MOhm low bias current mode / 1MOhm low noise mode
Input configuration Differential / Single Ended (-Input to Gnd, Gnd-sense or DC offset)
Input ranges (Vpp) 0.425, 0.637, 0.850, 1.275, 1.70, 2.55, 3.40, 5.10, 6.80, 10.20
Input filters Bypass, 40kHz (4-pole Butterw.), 250kHz (5-pole Butterworth), 500kHz (7-pole elliptic)
Bandwidth -3dB (typical) 1.1MHz (5.10Vpp range)
0.1dB flatness (typical) 200kHz (5.10Vpp range)
Input Common mode range +/- 10.2V

Accuracy (DC-offset off, 100ksps)

Absolute accuracy, ranges 1.70-10.2Vp ±(25µV + 10ppm of range)
Absolute accuracy, ranges 0.425-1.275Vp ±(25µV + 15ppm of range)
Non Linearity error ±3ppm of range (1.5ppm typical)
Input bias current (typical) 1pA in 100MOhm mode / 50nA in 1MOhm mode

DC-offset source

Resolution 20-bit (10µV)
Voltage range -5.1V to +5.1V
DC-offset accuracy ±(10µV + 6ppm of value)
Non Linearity ±3ppm of range

Dynamic characteristics

(conditions: 1MOhm input mode, 1Msps, 500kHz filter on)

SNR (5Vpp, 1kHz input) 99dB (105dB typical)
SNR (5Vpp, 10kHz input) 97dB
SNR (5Vpp, 100kHz input) 93dB
SNR (1kHz input, A-weighted) 110dB (BW 20Hz - 20kHz)
THD (5Vpp, 1kHz input) -115dB (-122dB typical)
THD (5Vpp, 10kHz input) -110dB
THD (5Vpp, 100kHz input) -94dB
SFDR (5Vpp, 1kHz input) 112 dB
CMRR (typical) 110 dB

Clock & Trigger inputs

Input impedance > 1MOhm
Threshold level 3.3V CMOS/TTL (5V tolerant)