MXD1604
High-precision 16-bit SAR ADC with 4 differential channels, 500kSPS sampling, and extended temperature range.
Product Overview
Description
The MXD1604 is a high-performance 16-bit successive approximation register (SAR) analog-to-digital converter featuring four differential input channels.
With a sampling rate of 500kSPS and excellent DC accuracy (INL: +/- 1 LSB), this ADC is ideal for multi-channel sensor monitoring in aerospace and defense systems.
The device operates from a single 5V supply, includes an internal reference, and is available in hermetic ceramic packages for harsh environments.
Product Series
MXD
Primary Application
Satellite sensor systems
Key Features
- 16-bit resolution with no missing codes
- 500kSPS sampling rate per channel
- 4 differential input channels
- Internal 2.5V reference with 10ppm/°C drift
- Single 5V supply operation
- SPI-compatible serial interface
- Extended temperature range -55°C to +125°C
- Radiation tolerance option 50krad(Si)
- Hermetic ceramic packages available
Specifications
| Resolution | 16-bit |
|---|---|
| Sampling Rate | 500 kSPS |
| Channels | 4 differential |
| INL | +/- 1 LSB |
| SNR | 92 dB |
| Supply Voltage | 5V |
| Interface | SPI |
| Temperature Range | -55°C to +125°C |
| Radiation Tolerance | 50 krad(Si) optional |
| Package | CERDIP-28, QFP-32 |
Applications
Satellite sensor systems
Sensor signal conditioning
Military avionics
Electronic system design
Industrial process control
Industrial automation and control
Power monitoring systems
Electronic system design
Test and measurement equipment
Data acquisition and conversion
Medical instrumentation
Medical electronics
FAE Expert Insights
"The MXD1604 is an excellent choice for aerospace multi-channel data acquisition systems. In my experience supporting satellite payload designs, the 500kSPS sampling rate provides good throughput for most sensor monitoring applications while maintaining excellent DC accuracy. The radiation-tolerant version has been successfully used in LEO satellite missions with total dose requirements up to 50krad(Si). One key consideration for space applications is the internal reference - while convenient, external reference may be preferred for highest accuracy across temperature. The SPI interface is straightforward to implement with most space-qualified microcontrollers. For hermetic packaging, I recommend the CERDIP-28 for through-hole military boards or QFP-32 for surface-mount designs. The 4-channel architecture reduces system complexity compared to using multiple single-channel converters. I've seen this part used successfully in satellite power management systems, attitude control sensors, and telemetry acquisition."
Excellent multi-channel ADC for aerospace data acquisition with radiation tolerance
— Dr. Zhang Wei, BeiLuo
Frequently Asked Questions
What is the radiation tolerance of MXD1604?
MXD1604 is available in two versions: standard grade rated for -55°C to +125°C without radiation tolerance testing, and radiation-tolerant (RT) version tested to 50krad(Si) total ionizing dose (TID). The RT version undergoes radiation lot acceptance testing (RLAT) per MIL-STD-883 Method 1019. Single event effects (SEE) characterization is also available for the RT version. For missions requiring higher radiation tolerance, contact Mxtronics for 100krad(Si) options. Radiation test reports are provided with each RT lot.
Select RT version for space applications. Standard grade is sufficient for military/industrial without radiation.
How do I interface MXD1604 with my microcontroller?
MXD1604 uses standard SPI interface with CS (chip select), SCLK (serial clock), DIN (data in), and DOUT (data out) signals. Interface timing is compatible with most microcontrollers including radiation-tolerant SPARC and ARM processors used in space applications. SPI clock frequency up to 20MHz supports full throughput. Conversion is initiated by CS falling edge, and data is clocked out MSB first. For multi-channel scanning, use the internal sequencer or manually select channels via SPI commands. Reference code is available for common space-qualified microcontrollers.
Use standard SPI interface at up to 20MHz. Reference code available for space-qualified MCUs.
What is the best input driver circuit for MXD1604?
For optimal performance with MXD1604, use a low-noise op-amp (like MXA358) in unity-gain buffer configuration to drive the ADC input. Add a low-pass RC filter (typically 100Ω + 1nF) at the ADC input to limit bandwidth and reduce noise. The filter cutoff should be below half the sampling rate to prevent aliasing. For differential inputs, use a fully differential amplifier or two single-ended buffers with matched components. Keep traces short and use ground planes to minimize noise pickup. For high-impedance sensors, consider the op-amp's input bias current.
Use op-amp buffer with RC filter. Keep traces short and matched for differential inputs.
How do I calculate the effective number of bits (ENOB)?
ENOB is calculated from the measured SNR: ENOB = (SNR - 1.76) / 6.02. For MXD1604 with 92dB SNR, ENOB = (92 - 1.76) / 6.02 = 15.0 bits. This is the actual resolution achieved considering noise, not just the theoretical 16 bits. ENOB varies with input frequency and should be measured at your signal frequency of interest. Higher ENOB indicates better dynamic performance. For DC signals, use SINAD instead of SNR for ENOB calculation. Mxtronics provides typical ENOB vs frequency curves in the datasheet.
Calculate ENOB from SNR measurement. Consider ENOB at your operating frequency, not just DC.
What reference voltage should I use for highest accuracy?
MXD1604 includes an internal 2.5V reference with 10ppm/°C drift, suitable for most applications. For highest accuracy across temperature, use an external precision reference like MXR432 with 5ppm/°C drift. External reference also allows ratiometric measurement where sensor excitation and ADC reference use the same voltage, canceling out reference drift. For multi-channel systems, external reference ensures all channels use identical reference voltage. Connect external reference to REF pin and disable internal reference via SPI command.
Use internal reference for simplicity. Use external reference for highest accuracy or ratiometric measurement.