MAX156ACWI+

Analog To Digital Converters (ADC) Overview

The MAX156ACWI+ is an 8-bit, 4-channel analog-to-digital converter (ADC) featuring simultaneous track-and-hold inputs and a 2.5V internal reference. It operates from a single +5V supply or dual ±5V supplies, supporting unipolar and bipolar input ranges in both single-ended and differential configurations. The device utilizes a successive approximation architecture with a 3.6µs conversion time per channel and stores results in an internal 8x8 RAM. It accepts external clock frequencies up to 5MHz and provides a bidirectional parallel interface for data access and configuration.

Analog To Digital Converters (ADC) Feature Summary

• Simultaneous sampling across all four channels eliminates timing skew between input samples.
• Integrated 2.5V voltage reference reduces component count and simplifies board layout.
• Internal 8x8 RAM allows sequential storage of conversion results for multiple channels.
• Flexible I/O mode enables dynamic configuration of channel types and conversion modes.

Analog To Digital Converters (ADC) Applications

• Phase-sensitive data acquisition systems
• Vibration analysis and waveform monitoring
• DSP-based analog input interfaces
• Portable data loggers

Analog To Digital Converters (ADC) Procurement Notes

Verify the specific suffix 'ACWI+' against official documentation to confirm temperature range and package type. Ensure the ordering code matches the required industrial specifications before procurement. Cross-reference the manufacturer's latest datasheet to validate current production status and availability constraints.

Analog To Digital Converters (ADC) Selection Notes

Select this component when simultaneous multi-channel sampling is critical to prevent phase errors. The 8-bit resolution suits applications requiring moderate accuracy with high throughput. Consider the 2.5V internal reference limitation; use external references if higher precision or different voltage ranges are necessary for the target application.

Analog To Digital Converters (ADC) Part Context

This part belongs to the MAX155/MAX156 family of high-speed multichannel ADCs. While the MAX155 offers eight channels, the MAX156 variant provides four channels in a similar form factor. Both share identical core architectures, including the SAR engine and simultaneous track-and-hold functionality, differing primarily in channel count and pin assignments.

Analog To Digital Converters (ADC) Replacement Considerations

Direct functional replacements within the same family include the MAX155 series for expanded channel counts. Verify pin compatibility and software register mapping when substituting components. Consult the manufacturer's recommended products list for newer generations that may offer improved performance metrics.

Analog To Digital Converters (ADC) FAQ

How does the MAX156 handle simultaneous sampling?

Each of the four analog input channels has its own dedicated track-and-hold amplifier. All amplifiers sample their respective inputs at the exact same instant upon the falling edge of the WR signal, ensuring zero timing skew between channels.

Can the MAX156 operate with bipolar inputs?

Yes. By connecting the VSS pin to -5V and configuring the BIP bit in the control register, the device supports bipolar input ranges from -VREF to +VREF. In standard single-supply operation, it supports unipolar ranges from 0V to VREF.

What is the purpose of the INH bit in the configuration register?

The INH (Inhibit) bit prevents the start of a conversion when the WR signal goes high. This allows the microprocessor to update the multiplexer configuration or access RAM locations without triggering an unwanted conversion cycle.