ADC0838CCWMX

Analog To Digital Converters (ADC) Overview

The ADC0838CCWMX is an 8-bit successive approximation analog-to-digital converter (ADC) manufactured by Texas Instruments. It features a software-configurable multiplexer supporting up to eight input channels, which can be configured for single-ended, differential, or pseudo-differential operation. The device operates on a single 5 VDC supply with a voltage range of 4.5 V to 6.3 V and consumes a maximum power of 15 mW. It utilizes a TI MICROWIRE-compatible serial interface for data exchange. The component is housed in a 20-pin SOIC package and supports an operating temperature range from 0°C to +70°C.

Analog To Digital Converters (ADC) Feature Summary

• 8-Bit SAR Architecture: Provides high-speed conversion with a typical time of 32 μs and a clock frequency range of 10 kHz to 400 kHz.
• Multiplexer Options: Supports 8-channel input with configurable single-ended, differential, or pseudo-differential modes via software addressing.
• Serial Interface: Features a TI MICROWIRE-compatible serial I/O that allows direct connection to COPS family processors or standard microprocessors.
• Shunt Regulator: Includes internal zener diodes allowing operation with high-voltage supplies through the V+ pin.

Analog To Digital Converters (ADC) Applications

• Industrial process control systems requiring multi-channel signal acquisition.
• Data acquisition systems utilizing remote sensors with serial digital data links.
• Microprocessor peripherals where low pin count and noise immunity are required.
• Battery-powered instrumentation benefiting from low power consumption and ratiometric operation.

Analog To Digital Converters (ADC) Procurement Notes

Verify the specific suffix 'CCWMX' against the manufacturer's current product status, as older variants may have different availability or lead times. Confirm that the tape-and-reel packaging matches the production requirements. Ensure the ordering documentation explicitly references the SNAS531B datasheet to validate the electrical specifications and pinout configuration.

Analog To Digital Converters (ADC) Selection Notes

Select this component when an 8-bit resolution and up to eight analog inputs are required within a compact 20-pin surface-mount package. It is suitable for applications needing flexible input configurations, including differential pairs or pseudo-differential modes referenced to a common potential. Ensure the system clock frequency remains between 10 kHz and 400 kHz and that the supply voltage stays within the 4.5 V to 6.3 V range.

Analog To Digital Converters (ADC) Part Context

The ADC0838CCWMX belongs to the ADC0831-N series, which includes variants with varying channel counts (1, 2, 4, and 8). While the ADC0831, ADC0832, and ADC0834 share similar architectures, the ADC0838 specifically provides the 8-channel multiplexer capability. This series is designed to replace older parallel ADCs by offering serial communication capabilities without increasing the package footprint.

Analog To Digital Converters (ADC) Replacement Considerations

Direct replacements include other members of the ADC0831-N family such as the ADC0834N or ADC0832N if fewer channels are acceptable. For legacy non-N versions, check for compatibility with the original ADC0838, noting differences in manufacturing processes. Verify that any substitute maintains the same 20-pin SOIC package and MICROWIRE interface timing requirements.

Analog To Digital Converters (ADC) FAQ

How does the ADC0838 handle differential inputs?

The ADC0838 allows adjacent channel pairs to be configured as differential inputs. The polarity of the pair can be selected via the MUX addressing word, allowing either channel to serve as the positive or negative input.

What is the function of the V+ pin?

The V+ pin connects to an internal zener diode that acts as a shunt regulator. This allows the device to operate from higher voltage supplies while maintaining the internal logic and reference voltages at safe levels relative to ground.

Can the ADC0838 output data in LSB-first format?

Yes, the ADC0838 supports both MSB-first and LSB-first output formats. The SE (Sign/End) line controls this behavior; holding it high outputs MSB-first, while pulling it low initiates the LSB-first data stream.