AD7939BCP

Overview

The AD7939BCP is an 8-channel, 10-bit successive approximation register (SAR) analog-to-digital converter manufactured by Analog Devices Inc. It operates from a single 2.7 V to 5.25 V supply and supports throughput rates up to 1.5 MSPS. The device features a software-configurable channel sequencer that accommodates 8 single-ended, 4 fully differential, or 7 pseudo-differential input configurations. It includes an accurate on-chip 2.5 V reference with ±0.2% maximum accuracy at 25°C. The part utilizes a high-speed parallel interface compatible with 3 V or 5 V processor systems via the VDRIVE function. Key performance metrics include a SINAD of 61 dB minimum and power consumption as low as 6 mW at 1.5 MSPS with 3 V supplies.

Feature Summary

• Integrated channel sequencer for automated sequential conversion of multiple analog inputs
• Software-selectable analog input modes including single-ended, fully differential, and pseudo-differential configurations
• On-chip precision 2.5 V voltage reference with low temperature coefficient
• VDRIVE logic interface allowing direct connection to 3 V or 5 V microprocessors independent of analog supply

Applications

• Industrial process control data acquisition systems
• Portable instrumentation requiring low power consumption
• Battery-powered measurement devices
• Multi-channel signal monitoring in automation equipment

Procurement Notes

Verify the specific package variant against the datasheet outline dimensions, as the BC suffix typically denotes the LFCSP package while other suffixes may indicate TQFP. Confirm the operating temperature range matches the B version specification of -40°C to +85°C. Ensure the ordering code aligns with the required revision level and packaging format. Cross-reference the manufacturer's current product status to confirm availability and lifecycle stage before finalizing procurement plans.

Selection Notes

Select the AD7939BCP when eight analog channels are required within a compact footprint. Choose this component over the AD7938 if 10-bit resolution is sufficient, as it offers lower power dissipation and higher dynamic performance metrics like SINAD. Consider the internal sequencer capabilities for applications needing automated channel scanning without external controller overhead. Evaluate the VDRIVE pin requirements to ensure compatibility with the target digital logic levels.

Part Context

The AD7939 belongs to the AD7938/AD7939 family of high-speed, low-power multichannel ADCs from Analog Devices. This series shares a common architecture featuring a SAR core and a flexible input multiplexer. The AD7939 specifically provides 10-bit resolution, distinguishing it from the 12-bit AD7938. Both devices share identical pinouts and control registers, facilitating design flexibility across different resolution requirements.

Replacement Considerations

The AD7938BSUZ serves as a functional substitute offering 12-bit resolution with identical pinout and interface timing. For lower channel count applications, the AD7934 or AD7933 families provide similar performance with fewer inputs. Verify that any replacement maintains the 1.5 MSPS throughput rate and supports the required analog input configurations.