AD7939BCPZ-REEL7

Overview

The AD7939BCPZ-REEL7 is a high-speed, low-power 10-bit successive approximation register (SAR) analog-to-digital converter manufactured by Analog Devices Inc. It features eight software-configurable analog input channels and an integrated channel sequencer. The device operates on a single power supply ranging from 2.7 V to 5.25 V and achieves throughput rates up to 1.5 MSPS. It includes an accurate on-chip 2.5 V reference and supports differential, pseudo-differential, or single-ended inputs. The component utilizes a high-speed parallel interface with word/byte modes and is housed in a 32-lead LFCSP package.

Feature Summary

• Eight analog input channels with a programmable channel sequencer for sequential conversion.
• Software-selectable analog input configurations including single-ended, fully differential, and pseudo-differential modes.
• Integrated accurate 2.5 V internal voltage reference with external overdrive capability.
• High-speed parallel digital interface compatible with 3 V or 5 V processor systems via the VDRIVE function.

Applications

• Industrial process control data acquisition systems
• Portable instrumentation requiring low power consumption
• Battery-powered measurement devices

Procurement Notes

Verify that the ordering suffix REEL7 corresponds to the tape-and-reel packaging format required for automated surface-mount assembly. Confirm the B version meets the specified commercial temperature range of -40°C to +85°C. Ensure the LFCSP-32 package dimensions align with the PCB footprint design guidelines provided in the datasheet.

Selection Notes

Select this model when a 10-bit resolution is sufficient for the application, as opposed to the 12-bit AD7938 variant. Consider the AD7939 for designs requiring lower power dissipation at equivalent speeds compared to higher-resolution counterparts. Verify that the 1.5 MSPS throughput rate satisfies the system bandwidth requirements.

Part Context

This component belongs to the AD7938/AD7939 family of multichannel ADCs. It shares the same physical package, pinout, and core architecture as the AD7938, differing primarily in resolution. The AD7939 provides 10-bit accuracy while maintaining the same 1.5 MSPS speed and eight-channel multiplexing capabilities.

Replacement Considerations

The AD7939BSUZ serves as a direct functional replacement offering identical specifications in a TQFP-32 package. For applications requiring higher resolution, the AD7938BCPZ-REEL7 provides 12-bit performance within the same form factor.

FAQ

How does the VDRIVE pin affect the digital interface?

The VDRIVE pin sets the logic voltage levels for the parallel interface, allowing it to connect directly to 3 V or 5 V processor systems independently of the main analog supply voltage (VDD).

What is the maximum power consumption at full speed?

Maximum power dissipation is 6 mW when operating at 1.5 MSPS with a 3 V supply, and 13.5 mW with a 5 V supply.

Can the internal reference be bypassed?

Yes, the VREFIN/VREFOUT pin can be overdriven by an external reference signal ranging from 0.1 V to VDD to replace the internal 2.5 V reference.