AD7679ASTZRL Equivalent & Substitute Parts

Part Overview

The AD7679ASTZRL is an 18-bit Analog to Digital Converter (ADC) manufactured by Analog Devices Inc., part of the PulSAR® series. This device features a single differential input with SAR (Successive Approximation Register) architecture and operates at a sampling rate of 570 kSPS. The component is housed in a 48-LQFP package (7x7mm) and is designed for applications requiring high-resolution analog signal acquisition with parallel and SPI interfaces.

The AD7679ASTZRL is currently classified as obsolete. Identifying equivalent and substitute parts is essential for maintaining design continuity, ensuring supply chain reliability, and supporting legacy system maintenance or redesigns.

Substiute Parts

AD7679ASTZRL

Analog Devices Inc.In Stock: 1229AD7679ASTZRL Datasheet

Current PartRFQ

AD7989-5BCPZ-R2

Analog Devices Inc.In Stock: 950AD7989-5BCPZ-R2 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AD7679ASTZRL is determined by the following critical parameters:

• Resolution: 18-bit conversion capability
• Architecture: SAR-based analog-to-digital conversion
• Input Configuration: Single differential input channel
• Sampling Rate: Minimum 500 kSPS to maintain performance envelope
• Supply Voltage Compatibility: Operating voltage ranges that support system integration
• Data Interface: SPI and DSP protocols for system communication
• Package Compatibility: Surface mount technology with thermal and electrical performance equivalence

The AD7989-5BCPZ-R2 qualifies as a substitute based on matching resolution, architecture, input type, and core data interfaces. However, differences in package form factor, supply voltage specifications, and sampling rate require careful evaluation for specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

Supply Voltage Consideration: The AD7679ASTZRL operates at 5V supply levels, while the AD7989-5BCPZ-R2 requires 2.375V to 2.625V supplies. Substitution requires voltage regulation or power supply redesign to accommodate the lower supply voltage of the AD7989-5BCPZ-R2.

Sampling Rate Trade-off: The AD7989-5BCPZ-R2 provides 500 kSPS sampling rate compared to the 570 kSPS of the AD7679ASTZRL. This 70 kSPS reduction may impact applications with strict Nyquist frequency requirements.

Data Interface Limitation: The AD7989-5BCPZ-R2 does not support parallel interface operation. Systems relying on parallel data communication must retain the AD7679ASTZRL or implement SPI/DSP-only architectures.

Package Form Factor: The AD7989-5BCPZ-R2 uses a compact 10-LFCSP package (3x3mm) versus the 48-LQFP (7x7mm) of the original part. PCB layout redesign is required for substitution.

Product Status and Compliance: The AD7989-5BCPZ-R2 is active production and ROHS3 compliant, providing long-term supply assurance and regulatory alignment for new designs or system updates.

Frequently Asked Questions (FAQ)

Q: Can the AD7989-5BCPZ-R2 directly replace the AD7679ASTZRL without circuit modifications?

A: No. The AD7989-5BCPZ-R2 requires different supply voltages (2.375V–2.625V versus 5V), lacks parallel interface support, and uses a different package footprint. Circuit redesign is necessary.

Q: What is the impact of the 70 kSPS sampling rate difference?

A: The AD7989-5BCPZ-R2 operates at 500 kSPS versus 570 kSPS for the AD7679ASTZRL. For applications with input signals below 250 kHz (Nyquist limit), this difference is negligible. Higher frequency applications may require evaluation of signal bandwidth requirements.

Q: Is the AD7989-5BCPZ-R2 suitable for legacy system maintenance?

A: The AD7989-5BCPZ-R2 is suitable only if the system can accommodate lower supply voltages, SPI/DSP-only communication, and compact package redesign. For drop-in replacement without modifications, alternative 18-bit SAR ADCs with 5V operation and parallel interface support should be evaluated.

Q: What are the thermal and reliability considerations for the smaller package?

A: The 10-LFCSP package (3x3mm) has reduced thermal mass compared to the 48-LQFP (7x7mm). Thermal management and PCB layout must be re-evaluated for applications with high power dissipation or stringent thermal requirements.

Q: Does the AD7989-5BCPZ-R2 support the same reference voltage options?

A: The AD7679ASTZRL supports both external and internal reference types. The AD7989-5BCPZ-R2 supports external reference only. Applications using internal reference must implement external reference circuitry.