Part A
AD977ARZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7094 PCS
- Package
- SOIC-20
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD977ARZ is a functionally compatible replacement candidate for the AD977AR, differing only in package construction and qualification grade while preserving identical core converter architecture, resolution, and interface characteristics. Validation of the specific grade and package requirements is recommended before substitution in qualified designs.
Resolution and Architecture
High match
Package Type
High match
Qualification Grade
Validation required
Interface and Pinout
High match
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD977ARZ | AD977AR | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 16 bit | Both converters provide the same 16-bit resolution, so accuracy and quantization behavior are equivalent. |
| Sampling Rate | 100 kSPS | 100 kSPS | Identical maximum throughput means either part supports the same signal bandwidth and system timing. |
| Number of Input Channels | 1 (single-ended) | 1 (single-ended) | Same single-channel architecture allows direct substitution in the signal chain. |
| Interface Type | Serial (SPI/QSPI/MICROWIRE compatible) | Serial (SPI/QSPI/MICROWIRE compatible) | Matching serial interface ensures the same digital host connection and firmware can be reused. |
| Supply Voltage | 5 V (analog and digital) | 5 V (analog and digital) | Same supply requirements mean no power rail redesign is needed when swapping parts. |
| Reference Type | Internal | Internal | Both include an internal reference, so external reference circuitry is not required for either. |
| Package / Mounting | 28-Lead SOIC (surface mount) | 28-Lead SOIC (surface mount) | Identical package and footprint allow drop-in board replacement without layout changes. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C (industrial) | Temperature grade affects reliability margins in harsh environments; verify the exact grade marking for the target application. |
| RoHS / Lead-Free Status | RoHS compliant, lead-free | Contains lead (non-RoHS) | The Z suffix denotes lead-free/RoHS compliance, which matters for regulatory compliance and solder process compatibility. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD977ARZ | AD977AR |
|---|---|---|
| Part Status | Active | Obsolete |
| Number of Bits | 16 | 16 |
| Sampling Rate (Per Second) | - | 100k |
| Number of Inputs | 1 | 1 |
| Input Type | Single Ended | Single Ended |
| Data Interface | SPI | SPI |
| Configuration | ADC | ADC |
| Number of A / D Converters | - | 1 |
| Architecture | SAR | SAR |
| Reference Type | External, Internal | External, Internal |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 5V | 5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | - | Surface Mount |
| Base Product Number | - | AD977 |
| Sampling Rate(Per Second) | 100k | - |
| Number of A/D Converters | 1 | - |
Frequently asked questions
What is the difference between the AD977ARZ and the AD977AR?
The AD977ARZ and AD977AR are both 16-bit, 100 kSPS analog-to-digital converters from Analog Devices. The primary difference is the package and ordering suffix: the AD977ARZ is supplied in a lead-free, RoHS-compliant 28-lead SOIC (R-28) package, while the AD977AR is the non-RoHS version of the same 28-lead SOIC package. Both share the same core specifications, including 16-bit resolution, 100 kSPS throughput, and a 5 V supply.
Are the AD977ARZ and AD977AR functionally interchangeable?
Yes, the two parts are functionally identical and share the same die and electrical specifications. The only difference is the RoHS/lead-free compliance of the package. In a design that does not require RoHS compliance, either part can be used; for RoHS-compliant assemblies, the AD977ARZ should be selected.
What are the key specifications of the AD977ARZ and AD977AR?
Both devices are 16-bit successive-approximation ADCs with a maximum throughput of 100 kSPS. They operate from a single 5 V supply, feature a serial interface, and are specified for the industrial temperature range of -40°C to +85°C. They are available in a 28-lead SOIC package.
Do the AD977ARZ and AD977AR differ in pinout or package dimensions?
No. Both parts use the same 28-lead SOIC (R-28) package with identical pinout and package dimensions. The only difference is the lead finish and RoHS compliance designation indicated by the "Z" suffix on the AD977ARZ.
Which part should be used for a new RoHS-compliant design?
The AD977ARZ should be used for new designs requiring RoHS compliance, as it is the lead-free, RoHS-compliant version. The AD977AR is the non-RoHS variant and is generally not recommended for new RoHS-restricted assemblies.
Are the AD977ARZ and AD977AR still in production?
Both the AD977ARZ and AD977AR are listed in Analog Devices' product documentation as part of the AD977 family. Designers should verify current production and lifecycle status directly with Analog Devices or an authorized distributor before committing to a design, as lifecycle status can change.