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 AD977BR is a higher-grade variant of the AD977ARZ, sharing the same 16-bit architecture, pinout, and package while offering improved linearity and temperature performance. It is a viable functional replacement candidate, though the tighter grade specifications should be validated against the target application's accuracy and operating-temperature requirements.
Resolution and Architecture
High match
Package and Pinout
High match
Accuracy Grade
Validation required
Operating Temperature Range
Validation required
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 | AD977BR | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 16 bit | Both converters provide 16-bit resolution, so quantization noise floor and LSB size are equivalent for signal-chain budgeting. |
| Sampling Rate | 100 kSPS | 100 kSPS | Identical maximum throughput means neither part limits the achievable Nyquist bandwidth or update rate in the application. |
| INL (Integral Nonlinearity) | ±2.0 LSB max | ±1.0 LSB max | The B-grade offers tighter linearity, which directly improves absolute accuracy and reduces distortion in precision measurement designs. |
| DNL (Differential Nonlinearity) | ±1.0 LSB max | ±1.0 LSB max | Guaranteed monotonicity and no missing codes depend on DNL; both grades meet the same specification here. |
| Input Type | Single-ended current input | Single-ended current input | Matching input topology allows the same analog front-end and drive circuitry to be reused without redesign. |
| Supply Voltage | 5 V (analog and digital) | 5 V (analog and digital) | Same supply rails mean the power tree and decoupling network remain compatible between the two parts. |
| Interface | Parallel (16-bit word) | Parallel (16-bit word) | Identical parallel output interface ensures the same digital host and timing scheme can be used for either device. |
| Package | 28-lead SOIC (R-28) | 28-lead SOIC (R-28) | Same package and pinout permit drop-in substitution on an existing PCB footprint. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Equivalent industrial temperature range means both parts suit the same environmental conditions. |
| Grade / Accuracy Class | A grade | B grade | The grade determines guaranteed linearity limits; the B grade is the higher-accuracy bin and may be required where tighter INL is specified. |
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 | AD977BR |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 100k | 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 | 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 |
Frequently asked questions
What are the key differences between the AD977ARZ and the AD977BR?
Both are 16-bit, 100 kSPS analog-to-digital converters from Analog Devices in a 28-lead SOIC package. The primary difference is the grade: the AD977ARZ is specified for a maximum integral nonlinearity (INL) of ±3 LSB, while the AD977BR is specified for a maximum INL of ±2 LSB. The BR grade also carries tighter differential nonlinearity (DNL) and offset/ gain error specifications than the ARZ grade.
Are the AD977ARZ and AD977BR pin-compatible and package-compatible?
Yes. Both devices are offered in the same 28-lead SOIC (RW-28) package with identical pin functions, so they are pin-compatible and can share the same PCB land pattern. The difference between the two part numbers is the performance grade, not the package or pinout.
Can the AD977BR be used as a drop-in replacement for the AD977ARZ?
Because the AD977BR is a higher-grade version of the same converter with tighter INL and DNL limits, it is generally a valid upgrade in circuits designed for the AD977ARZ, provided the board layout and external components meet the BR grade's requirements. The reverse substitution (ARZ in place of BR) is not recommended where the tighter BR specifications are required by the design.
What are the resolution and throughput specifications of the AD977ARZ and AD977BR?
Both parts are 16-bit successive-approximation ADCs with a maximum throughput of 100 kSPS. They operate from a single +5 V analog supply and include an on-chip 2.5 V reference, a sample-and-hold amplifier, and a parallel 16-bit interface.
Do the AD977ARZ and AD977BR differ in power consumption?
No. Both grades share the same core architecture and supply requirements, with a typical power dissipation of approximately 100 mW from a +5 V supply. Power consumption is not a differentiating parameter between the ARZ and BR grades.
What are the operating temperature ranges for the AD977ARZ and AD977BR?
Both the AD977ARZ and AD977BR are specified over the industrial temperature range of −40 °C to +85 °C. Temperature range is identical across the two grades.
Which grade should be selected for a design requiring tight linearity?
For applications where integral nonlinearity and differential nonlinearity are critical, the AD977BR is the appropriate choice because its maximum INL is ±2 LSB versus ±3 LSB for the AD977ARZ, and its DNL and offset/gain error limits are also tighter. The AD977ARZ is suitable where the looser ARZ-grade limits satisfy the system error budget.