Part A
AD977ARZ
Công ty 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 AD977ABR is a functionally compatible replacement candidate for the AD977ARZ, sharing the same 16-bit resolution, 100 kSPS sampling rate, and 20-pin SOIC package. The primary distinction is the grade specification, with the AD977ABR offering tighter INL and DNL performance, which should be validated against the target application's accuracy requirements.
Resolution
High match
Sampling Rate
High match
Package Type
High match
INL/DNL Grade
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 | AD977ABR | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 16 bit | Both converters provide the same 16-bit resolution, so quantization accuracy is equivalent. |
| Sampling Rate | 100 kSPS | 100 kSPS | Identical maximum throughput means both can handle the same signal bandwidth and update rate requirements. |
| Number of Input Channels | 1 (single-ended) | 1 (single-ended) | Same single-channel architecture allows direct functional substitution in the signal chain. |
| Interface Type | Serial (SPI/QSPI compatible) | Serial (SPI/QSPI 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 requirement means the existing power design can support either part without modification. |
| Package / Mounting | 20-lead SOIC (surface mount) | 20-lead SSOP (surface mount) | Different package footprints require PCB layout changes, affecting drop-in substitutability. |
| Operating Temperature Range | -40 °C to +85 °C (industrial) | -40 °C to +85 °C (industrial) | Both are rated for the industrial range, so environmental tolerance is equivalent for most applications. |
| INL (Integral Nonlinearity) | ±2.0 LSB max | ±3.0 LSB max | The ARZ grade offers tighter linearity, which matters for precision measurement accuracy. |
| DNL (Differential Nonlinearity) | ±1.0 LSB max | ±1.0 LSB max | Equal DNL guarantees no missing codes for both parts, preserving monotonicity performance. |
| Grade / Accuracy Class | A grade (higher precision) | B grade (standard precision) | The grade difference reflects tighter specs on the ARZ, which may be required for high-accuracy designs. |
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 | AD977ABR |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Part Status | Active | Obsolete |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 100k | 200k |
| 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 AD977ABR?
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 and packaging: the AD977ARZ is the RoHS-compliant version (Z suffix) of the A-grade device, while the AD977ABR is the non-RoHS B-grade version. The B grade offers tighter specifications, notably lower INL and DNL, compared with the A grade.
Are the AD977ARZ and AD977ABR pin-compatible?
Yes. Both devices are offered in the same 28-lead SOIC (R-28) package with identical pin functions, so they are pin-compatible. The difference lies in electrical grade and RoHS compliance, not the pinout.
What are the resolution and throughput of these converters?
Both the AD977ARZ and AD977ABR are 16-bit successive-approximation ADCs with a maximum throughput of 100 kSPS, as specified in the Analog Devices datasheet.
How do the INL specifications differ between the A and B grades?
Per the Analog Devices datasheet, the AD977A (A grade, including AD977ARZ) specifies a maximum INL of ±3.0 LSB, while the AD977B (B grade, including AD977ABR) specifies a maximum INL of ±2.0 LSB. The B grade therefore offers better linearity.
How do the DNL specifications differ between the two grades?
The datasheet specifies a maximum DNL of ±3.0 LSB for the AD977A grade (AD977ARZ) and ±1.0 LSB for the AD977B grade (AD977ABR), meaning the B grade provides better differential linearity.
Does the AD977ARZ meet RoHS requirements while the AD977ABR does not?
Yes. The "Z" suffix in AD977ARZ denotes a RoHS-compliant package, whereas the AD977ABR is the non-RoHS version. Designs requiring RoHS compliance should use the AD977ARZ.
What analog input range and reference configuration do these ADCs use?
Both devices accept a bipolar analog input range of ±10 V and use an external 2.5 V reference, as stated in the Analog Devices datasheet. The input range and reference requirements are identical across both grades.
Can the AD977ABR be substituted with the AD977ARZ in an existing design?
Because both parts share the same package, pinout, resolution, throughput, input range, and reference configuration, the AD977ARZ can generally serve as a drop-in replacement for the AD977ABR. However, the A grade has wider INL and DNL limits than the B grade, so the substitution should be validated against the system's accuracy requirements.