Part A
AD977ABRS
ADI公司
- Lifecycle
- Active
- Stock
- 1992 件
- Package
- SSOP-28
- Series
- 資料獲取-模數轉換器（ADC）
Replacement verdict
Compatible functional replacement candidate
The AD977ABRS and AD977BRS are functionally equivalent 16-bit successive-approximation ADCs sharing the same pinout, package, and core architecture, with the AD977ABRS offering a tighter grade-level linearity specification. The AD977BRS can serve as a functional substitute for the AD977ABRS in most designs, though the relaxed INL and DNL tolerances of the B grade should be validated against the application's accuracy budget before committing to volume production.
Resolution and Architecture
High match
Package and Pinout
High match
INL and DNL Grade
Validation required
Supply and Interface
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 | AD977ABRS | AD977BRS | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 16 bit | Both converters provide 16-bit resolution, so quantization noise floor and dynamic range are equivalent. |
| Sampling Rate | 100 kSPS | 100 kSPS | Identical maximum throughput means either part can meet the same acquisition timing requirements. |
| INL (Integral Nonlinearity) | ±2.0 LSB max | ±3.0 LSB max | The A-grade offers tighter linearity, which directly affects absolute accuracy and distortion in precision measurement applications. |
| DNL (Differential Nonlinearity) | ±1 LSB max | ±1 LSB max | Guaranteed no missing codes for both grades, so monotonicity performance is equivalent. |
| Input Voltage Range | ±10 V (bipolar) | ±10 V (bipolar) | Same analog input span allows direct substitution without front-end signal conditioning changes. |
| Supply Voltage | 5 V (single supply) | 5 V (single supply) | Identical supply requirements mean the same power rail design can be reused. |
| Interface | Parallel (byte/word) | Parallel (byte/word) | Same digital interface protocol ensures drop-in compatibility with the host processor bus. |
| Package | 28-lead SSOP | 28-lead SSOP | Identical footprint and pinout permit physical board substitution without layout changes. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Same industrial temperature rating means both parts suit the same environmental conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD977ABRS | AD977BRS |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Obsolete | Obsolete |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 200k | 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 AD977ABRS and AD977BRS?
Both are 16-bit, 100 kSPS analog-to-digital converters from Analog Devices in a 28-lead SSOP (RS) package. The primary difference is the grade: the AD977ABRS is specified for a maximum integral nonlinearity (INL) of ±2 LSB, while the AD977BRS is specified for a maximum INL of ±3 LSB. Both share the same pinout, package, and core architecture.
Are the AD977ABRS and AD977BRS pin-compatible and package-compatible?
Yes. Both devices are offered in the same 28-lead SSOP (RS) package with identical pin functions, so they are pin-compatible and share the same PCB land pattern.
Do the AD977ABRS and AD977BRS have the same resolution and throughput?
Yes. Both are 16-bit successive-approximation ADCs with a maximum throughput of 100 kSPS, and both support the same serial and parallel output interface options.
Can the AD977ABRS be used as a drop-in replacement for the AD977BRS?
Because they are pin-compatible and functionally identical, the AD977ABRS can generally serve as a higher-grade replacement for the AD977BRS, provided the tighter ±2 LSB INL specification and the associated operating conditions are acceptable for the target design. The reverse substitution (using the B grade where the A grade is specified) should only be made after verifying that the looser ±3 LSB INL meets the system accuracy requirements.
What is the difference in accuracy specification between the two grades?
The AD977ABRS is specified with a maximum INL of ±2 LSB, while the AD977BRS is specified with a maximum INL of ±3 LSB. This is the principal parametric distinction between the two grades; other core specifications such as resolution and sample rate are the same.
Do both parts support the same analog input range and reference configuration?
Yes. Both the AD977ABRS and AD977BRS use the same analog input structure and reference configuration, supporting the same input range options and external reference arrangements as defined in the AD977 datasheet.
Are the AD977ABRS and AD977BRS available in the same operating temperature range?
Both the AD977ABRS and AD977BRS are specified over the industrial temperature range of −40°C to +85°C, consistent with the RS package grade designation in the AD977 datasheet.