Part A
AD977ABRS
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 1992 ПКС
- Package
- SSOP-28
- Series
- Сбор данных - аналогово-цифровые преобразователи (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD977ABRS and AD977AARS are functionally equivalent 16-bit 100 kSPS ADCs sharing the same resolution, sample rate, and 28-lead SSOP package, differing only in specified grade and temperature range. The AD977AARS offers a higher-grade specification over the industrial temperature range, making it a viable functional replacement candidate for the AD977ABRS where the tighter grade and extended temperature performance are acceptable or beneficial.
Resolution
High match
Sample Rate
High match
Package Type
High match
Grade and 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 | AD977ABRS | AD977AARS | Why it matters |
|---|---|---|---|
| Package / Case | 28-SSOP (Shrink Small Outline Package) | 28-SSOP (Shrink Small Outline Package) | Package type determines PCB footprint and assembly compatibility; both share the same SSOP body, so footprint is interchangeable. |
| Resolution | 16 bits | 16 bits | Bit resolution defines the ADC's quantization granularity; identical resolution means equivalent measurement precision. |
| Sampling Rate | 100 kSPS | 100 kSPS | Maximum throughput determines the highest signal bandwidth the converter can digitize; matching rates preserve system timing behavior. |
| Input Type | Single-ended | Single-ended | Input configuration affects analog front-end design; both being single-ended means the same signal conditioning circuitry applies. |
| Supply Voltage | 5 V (analog and digital) | 5 V (analog and digital) | Operating supply voltage must match the board's power rails; identical 5 V requirement allows direct substitution without rail changes. |
| Interface | Serial (SPI-compatible) | Serial (SPI-compatible) | Digital interface protocol determines host controller compatibility; matching serial interface enables drop-in replacement. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Temperature range defines environmental robustness; identical industrial range means equivalent application suitability. |
| Reference Type | Internal | Internal | On-chip reference simplifies design and reduces external components; both having internal references ensures equivalent system architecture. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD977ABRS | AD977AARS |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Obsolete | Obsolete |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 200k | 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 AD977ABRS and AD977AARS?
Both are 16-bit, 100 kSPS analog-to-digital converters from Analog Devices in a 28-lead SSOP package. The primary difference is the grade: the AD977ABRS is a B-grade device with specified INL of ±2 LSB max and DNL of ±1 LSB max, while the AD977AARS is an A-grade device with specified INL of ±3 LSB max and DNL of ±2 LSB max. Both grades are specified over the industrial temperature range of −40°C to +85°C.
Are the AD977ABRS and AD977AARS pin-compatible and package-compatible?
Yes. Both devices are offered in the same 28-lead SSOP (RS suffix) package with identical pin functions, so they are pin-to-pin and footprint compatible. The difference between the two part numbers is the performance grade, not the package or pinout.
Can the AD977AARS be used as a drop-in replacement for the AD977ABRS?
Physically yes, since both share the same 28-lead SSOP footprint and pinout. However, the AD977AARS has looser linearity specifications (INL ±3 LSB max, DNL ±2 LSB max) than the AD977ABRS (INL ±2 LSB max, DNL ±1 LSB max). A design that requires B-grade linearity should not substitute the A-grade part without validating that the relaxed INL/DNL limits still meet the system accuracy budget.
What are the resolution and throughput specifications of these converters?
Both the AD977ABRS and AD977AARS are 16-bit successive-approximation ADCs with a maximum throughput of 100 kSPS. They operate from a single +5 V supply and include an internal 2.5 V reference, a sample-and-hold amplifier, and a serial interface for data output.
Do the AD977ABRS and AD977AARS differ in power consumption or supply requirements?
No. Both grades share the same supply and power specifications: a single +5 V analog supply with a separate +5 V digital supply (VDRIVE) for the interface, and typical power dissipation of 100 mW. Power consumption is not a differentiating factor between the A and B grades.
What interface do the AD977ABRS and AD977AARS provide?
Both devices provide a serial data output interface compatible with SPI/QSPI/MICROWIRE and DSP serial ports. The conversion result is available as a 16-bit serial word, and the devices also support a read-only mode for interfacing to microcontrollers and DSPs.
Which grade should be selected for a design requiring tight integral nonlinearity?
For designs requiring tighter INL, the AD977ABRS should be selected because its maximum INL is ±2 LSB versus ±3 LSB for the AD977AARS. The B grade offers better guaranteed linearity performance and is the appropriate choice when the error budget cannot tolerate the A-grade limits.
Are the AD977ABRS and AD977AARS specified over the same temperature range?
Yes. Both the AD977ABRS and AD977AARS are specified over the industrial temperature range of −40°C to +85°C, so temperature range is not a selection criterion between the two grades.