Part A
AD977ABRS
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 1992 PCS
- Package
- SSOP-28
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD977AARSZ and AD977ABRS are functionally equivalent 16-bit successive-approximation ADCs sharing the same resolution, analog input architecture, and 100 kSPS throughput, making them strong drop-in candidates for most designs. The primary distinction lies in package and temperature-grade qualification, so designers should confirm the SSOP-28 footprint and operating temperature range against their specific application requirements before final substitution.
Resolution
High match
Sampling Rate
High match
Package Type
High match
Operating Temperature Range
Validation required
Parts at a glance
Part B
AD977AARSZ
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 5427 PCS
- Package
- SSOP-28
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD977AARSZ | AD977ABRS | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 16 bit | Both are 16-bit ADCs, so conversion resolution is identical and not a differentiator for substitutability. |
| Sampling Rate | 200 kSPS | 100 kSPS | The A-grade supports 200 kSPS while the B-grade is limited to 100 kSPS; this affects maximum throughput and timing budget in the application. |
| INL (Integral Nonlinearity) | ±2 LSB max | ±3 LSB max | The A-grade offers tighter linearity, which directly impacts accuracy and measurement error in precision acquisition systems. |
| DNL (Differential Nonlinearity) | ±1 LSB max | ±1 LSB max | Both grades guarantee no missing codes with ±1 LSB DNL, so monotonicity performance is equivalent. |
| Input Type | Single-ended | Single-ended | Both accept single-ended analog inputs, so the analog front-end topology can remain unchanged when substituting. |
| Supply Voltage | 5 V (analog and digital) | 5 V (analog and digital) | Identical 5 V supply requirements mean the power design does not need modification between the two parts. |
| Interface | Parallel (byte/word) | Parallel (byte/word) | Both provide a parallel microprocessor interface, so the digital host connection is compatible across grades. |
| Package / Mounting | 28-SSOP (RS-28) | 28-SSOP (RS-28) | Same SSOP package and footprint allow drop-in board replacement without layout changes. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical industrial temperature ratings ensure the same environmental qualification applies to both grades. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD977ABRS | AD977AARSZ |
|---|---|---|
| Part Status | Obsolete | Active |
| 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 AD977AARSZ and the AD977ABRS?
Both devices are 16-bit, 100 kSPS analog-to-digital converters from Analog Devices. The AD977AARSZ is the RoHS-compliant version in a 28-lead SSOP package, while the AD977ABRS is the non-RoHS version of the same converter in the same 28-lead SSOP package. The core converter specifications (resolution, throughput, input range, and interface) are equivalent; the primary difference is the RoHS compliance status and the corresponding ordering part number.
Are the AD977AARSZ and AD977ABRS pin-compatible?
Yes. Both parts are offered in the same 28-lead SSOP (RS) package and share the same pinout, so they are pin-compatible when the PCB assembly process permits the applicable RoHS or non-RoHS finish.
What is the resolution and throughput of these converters?
Both the AD977AARSZ and AD977ABRS are 16-bit successive-approximation ADCs with a maximum throughput of 100 kSPS.
What analog input range do the AD977AARSZ and AD977ABRS support?
Both devices accept a bipolar input range of ±10 V, with the input configuration set by the external reference and input scaling components as described in the AD977 datasheet.
What digital interface do these ADCs provide?
Both parts provide a parallel digital output interface for reading conversion results, along with the control signals (such as conversion start and busy/status) defined in the AD977 datasheet.
Can the AD977AARSZ be used as a drop-in replacement for the AD977ABRS?
Functionally and pin-wise, yes, because both are the same converter in the same 28-lead SSOP package. The substitution should be validated against the assembly's RoHS requirements and the manufacturer's ordering documentation, since the AD977AARSZ is the RoHS-compliant variant and the AD977ABRS is not.
What supply voltage do the AD977AARSZ and AD977ABRS require?
Both devices operate from a +5 V analog supply and a +5 V digital supply, as specified in the AD977 datasheet. Refer to the manufacturer datasheet for the exact supply tolerances and decoupling requirements.