Part A
AD7890ARZ-10
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6285 PCS
- Package
- SOIC-24
- Series
- Acquisição de dados - ADCs-DACs - Objetivo Especial
Replacement verdict
Compatible functional replacement candidate
The AD7890ARZ-10 and AD7890AR-2 are functionally compatible 12-bit, 8-channel data acquisition systems in the same 24-lead SOIC package, sharing the same serial interface, on-chip track-and-hold, and reference architecture. The primary distinction is the specified input voltage range, which must be validated against the target application's signal chain before substitution.
Package Type
High match
Resolution
High match
Input Voltage Range
Validation required
Serial Interface
High match
Parts at a glance
Part B
AD7890AR-2
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7872 PCS
- Package
- SOIC-24
- Series
- Acquisição de dados - ADCs-DACs - Objetivo Especial
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD7890ARZ-10 | AD7890AR-2 | Why it matters |
|---|---|---|---|
| Number of Input Channels | 8 (single-ended) | 8 (single-ended) | Channel count determines how many analog signals the system can monitor; both parts match here. |
| Resolution | 12 bits | 12 bits | Resolution sets the smallest detectable signal change; identical 12-bit resolution supports equivalent measurement precision. |
| Input Voltage Range | ±10 V | ±2.5 V | The full-scale input range must match the sensor or signal amplitude; a ±10 V part cannot directly replace a ±2.5 V part without signal conditioning. |
| Sampling Rate | 117 kSPS | 117 kSPS | Throughput determines the maximum signal bandwidth that can be captured; both devices offer the same conversion rate. |
| Supply Voltage | 5 V (single supply) | 5 V (single supply) | Supply compatibility ensures the part can drop into the same power rail; both operate from a single 5 V supply. |
| Interface Type | Serial (SPI-compatible) | Serial (SPI-compatible) | The digital interface must match the host controller; both use a serial interface, simplifying substitution. |
| Package / Mounting | 24-lead SOIC (surface mount) | 24-lead SOIC (surface mount) | Package and footprint must be compatible for board-level replacement; both share the same SOIC outline. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Temperature range affects reliability in the target environment; both cover the industrial range. |
| Reference Type | Internal reference | Internal reference | An internal reference simplifies design and reduces external components; both integrate the reference. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7890ARZ-10 | AD7890AR-2 |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Type | Data Acquisition System (DAS) | Data Acquisition System (DAS) |
| Number of Channels | 8 | 8 |
| Resolution(Bits) | 12 b | 12 b |
| Sampling Rate(Per Second) | 117k | 117k |
| Data Interface | SPI | SPI |
| Voltage Supply Source | Single Supply | Single Supply |
| Voltage - Supply | 5V | 5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the key differences between the AD7890ARZ-10 and the AD7890AR-2?
Both are 12-bit, 8-channel successive-approximation ADCs from Analog Devices in a 24-lead SOIC package, but they differ in specified input voltage range and speed grade. The AD7890ARZ-10 is specified for a ±10 V input range, while the AD7890AR-2 is specified for a ±2.5 V input range. The "Z" suffix on the AD7890ARZ-10 denotes RoHS-compliant lead-free construction, whereas the AD7890AR-2 is the non-RoHS version.
Are the AD7890ARZ-10 and AD7890AR-2 pin-compatible?
Yes. Both devices are offered in the same 24-lead SOIC (R-24) package with identical pin functions, so they are pin-compatible. The functional difference is the analog input range, not the pinout.
Can the AD7890ARZ-10 be used as a drop-in replacement for the AD7890AR-2?
Not without design review. Although the package and pinout match, the AD7890ARZ-10 accepts ±10 V inputs while the AD7890AR-2 accepts ±2.5 V inputs. Substituting one for the other changes the full-scale input range and therefore the LSB size and the voltage seen by the ADC, so the analog front end and system scaling must be validated against the Analog Devices datasheet before substitution.
What is the resolution and architecture of these AD7890 devices?
Both the AD7890ARZ-10 and AD7890AR-2 are 12-bit successive-approximation register (SAR) ADCs with an 8-channel input multiplexer, a track-and-hold amplifier, and an on-chip reference, per the Analog Devices AD7890 datasheet.
How does the input voltage range affect the LSB size for each part?
For a 12-bit converter, one LSB equals the full-scale span divided by 4096. The AD7890ARZ-10 with a ±10 V range has a 20 V span, giving an LSB of approximately 4.88 mV. The AD7890AR-2 with a ±2.5 V range has a 5 V span, giving an LSB of approximately 1.22 mV.
Do the AD7890ARZ-10 and AD7890AR-2 differ in RoHS compliance?
Yes. The "Z" in AD7890ARZ-10 indicates a RoHS-compliant, lead-free package per Analog Devices ordering conventions. The AD7890AR-2 does not carry the Z suffix and is the non-RoHS version. Designs requiring RoHS compliance should use the AD7890ARZ-10.
What digital interface do these ADCs provide?
Both parts provide a high-speed serial interface for connection to microprocessors and DSPs, along with a conversion-start input and a busy/status output, as described in the Analog Devices AD7890 datasheet. The interface is common to both the AD7890ARZ-10 and AD7890AR-2.