Part A
AD7891ASZ-2
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 1328 PCS
- Package
- QFP-44
- Series
- Acquisition de données - ADC DAC - dédié
Replacement verdict
Compatible functional replacement candidate
The AD7891ASZ-2 and AD7891YS-2 are functionally compatible 12-bit data acquisition systems sharing the same package, pinout, and core architecture, with the Y-grade offering a higher performance grade over the A-grade. The primary distinction lies in the specified performance grade and operating temperature range, so the Y-grade can serve as a functional substitute for the A-grade where the extended temperature range and tighter specifications are acceptable, while the reverse substitution requires validation against the application's accuracy and temperature requirements.
Package Type
High match
Resolution
High match
Performance Grade
Validation required
Operating Temperature Range
Validation required
Parts at a glance
Part B
AD7891YS-2
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 3710 PCS
- Package
- QFP-44
- Series
- Acquisition de données - ADC DAC - dédié
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD7891ASZ-2 | AD7891YS-2 | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both parts share the same 12-bit resolution, so conversion accuracy and code width are equivalent for direct substitution. |
| Number of Input Channels | 8 single-ended | 8 single-ended | Identical channel count means the same signal routing and multiplexer configuration can be reused. |
| Sampling Rate | 500 kSPS | 500 kSPS | Matching throughput ensures the same timing budget and anti-aliasing requirements apply. |
| Input Voltage Range | ±10 V (bipolar) | ±10 V (bipolar) | Same full-scale input range allows the analog front-end and signal conditioning to remain unchanged. |
| Supply Voltage | 5 V | 5 V | Identical supply requirement means the same power rail and decoupling network can be used. |
| Interface Type | Parallel | Parallel | Same parallel interface keeps the digital bus and microcontroller connection compatible. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +105 °C | The YS grade supports a wider temperature range, which matters for industrial or harsh-environment applications. |
| Package / Mounting | 44-Lead MQFP (surface mount) | 44-Lead MQFP (surface mount) | Same package and footprint allow drop-in board replacement without layout changes. |
| Grade / Accuracy Class | A grade | Y grade | Different grade designations indicate differing guaranteed specifications such as linearity and offset, affecting precision-critical 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 | AD7891ASZ-2 | AD7891YS-2 |
|---|---|---|
| Supplier | - | 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) | 500k | 500k |
| Data Interface | Serial, Parallel | Serial, Parallel |
| Voltage Supply Source | Single Supply | Single Supply |
| Voltage - Supply | 5V | 5V |
| Operating Temperature | -40°C ~ 85°C | -55°C ~ 105°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the key differences between the AD7891ASZ-2 and AD7891YS-2?
Both are 8-channel, 12-bit successive-approximation ADCs from Analog Devices in the same 44-lead MQFP package and share the same functional architecture. The primary difference is the grade: the AD7891ASZ-2 is specified for the commercial/industrial temperature range, while the AD7891YS-2 is specified for the extended industrial temperature range. The "Y" grade is tested and guaranteed over a wider temperature span than the "A" grade, which affects accuracy specifications at temperature extremes.
Are the AD7891ASZ-2 and AD7891YS-2 pin-compatible and package-compatible?
Yes. Both devices are offered in the same 44-lead MQFP (MQFP-44) package with identical pin assignments, so they are pin-for-pin and footprint-compatible. PCB land patterns and mechanical dimensions are the same for both grades.
What is the resolution and throughput of these AD7891 devices?
Both the AD7891ASZ-2 and AD7891YS-2 are 12-bit ADCs with a maximum throughput of 500 kSPS. They provide eight single-ended input channels (or four differential channels) via an on-chip input multiplexer, with a conversion time of approximately 1.6 µs.
What analog input ranges do the AD7891ASZ-2 and AD7891YS-2 support?
Both devices support selectable input ranges of ±10 V, ±5 V, and 0 V to +2.5 V (with the appropriate reference and configuration). The input range is software-selectable through the device's control register, allowing the same part to interface with different signal levels.
What supply voltage and interface do these parts require?
Both devices operate from a single +5 V analog supply and a separate +5 V digital supply (VDD). They include a parallel microprocessor interface with a high-speed 12-bit parallel output, and they also provide a serial interface option. The devices feature an on-chip track-and-hold and reference circuitry.
Can the AD7891YS-2 be used as a drop-in replacement for the AD7891ASZ-2?
Functionally and pin-wise, yes, since both share the same package, pinout, and architecture. However, the AD7891YS-2 is the higher-grade device specified over a wider temperature range, so it can generally replace the AD7891ASZ-2 in applications requiring extended temperature operation. The reverse substitution (using the A-grade in place of the Y-grade) is only acceptable if the application's temperature range and accuracy requirements are met by the A-grade specifications.
What are the operating temperature ranges for the AD7891ASZ-2 and AD7891YS-2?
The AD7891ASZ-2 is specified over the commercial/industrial temperature range (0°C to +70°C for the A grade per the datasheet ordering guide), while the AD7891YS-2 is specified over the extended industrial range of −40°C to +85°C. Designers should confirm the exact grade suffix against the Analog Devices datasheet ordering information for the target application.
Do both parts offer the same accuracy and linearity specifications?
Both are 12-bit devices with guaranteed no-missing-codes performance and typical integral nonlinearity (INL) and differential nonlinearity (DNL) within ±1 LSB. Because the Y grade is tested over a wider temperature range, its guaranteed accuracy limits at temperature extremes are tighter than those of the A grade. For precision at extended temperatures, the AD7891YS-2 is the appropriate choice.