Part A
AD7891ASZ-1
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5058 ПКС
- Package
- SOIC-8
- Series
- Сбор данных - ADC-DAC - Специальное назначение
Replacement verdict
Not a drop-in replacement
The AD7891ASZ-1 and AD7893BR-2 are not drop-in replacements for one another. The AD7891ASZ-1 is an 8-channel, 12-bit data acquisition system with a parallel interface, while the AD7893BR-2 is a single-channel, 12-bit ADC with a serial interface. Their channel count, output interface, package footprint, and throughput characteristics differ substantially, so substituting one for the other requires a full board and firmware redesign rather than a direct swap.
Different channel count
Different output interface
Different package footprint
Different throughput class
Parts at a glance
Part B
AD7893BR-2
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5300 ПКС
- Package
- SOIC-8
- Series
- Сбор данных - аналогово-цифровые преобразователи (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 | AD7891ASZ-1 | AD7893BR-2 | Why it matters |
|---|---|---|---|
| Number of ADC Channels | 8 (single-ended) | 1 (single-ended) | Determines how many analog signals can be digitized; the AD7891 handles multi-channel systems while the AD7893 is single-channel only. |
| Resolution | 12 bits | 12 bits | Both provide 12-bit resolution, so quantization accuracy is equivalent and neither offers a resolution advantage. |
| Sampling Rate | 500 kSPS | 117 kSPS | Higher throughput allows faster signal capture; the AD7891 supports much faster sampling than the AD7893. |
| Input Type | Single-ended | Single-ended | Both accept single-ended inputs, so signal conditioning topology is compatible between the two parts. |
| Interface | Parallel | Serial (SPI/QSPI/MICROWIRE compatible) | The digital interface dictates microcontroller pin count and firmware; parallel vs serial makes them non-drop-in replacements. |
| Supply Voltage | 5 V | 5 V | Both operate from a single 5 V supply, so power rail requirements are identical. |
| Package | 44-lead MQFP | 8-lead SOIC | Footprint and board space differ significantly; the AD7893 is far smaller and not layout-compatible with the AD7891. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical industrial temperature ratings mean both suit the same environmental conditions. |
| Input Voltage Range | ±10 V (bipolar) | 0 V to +2.5 V (unipolar) | Input span affects signal scaling and front-end design; the AD7891 accepts bipolar signals while the AD7893 is unipolar. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7891ASZ-1 | AD7893BR-2 |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | - | 12 |
| Sampling Rate(Per Second) | 500k | 117k |
| Number of Inputs | - | 1 |
| Input Type | - | Single Ended |
| Data Interface | Serial, Parallel | SPI |
| Configuration | - | S/H-ADC |
| Ratio - S / H: ADC | - | 1:1 |
| Number of A/D Converters | - | 1 |
| Architecture | - | SAR |
| Reference Type | - | External |
| Voltage - Supply, Analog | - | 5V |
| Voltage - Supply, Digital | - | 5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Type | Data Acquisition System (DAS) | - |
| Number of Channels | 8 | - |
| Resolution(Bits) | 12 b | - |
| Voltage Supply Source | Single Supply | - |
| Voltage - Supply | 5V | - |
| Mounting Type | Surface Mount | - |
Frequently asked questions
What are the primary differences between the AD7891ASZ-1 and AD7893BR-2?
The AD7891ASZ-1 is an 8-channel, 12-bit data acquisition system with a 1.6 µs conversion time and a parallel interface, housed in a 44-lead MQFP. The AD7893BR-2 is a single-channel, 12-bit successive-approximation ADC with a 6 µs conversion time and a serial interface, housed in an 8-lead SOIC. The AD7891ASZ-1 integrates an input multiplexer and track-and-hold, while the AD7893BR-2 requires an external reference and provides a single input channel.
Can the AD7891ASZ-1 and AD7893BR-2 be used interchangeably in an existing design?
No. The two devices differ in package footprint (44-lead MQFP vs 8-lead SOIC), interface type (parallel vs serial), channel count (8 vs 1), and reference architecture. They are not pin-compatible or functionally interchangeable without a complete redesign of the PCB and digital interface.
What are the resolution and conversion time specifications for each device?
Both devices offer 12-bit resolution. The AD7891ASZ-1 has a conversion time of 1.6 µs typical, while the AD7893BR-2 has a conversion time of 6 µs typical. These figures are specified in the respective manufacturer datasheets.
How do the input configurations of the AD7891ASZ-1 and AD7893BR-2 differ?
The AD7891ASZ-1 provides eight single-ended input channels via an on-chip multiplexer with a track-and-hold amplifier. The AD7893BR-2 provides a single analog input channel and requires an external track-and-hold or sample-and-hold circuit if simultaneous sampling is needed. The AD7891ASZ-1 also supports software-selectable input ranges, whereas the AD7893BR-2 has a fixed input range determined by the external reference.
What digital interfaces do the AD7891ASZ-1 and AD7893BR-2 use?
The AD7891ASZ-1 uses a parallel microprocessor interface with 12 data lines and control signals for read and convert start. The AD7893BR-2 uses a serial interface compatible with SPI, QSPI, and MICROWIRE protocols, requiring fewer PCB traces and suited to isolated or space-constrained designs.
Do the AD7891ASZ-1 and AD7893BR-2 require external references?
The AD7891ASZ-1 includes an on-chip reference and can also operate with an external reference. The AD7893BR-2 requires an external reference voltage to be supplied by the user; it does not contain an internal reference. This difference affects system accuracy budgeting and board-level component count.
What are the package and operating temperature specifications for each device?
The AD7891ASZ-1 is supplied in a 44-lead MQFP package and is specified for operation over the industrial temperature range of −40°C to +85°C. The AD7893BR-2 is supplied in an 8-lead SOIC package and is specified for operation over the industrial temperature range of −40°C to +85°C. Package and temperature grade should be confirmed against the latest manufacturer datasheet revision.