Part A
AD7891ASZ-1
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 5058 PCS
- Package
- SOIC-8
- Series
- Acquisition de données - ADC DAC - dédié
Replacement verdict
Not a drop-in replacement
The AD7891ASZ-1 and AD7892BR-2 are not drop-in replacements for one another. The AD7891ASZ-1 is an 8-channel multiplexed 12-bit ADC, while the AD7892BR-2 is a single-channel 12-bit ADC with a different analog input architecture and package. Designers must account for differences in channel count, input configuration, package footprint, and interface timing before considering any substitution.
Different channel count
Different input configuration
Different package footprint
Different interface timing
Parts at a glance
Part B
AD7892BR-2
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 9420 PCS
- Package
- SOIC-24
- 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 | AD7891ASZ-1 | AD7892BR-2 | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both are 12-bit ADCs, so nominal quantization resolution is equivalent for substitutability. |
| Number of ADC Inputs / Channels | 8 single-ended (multiplexed) | 1 single-ended | The AD7891 provides an 8-channel multiplexer while the AD7892 is single-channel, which fundamentally changes system architecture and channel count. |
| Sampling Rate | 500 kSPS | 500 kSPS | Identical maximum throughput means timing and throughput budgets remain compatible. |
| Input Voltage Range | ±10 V (bipolar) | ±10 V (bipolar) | Matching input range allows the same signal conditioning front-end to be reused. |
| Interface Type | Parallel | Serial (SPI/QSPI compatible) | Parallel versus serial interface affects microcontroller pin count, board routing, and firmware, so they are not drop-in interchangeable. |
| Supply Voltage | 5 V | 5 V | Same single 5 V supply simplifies power rail design and compatibility. |
| Package | 44-Lead MQFP | 24-Lead SOIC | Different package footprints and pin counts prevent direct PCB substitution without layout changes. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical industrial temperature range supports use in the same environmental conditions. |
| Integral Nonlinearity (INL) | ±1 LSB | ±1 LSB | Equivalent linearity specification indicates comparable accuracy performance. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7891ASZ-1 | AD7892BR-2 |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | - | 12 |
| Sampling Rate(Per Second) | 500k | 500k |
| Number of A/D Converters | - | 1 |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Type | Data Acquisition System (DAS) | - |
| Number of Channels | 8 | - |
| Resolution(Bits) | 12 b | - |
| Data Interface | Serial, Parallel | - |
| 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 AD7892BR-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 AD7892BR-2 is a single-channel, 12-bit ADC with a 1.47 µs conversion time and a serial interface, housed in a 24-lead SOIC. The AD7891ASZ-1 integrates an 8-channel multiplexer, while the AD7892BR-2 is a single-channel device.
Are the AD7891ASZ-1 and AD7892BR-2 pin-compatible?
No. The AD7891ASZ-1 uses a 44-lead MQFP package, while the AD7892BR-2 uses a 24-lead SOIC package. The pin counts, pin functions, and package footprints differ, so they are not pin-compatible or directly interchangeable on the same PCB land pattern.
What are the input voltage ranges for each device?
The AD7891ASZ-1 offers selectable input ranges of ±10 V, ±5 V, and 0 V to 5 V (depending on the model suffix; the ASZ-1 variant supports ±10 V and ±5 V). The AD7892BR-2 offers a ±10 V input range (the BR-2 grade specifies a ±10 V bipolar input range). Designers should confirm the exact range option from the respective datasheet before use.
How do the interface types differ between the AD7891ASZ-1 and AD7892BR-2?
The AD7891ASZ-1 provides a parallel microprocessor interface for direct connection to a host bus. The AD7892BR-2 provides a serial interface for connection to serial ports or DSP/microcontroller serial peripherals. This difference affects system architecture, pin count, and firmware design.
Do both parts operate from the same supply voltage?
Both devices operate from a single +5 V analog supply. The AD7891ASZ-1 also requires a +5 V digital supply for its parallel interface, while the AD7892BR-2 operates from a single +5 V supply for both analog and digital functions. Always verify the exact supply requirements in the manufacturer datasheet for the specific grade.
Can the AD7892BR-2 replace the AD7891ASZ-1 in an existing design?
Not directly. The AD7891ASZ-1 provides 8 multiplexed input channels and a parallel interface, whereas the AD7892BR-2 is a single-channel device with a serial interface. A replacement would require redesign of the input multiplexing, interface, and PCB layout, and is not a drop-in substitution.
What are the conversion times and throughput of these ADCs?
The AD7891ASZ-1 has a conversion time of 1.6 µs and supports throughput up to 500 kSPS. The AD7892BR-2 has a conversion time of 1.47 µs and supports throughput up to 600 kSPS. These figures are specified in the respective manufacturer datasheets and should be confirmed for the exact grade and operating conditions.