Part A
AD7894ARZ-3
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3263 ПКС
- Package
- SOIC-8
- Series
- Сбор данных - аналогово-цифровые преобразователи (ADC)
Replacement verdict
Not a drop-in replacement
The AD7894ARZ-3 and AD7892BR-2 are not drop-in replacements for one another. Although both are Analog Devices 12-bit successive-approximation ADCs, they differ in resolution-related speed grade, analog input configuration, package and pinout, and external component requirements, so a direct board-level substitution is not possible without redesign.
Different conversion speed grade
Different analog input configuration
Different package and pinout
Different external component requirements
Parts at a glance
Part B
AD7892BR-2
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 9420 ПКС
- Package
- SOIC-24
- 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 | AD7894ARZ-3 | AD7892BR-2 | Why it matters |
|---|---|---|---|
| Resolution | 14 bit | 12 bit | Higher resolution provides finer quantization steps, which directly affects measurement accuracy and dynamic range in the application. |
| Number of ADC Inputs | 1 (single-ended) | 2 (single-ended) | The number of input channels determines how many analog signals can be digitized without external multiplexing. |
| Sampling Rate | 200 kSPS | 500 kSPS | Maximum throughput limits the bandwidth of signals that can be captured and impacts anti-aliasing requirements. |
| Input Voltage Range | ±2.5 V (bipolar) | 0 V to +2.5 V (unipolar) | The input span must match the sensor or signal source; bipolar vs unipolar affects signal conditioning and offset handling. |
| Supply Voltage | 5 V single supply | 5 V single supply | Supply compatibility ensures the part can drop into the same power rail without additional regulation. |
| Interface Type | Serial (SPI/QSPI compatible) | Parallel | The digital interface must match the host controller; serial vs parallel changes pin count, board routing, and firmware. |
| Package / Mounting | 20-lead SOIC (surface mount) | 24-lead SOIC (surface mount) | Package footprint and pin count affect PCB layout compatibility and whether a direct board swap is possible. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | The temperature range must cover the application environment to guarantee specified performance. |
| Power Consumption | Typically ~20 mW at 5 V | Typically ~60 mW at 5 V | Power dissipation affects thermal budget and is critical in portable or thermally constrained designs. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7894ARZ-3 | AD7892BR-2 |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | 14 | 12 |
| Sampling Rate(Per Second) | 200k | 500k |
| Number of A/D Converters | 1 | 1 |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Number of Inputs | 1 | - |
| Input Type | Single Ended | - |
| Data Interface | SPI | - |
| Configuration | S/H-ADC | - |
| Ratio - S / H: ADC | 1:1 | - |
| Architecture | SAR | - |
| Reference Type | External | - |
| Voltage - Supply, Analog | 5V | - |
| Voltage - Supply, Digital | 5V | - |
Frequently asked questions
What are the key differences between the AD7894ARZ-3 and the AD7892BR-2?
The AD7894ARZ-3 is a 14-bit successive-approximation ADC with a 5 V single-supply operation and a 0 V to +2.5 V input range, housed in a 24-lead SOIC package. The AD7892BR-2 is a 12-bit ADC with a 5 V supply and a ±2.5 V bipolar input range, also in a 24-lead SOIC package. The AD7894 offers higher resolution (14-bit vs 12-bit), while the AD7892BR-2 provides a bipolar input range and a faster throughput rate (500 kSPS vs 200 kSPS for the AD7894).
Are the AD7894ARZ-3 and AD7892BR-2 pin-compatible?
No. Although both devices are offered in a 24-lead SOIC package, their pinouts differ. The AD7894ARZ-3 and AD7892BR-2 have different pin functions and assignments, so they are not drop-in replacements for each other. PCB layout and pin connections must be reviewed against the respective datasheets before considering any substitution.
What are the resolution and throughput specifications of each device?
The AD7894ARZ-3 provides 14-bit resolution with a maximum throughput of 200 kSPS. The AD7892BR-2 provides 12-bit resolution with a maximum throughput of 500 kSPS. The AD7892BR-2 therefore offers a higher sampling rate, while the AD7894ARZ-3 offers finer quantization resolution.
What input voltage ranges do these ADCs support?
The AD7894ARZ-3 has a unipolar input range of 0 V to +2.5 V. The AD7892BR-2 has a bipolar input range of ±2.5 V. The choice between them depends on whether the signal to be digitized is unipolar or bipolar.
Do both devices operate from a single 5 V supply?
Yes. Both the AD7894ARZ-3 and the AD7892BR-2 operate from a single +5 V supply. This makes them suitable for systems with a 5 V analog rail, though the input range and resolution differences remain the primary selection criteria.
What package type do the AD7894ARZ-3 and AD7892BR-2 use?
Both devices are supplied in a 24-lead SOIC package. The "RZ" suffix in AD7894ARZ-3 and the "BR" suffix in AD7892BR-2 both denote the SOIC package option. Despite the common package style, the internal pin assignments differ between the two parts.
Can the AD7894ARZ-3 be used as a direct replacement for the AD7892BR-2 in an existing design?
No. A direct replacement is not possible without design changes. The two devices differ in resolution (14-bit vs 12-bit), input range (0 V to +2.5 V vs ±2.5 V), throughput (200 kSPS vs 500 kSPS), and pinout. Any substitution requires verification against the manufacturer datasheets and validation of the target design's signal chain, timing, and PCB layout.