Part A
AD7894ARZ-3
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 3263 個数
- Package
- SOIC-8
- Series
- データ取得 - アナログ/デジタルコンバータ (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7898AR-3 can serve as a functional replacement candidate for the AD7894ARZ-3 in many 12-bit ADC applications, as both share a comparable resolution, serial interface, and small SOIC footprint. However, designers must validate the differing throughput rate, analog input range, and supply voltage requirements against the target system before committing to a drop-in substitution.
Resolution
Validation required
Sample Rate
Validation required
Analog Input Range
Validation required
Package Type
High match
Parts at a glance
Part B
AD7898AR-3
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 7616 個数
- Package
- SOIC-8
- Series
- データ取得 - アナログ/デジタルコンバータ (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 | AD7898AR-3 | Why it matters |
|---|---|---|---|
| Resolution | 14 bit | 12 bit | Resolution determines the smallest analog change the ADC can distinguish; a 14-bit part offers finer quantization than a 12-bit part, affecting measurement precision. |
| Number of Input Channels | 1 (single-ended) | 1 (single-ended) | Channel count defines how many analog signals can be digitized; both are single-channel, so multiplexing needs are equivalent. |
| Sampling Rate | 200 kSPS | 200 kSPS | Throughput sets the maximum signal bandwidth that can be captured; matching rates mean similar timing performance in the system. |
| Input Voltage Range | ±2.5 V (bipolar) | 0 V to 2.5 V (unipolar) | Input range must match the sensor or signal swing; a bipolar range suits AC or signed signals, while a unipolar range suits single-supply positive signals. |
| Supply Voltage | 5 V | 5 V | Supply voltage must be compatible with the host system rails; identical 5 V operation simplifies power design and substitution. |
| Interface Type | Serial (SPI/QSPI compatible) | Serial (SPI/QSPI compatible) | The digital interface determines how the ADC connects to a microcontroller or DSP; matching serial interfaces allow drop-in digital compatibility. |
| Package / Mounting | 20-lead SOIC (surface mount) | 8-lead SOIC (surface mount) | Package footprint and pin count affect PCB layout; different packages require board redesign even if electrical specs match. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Temperature range indicates environmental robustness; identical industrial ranges mean equivalent suitability for harsh environments. |
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 | AD7894ARZ-3 | AD7898AR-3 |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | 14 | 12 |
| Sampling Rate(Per Second) | 200k | 220k |
| Number of Inputs | 1 | 1 |
| Input Type | Single Ended | Single Ended |
| Data Interface | SPI | SPI |
| Configuration | S/H-ADC | S/H-ADC |
| Ratio - S / H: ADC | 1:1 | 1:1 |
| Number of A/D Converters | 1 | 1 |
| Architecture | SAR | SAR |
| Reference Type | External | External |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 5V | 5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key differences between the AD7894ARZ-3 and AD7898AR-3?
The AD7894ARZ-3 is a 14-bit successive-approximation ADC with a 5 V single supply and a 3 V external reference option, offering a 200 kSPS throughput in a 24-lead SOIC package. The AD7898AR-3 is a 12-bit successive-approximation ADC with a 5 V single supply and a 3 V reference, providing a 300 kSPS throughput in a 20-lead SOIC package. The primary differences are resolution (14-bit vs 12-bit), throughput (200 kSPS vs 300 kSPS), and package pin count (24-lead vs 20-lead).
Are the AD7894ARZ-3 and AD7898AR-3 pin-compatible?
No. The AD7894ARZ-3 is housed in a 24-lead SOIC package, while the AD7898AR-3 is housed in a 20-lead SOIC package. The different pin counts and pin assignments mean they are not pin-compatible and cannot be interchanged on the same PCB footprint without redesign.
Can the AD7898AR-3 be used as a direct replacement for the AD7894ARZ-3?
No. Although both are 5 V single-supply SAR ADCs with similar analog input ranges, they differ in resolution (12-bit vs 14-bit), throughput (300 kSPS vs 200 kSPS), package size (20-lead vs 24-lead SOIC), and pinout. A direct drop-in replacement is not possible; the design must be validated against the respective datasheets for timing, interface, and layout differences.
What are the analog input voltage ranges for these two ADCs?
The AD7894ARZ-3 offers a bipolar analog input range of ±10 V (with a 2.5 V reference) or ±2.5 V depending on the reference configuration, while the AD7898AR-3 provides a bipolar input range of ±10 V with a 2.5 V reference. Both devices accept bipolar inputs, but the exact full-scale range depends on the reference voltage applied and the specific grade configuration documented in the respective datasheets.
What is the maximum throughput rate of each device?
The AD7894ARZ-3 has a maximum throughput rate of 200 kSPS. The AD7898AR-3 has a maximum throughput rate of 300 kSPS. The higher throughput of the AD7898AR-3 comes with a lower resolution (12-bit) compared to the 14-bit resolution of the AD7894ARZ-3.
Do both devices support a serial interface?
Yes. Both the AD7894ARZ-3 and AD7898AR-3 provide a high-speed serial interface for connection to microprocessors and DSPs. The serial interface timing and frame format should be verified against each device's datasheet, as the resolution and conversion timing differ between the two parts.
What are the power supply requirements for the AD7894ARZ-3 and AD7898AR-3?
Both devices operate from a single 5 V supply. The AD7894ARZ-3 and AD7898AR-3 are specified for 5 V operation with a separate reference input; the AD7894ARZ-3 supports a 3 V reference option as indicated by the "-3" suffix, and the AD7898AR-3 similarly uses a 3 V reference configuration. Exact supply tolerance and current consumption should be confirmed from the manufacturer datasheets.
Which device is better suited for higher-resolution applications?
The AD7894ARZ-3 is better suited for higher-resolution applications because it provides 14-bit resolution, whereas the AD7898AR-3 provides 12-bit resolution. For applications prioritizing conversion speed over resolution, the AD7898AR-3 offers a higher 300 kSPS throughput compared to the 200 kSPS of the AD7894ARZ-3.