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
Not a drop-in replacement
The AD7894ARZ-3 and AD7899BR-1 are not drop-in replacements for one another. The AD7894ARZ-3 is a 14-bit, single-channel SAR ADC offered in a 24-lead SOIC package, while the AD7899BR-1 is a 14-bit, single-channel SAR ADC in a 28-lead SSOP package with a different analog input range and reference configuration. Designers must account for differences in package footprint, input voltage range, and reference architecture before considering substitution.
Different package footprint
Different analog input range
Different reference configuration
Different pinout
Parts at a glance
Part B
AD7899BR-1
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 4423 個数
- Package
- SOIC-28
- 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 | AD7899BR-1 | Why it matters |
|---|---|---|---|
| Resolution | 14 bit | 14 bit | Both are 14-bit ADCs, so nominal resolution is equivalent and neither offers a bit-depth advantage for substitutability. |
| Number of Input Channels | 1 (single-ended) | 1 (single-ended) | Channel count determines how many signals can be digitized; both being single-channel means they serve the same single-input topology. |
| Sampling Rate | 200 kSPS | 400 kSPS | The AD7899BR-1 offers twice the throughput, which matters for higher-bandwidth signals or faster control loops. |
| Input Voltage Range | ±2.5 V (bipolar) | ±2.5 V (bipolar) | Matching input ranges means the same analog front-end scaling can be reused without redesign. |
| Supply Voltage | 5 V single supply | 5 V single supply | Identical supply requirements simplify power-rail compatibility when swapping parts. |
| Interface Type | Serial (SPI/QSPI compatible) | Parallel | Serial versus parallel interface is a major architectural difference affecting pinout, board layout, and host controller requirements. |
| Package | 8-lead SOIC | 28-lead SOIC | Different package footprints prevent direct drop-in replacement and require PCB redesign. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Equivalent temperature ratings mean both suit the same industrial environments. |
| Power Consumption | ~20 mW (typ) | ~100 mW (typ) | The AD7894ARZ-3 is significantly lower power, which matters for thermally constrained or battery-influenced designs. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7894ARZ-3 | AD7899BR-1 |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | 14 | 14 |
| Sampling Rate(Per Second) | 200k | 400k |
| Number of Inputs | 1 | 1 |
| Input Type | Single Ended | Single Ended |
| Data Interface | SPI | Parallel |
| 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, Internal |
| 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 AD7899BR-1?
The AD7894ARZ-3 is a 14-bit successive-approximation ADC with a 5 V single supply and a 0 V to +2.5 V input range, housed in a 24-lead SOIC. The AD7899BR-1 is a 14-bit ADC with a 5 V supply and a ±10 V bipolar input range, offered in a 28-lead SSOP. They differ in input range, package, and pinout, so they are not pin-compatible substitutes.
Do the AD7894ARZ-3 and AD7899BR-1 have the same resolution and throughput?
Both devices provide 14-bit resolution. The AD7894ARZ-3 offers a 200 kSPS throughput rate, while the AD7899BR-1 provides a 400 kSPS throughput rate, so the AD7899BR-1 is faster.
Are the input voltage ranges of the AD7894ARZ-3 and AD7899BR-1 compatible?
No. The AD7894ARZ-3 accepts a unipolar 0 V to +2.5 V input range, whereas the AD7899BR-1 accepts a bipolar ±10 V input range. Signal conditioning must be adjusted when migrating between these parts.
Can the AD7894ARZ-3 be used as a drop-in replacement for the AD7899BR-1?
No. The two devices have different package types (24-lead SOIC versus 28-lead SSOP), different pinouts, different input ranges, and different throughput rates. A direct drop-in replacement is not possible without PCB and signal-chain redesign.
What supply voltage do the AD7894ARZ-3 and AD7899BR-1 require?
Both devices operate from a single 5 V supply. The AD7894ARZ-3 is specified for a 5 V supply, and the AD7899BR-1 is also specified for a 5 V supply.
What interface do the AD7894ARZ-3 and AD7899BR-1 provide?
Both ADCs provide a high-speed parallel interface for connection to microprocessors and DSPs. The AD7894ARZ-3 offers a 14-bit parallel output, and the AD7899BR-1 also provides a 14-bit parallel output.
Which part is better suited for bipolar signal acquisition?
The AD7899BR-1 is better suited for bipolar signal acquisition because it provides a ±10 V bipolar input range. The AD7894ARZ-3 has a unipolar 0 V to +2.5 V input range and would require external level shifting for bipolar signals.