Part A
AD9225ARS
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7539 PCS
- Package
- SSOP-28
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Not a drop-in replacement
The AD9225ARS and AD9221AR are both 12-bit monolithic analog-to-digital converters from Analog Devices, but they differ fundamentally in sampling rate, power consumption, and dynamic performance, so the AD9221AR cannot serve as a direct substitute for the AD9225ARS in existing designs. The AD9225ARS delivers a 25 MSPS conversion rate while the AD9221AR is limited to 1.5 MSPS, and the two devices also diverge in supply current, analog input bandwidth, and signal-to-noise performance. A board-level redesign with revalidation of timing, clocking, and power budgets would be required before considering the AD9221AR in place of the AD9225ARS.
Different sampling rate
Different power consumption
Different dynamic performance
Different input bandwidth
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD9225ARS | AD9221AR | Why it matters |
|---|---|---|---|
| Resolution | 12 bits | 12 bits | Both converters provide 12-bit resolution, so quantization granularity is equivalent for signal-chain design. |
| Sampling Rate | 25 MSPS | 1.5 MSPS | Maximum sample rate determines the input bandwidth the ADC can support; the AD9225ARS is far faster and not a drop-in for high-speed Nyquist applications. |
| Input Type | Differential | Single-ended | Differential inputs improve noise immunity and dynamic range, while single-ended inputs simplify front-end drive requirements. |
| Supply Voltage | 5 V (single supply) | 5 V (single supply) | Both operate from a single 5 V rail, so power-supply architecture is compatible between the two parts. |
| Power Consumption | ~280 mW typical | ~60 mW typical | Lower power dissipation affects thermal design and supply sizing; the AD9221AR is significantly more power-efficient. |
| SNR (Signal-to-Noise Ratio) | ~71 dB | ~70 dB | SNR indicates achievable dynamic range; similar values mean comparable noise performance for a given input signal. |
| Package | 28-lead SSOP | 28-lead SOIC | Different package footprints require board layout changes; the parts are not physically interchangeable without redesign. |
| Output Interface | Parallel CMOS | Parallel CMOS | Both provide parallel CMOS outputs, so digital interface timing and bus width are compatible. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Identical industrial temperature ratings mean both suit the same environmental conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD9225ARS | AD9221AR |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | 12 | 12 |
| Sampling Rate(Per Second) | 25M | 1.5M |
| Number of Inputs | 1 | 1 |
| Input Type | Differential, Single Ended | Differential, Single Ended |
| Data Interface | Parallel | Parallel |
| Configuration | S/H-ADC | S/H-ADC |
| Ratio - S / H: ADC | 1:1 | 1:1 |
| Number of A/D Converters | 1 | 1 |
| Architecture | Pipelined | Pipelined |
| Reference Type | External, Internal | Internal |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 2.85V ~ 5.25V | 2.7V ~ 5.25V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key differences between the AD9225ARS and AD9221AR?
The AD9225ARS is a 12-bit, 25 MSPS analog-to-digital converter, while the AD9221AR is a 12-bit, 1.5 MSPS ADC. Both are monolithic pipelined ADCs from Analog Devices, but the AD9225ARS offers a significantly higher sampling rate and is supplied in a 28-lead SSOP package, whereas the AD9221AR is supplied in a 28-lead SOIC package.
Are the AD9225ARS and AD9221AR pin-compatible?
No. The AD9225ARS is packaged in a 28-lead SSOP (RS suffix) and the AD9221AR is packaged in a 28-lead SOIC (R suffix). Although both have 28 pins, the package footprints and land patterns differ, so they are not drop-in replacements on the same PCB without layout changes.
What is the maximum sampling rate of each device?
The AD9225ARS supports a maximum sampling rate of 25 MSPS. The AD9221AR supports a maximum sampling rate of 1.5 MSPS. Designs requiring higher throughput should use the AD9225ARS, while lower-speed applications may use the AD9221AR.
Do both converters provide 12-bit resolution?
Yes. Both the AD9225ARS and AD9221AR are 12-bit analog-to-digital converters, providing 12-bit resolution over their respective input ranges and sampling rates.
What are the typical power consumption figures for these ADCs?
The AD9225ARS typically dissipates about 280 mW from a single 5 V supply. The AD9221AR typically dissipates about 70 mW from a single 5 V supply. The lower power of the AD9221AR reflects its lower maximum sampling rate.
What input voltage range do the AD9225ARS and AD9221AR support?
Both devices are designed for a 2 V peak-to-peak differential input span, with on-chip reference and sample-and-hold circuitry. The input configuration and reference options should be verified against the respective manufacturer datasheets for the specific operating mode.
Can the AD9221AR be used as a direct replacement for the AD9225ARS in an existing design?
No. Beyond the package difference (SOIC vs SSOP), the AD9221AR has a much lower maximum sampling rate (1.5 MSPS vs 25 MSPS). A design requiring 25 MSPS cannot use the AD9221AR, and the PCB land pattern must be changed to accommodate the different package.
What supply voltage do these converters require?
Both the AD9225ARS and AD9221AR operate from a single 5 V analog supply. Designers should confirm all supply, reference, and clock requirements against the official Analog Devices datasheets for each part before finalizing a design.