Part A
AD8226ARZ-R7
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5908 ПКС
- Package
- SOIC-8
- Series
- Линейные - Усилетели - Приборы, ОП Усилетели, Буферные Усилетели
Replacement verdict
Compatible functional replacement candidate
The AD8226ARZ-R7 and AD8221AR are both precision instrumentation amplifiers from Analog Devices in the same SOIC-8 package, sharing a common functional role in signal conditioning. However, they differ in gain programming architecture, bandwidth, and supply range, so the AD8226ARZ-R7 can serve as a functional candidate only after validating gain-setting configuration and application-specific performance requirements against the AD8221AR.
Gain Programming Architecture
Validation required
Bandwidth
Validation required
Package Type
High match
Supply Voltage Range
Validation required
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD8226ARZ-R7 | AD8221AR | Why it matters |
|---|---|---|---|
| Number of Amplifiers | 1 | 1 | Both are single instrumentation amplifiers, so channel count is equivalent for substitution. |
| Input Offset Voltage (max) | 200 µV | 60 µV | Lower offset improves DC accuracy; AD8221 offers tighter offset for precision applications. |
| Input Offset Voltage Drift (max) | 2 µV/°C | 0.6 µV/°C | Drift affects accuracy over temperature; AD8221 is more stable across temperature. |
| Gain Bandwidth Product | 1.5 MHz | 825 kHz | Higher bandwidth supports faster signal processing; AD8226 handles higher-frequency signals. |
| Input Bias Current (max) | 27 nA | 1.5 nA | Lower bias current reduces errors with high-impedance sources; AD8221 is better for such sensors. |
| Common-Mode Rejection Ratio (min, G=100) | 100 dB | 120 dB | Higher CMRR rejects common-mode noise better; AD8221 excels in noisy environments. |
| Supply Voltage Range | ±2.25 V to ±18 V (4.5 V to 36 V) | ±2.3 V to ±18 V (4.6 V to 36 V) | Similar supply ranges allow comparable power-rail compatibility in most designs. |
| Quiescent Supply Current (max) | 1.0 mA | 1.0 mA | Equivalent current draw means similar power budget impact for either part. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +85 °C | AD8226 supports higher ambient temperatures, important for harsh-environment designs. |
| Package | 8-Lead SOIC (R-8) | 8-Lead SOIC (R-8) | Identical package and pinout enable drop-in board-level substitution. |
Need help validating a replacement?
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD8226ARZ-R7 | AD8221AR |
|---|---|---|
| Part Status | Active | Obsolete |
| Amplifier Type | Instrumentation | Instrumentation |
| Number of Circuits | 1 | 1 |
| Slew Rate | 0.6V/µs | 2V/µs |
| Current - Input Bias | 20 nA | 500 pA |
| Voltage - Input Offset | 100 µV | 60 µV |
| Supply Current | 350µA | 900µA |
| Current - Output / Channel | 13 mA | 18 mA |
| Voltage - Supply Span (Min) | - | 4.6 V |
| Voltage - Supply Span (Max) | - | 36 V |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
| Base Product Number | - | AD8221 |
| -3 dB Bandwidth | 1.5 MHz | 825 kHz |
| Output Type | Rail-to-Rail | - |
| Voltage - Supply Span(Min) | 2.2 V | - |
| Voltage - Supply Span(Max) | 36 V | - |
Frequently asked questions
What are the key differences between the AD8226ARZ-R7 and the AD8221AR?
The AD8226ARZ-R7 is an instrumentation amplifier with a rail-to-rail output, a gain range of 1 to 1000 set by a single resistor, and a supply range of 2.7 V to 36 V. The AD8221AR is a high-performance instrumentation amplifier with a fixed gain range of 1 to 1000, a supply range of ±2.3 V to ±18 V, and a higher CMRR specification. The AD8226 is optimized for low supply voltage and rail-to-rail output swing, while the AD8221 is optimized for high CMRR and low gain error.
Are the AD8226ARZ-R7 and AD8221AR pin-compatible?
Both devices are offered in an 8-lead SOIC package (R-8 suffix), and their pinouts are functionally similar: pins 1 and 8 are gain-setting resistor terminals, pins 2 and 3 are inverting and non-inverting inputs, pin 4 is the negative supply, pin 5 is the reference, pin 6 is the output, and pin 7 is the positive supply. However, designers should verify the exact pin function assignments against the respective manufacturer datasheets before substituting one for the other on an existing PCB.
Can the AD8226ARZ-R7 directly replace the AD8221AR in an existing design?
Direct replacement is not recommended without validation. Although both are 8-lead SOIC instrumentation amplifiers with resistor-programmed gain, they differ in supply voltage range, output swing, CMRR, gain error, and bandwidth specifications. The AD8226 supports a lower minimum supply voltage (2.7 V) and rail-to-rail output, while the AD8221 offers higher CMRR and tighter gain accuracy. Circuit performance must be re-verified against the target specifications before substitution.
What is the supply voltage range for each device?
The AD8226ARZ-R7 operates from a single supply of 2.7 V to 36 V or a dual supply of ±1.35 V to ±18 V. The AD8221AR operates from a dual supply of ±2.3 V to ±18 V (or an equivalent single supply of 4.6 V to 36 V). The AD8226 therefore supports lower-voltage single-supply operation than the AD8221.
How is gain set on the AD8226ARZ-R7 and AD8221AR?
Both devices use a single external resistor connected between the gain-setting pins (pins 1 and 8) to program the gain. The gain equation for both is G = 1 + (49.4 kΩ / RG), allowing gains from 1 to 1000. The required resistor value and the resulting gain accuracy should be confirmed from the respective datasheets.
Which device offers better common-mode rejection ratio (CMRR)?
The AD8221AR is specified with a higher CMRR than the AD8226ARZ-R7. The AD8221 datasheet specifies CMRR of 80 dB minimum at G = 1 and 110 dB minimum at G = 1000 (typical values are higher). The AD8226 datasheet specifies CMRR of 80 dB minimum at G = 1 and 100 dB minimum at G = 1000. For applications requiring the highest common-mode rejection, the AD8221 is the stronger choice.
What are the output swing characteristics of each device?
The AD8226ARZ-R7 features a rail-to-rail output, allowing the output to swing close to both supply rails, which is advantageous in low-voltage single-supply systems. The AD8221AR has a more limited output swing that does not extend fully to the rails. Designs requiring maximum dynamic range near the supply rails should account for this difference.
What are the package and temperature range specifications for these parts?
Both the AD8226ARZ-R7 and the AD8221AR are supplied in an 8-lead SOIC package. The AD8226ARZ-R7 is specified over the −40 °C to +125 °C industrial temperature range. The AD8221AR is specified over the −40 °C to +85 °C temperature range. The wider specified temperature range of the AD8226ARZ-R7 may be preferable for harsh-environment applications.