Part A
AD8307AR
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2581 ПКС
- Package
- SOIC-8
- Series
- Линейные - Усилители - Специальное назначение
Replacement verdict
Not a drop-in replacement
The AD8307AR and AD8306AR-REEL are not drop-in replacements for one another. Although both are logarithmic amplifiers in the same SOIC-8 package, they differ fundamentally in signal detection architecture, dynamic range, output interface, and operating frequency range, so substituting one for the other requires circuit redesign and full validation.
Different detection architecture
Different dynamic range
Different output interface
Different frequency range
Parts at a glance
Part B
AD8306AR-REEL
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 4695 ПКС
- Package
- SOIC-16
- Series
- Линейные - Усилители - Специальное назначение
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD8307AR | AD8306AR-REEL | Why it matters |
|---|---|---|---|
| Function | Logarithmic amplifier / RSSI detector (demodulating logarithmic amplifier) | Limiting logarithmic amplifier with RSSI (limiting log amp) | The core signal-processing function differs; the AD8306 includes limiting amplifier outputs for phase/frequency detection, while the AD8307 is a pure log detector, so they are not drop-in substitutes. |
| Frequency range | DC to 500 MHz | 5 MHz to 400 MHz | Operating bandwidth determines which input signals each part can handle; the AD8307 extends to DC while the AD8306 has a defined lower frequency limit. |
| Dynamic range | 92 dB | 100 dB | Dynamic range sets the span of input power levels over which the log output remains usable; a larger range allows detection of weaker and stronger signals. |
| Logarithmic slope | 25 mV/dB | 20 mV/dB | Slope determines the output voltage change per dB of input; different slopes require recalibration of downstream ADC scaling and setpoint thresholds. |
| Logarithmic intercept | -84 dBm (at 100 MHz) | -95 dBm (at 100 MHz) | Intercept defines the reference point of the log transfer function; a different intercept shifts the absolute power reading and affects calibration. |
| Supply voltage | 2.7 V to 5.5 V | 2.7 V to 6.5 V | Supply range affects compatibility with the system rail; the AD8306 tolerates a higher maximum supply voltage. |
| Supply current | 7.5 mA (typical) | 16 mA (typical) | Quiescent current impacts power budget and thermal design; the AD8306 draws roughly twice the current of the AD8307. |
| Package | 8-lead SOIC | 16-lead SOIC | Different package and pin count mean the parts are not footprint-compatible and require board layout changes. |
| Limiting amplifier outputs | Not available | Available (differential limiter outputs) | The AD8306 provides limited-output signals usable for phase/frequency demodulation, a function the AD8307 lacks, affecting system architecture. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD8307AR | AD8306AR-REEL |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Obsolete | Obsolete |
| Type | Logarithmic Amplifier | Limiting-Logarithmic Amplifier |
| Applications | Receiver Signal Strength Indication (RSSI) | Receiver Signal Strength Indication (RSSI) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the primary functional differences between the AD8307AR and AD8306AR-REEL?
The AD8307AR is a 500 MHz, 92 dB logarithmic amplifier (log amp) designed for RSSI and signal strength measurement, providing a DC output proportional to the log of the input voltage. The AD8306AR-REEL is a 400 MHz, 100 dB limiting logarithmic amplifier that includes an on-chip limiter output and RSSI, intended for received signal strength indication and phase/frequency demodulation in FM/FSK receivers. The AD8306AR-REEL is supplied in tape-and-reel packaging, whereas the AD8307AR is typically supplied in tubes.
Are the AD8307AR and AD8306AR-REEL pin-compatible?
No. Both devices are offered in 8-lead SOIC packages, but their pin functions differ. The AD8307AR provides a single logarithmic output and does not include a limiter output, while the AD8306AR-REEL includes additional limiter outputs and a different internal signal path. Pin assignments and external component requirements are not interchangeable, so the PCB layout must be designed specifically for each part.
Can the AD8307AR be used as a direct replacement for the AD8306AR-REEL in an existing design?
No, a direct replacement is not possible without design changes. The AD8306AR-REEL provides a limiter output and a different logarithmic slope and intercept, and its external interface and pinout differ from the AD8307AR. Substitution requires verifying supply voltage, input range, output scaling, and PCB layout against the respective manufacturer datasheets.
What are the specified operating frequency ranges for these two log amplifiers?
According to Analog Devices datasheets, the AD8307AR operates from DC to 500 MHz, while the AD8306AR-REEL operates from DC to 400 MHz. Both are specified for RF signal strength measurement within these ranges.
How do the logarithmic dynamic ranges of the AD8307AR and AD8306AR-REEL compare?
The AD8307AR provides a nominal 92 dB dynamic range, while the AD8306AR-REEL provides a nominal 100 dB dynamic range. These figures are specified by Analog Devices and apply to the logarithmic output over the rated frequency range.
What supply voltage and current requirements apply to the AD8307AR and AD8306AR-REEL?
Both devices operate from a single supply in the range of 2.7 V to 5.5 V, as specified in their Analog Devices datasheets. Typical supply current for the AD8307AR is approximately 7.5 mA, and for the AD8306AR-REEL approximately 18 mA. Designers should confirm exact limits and conditions in the latest datasheet revision.
What is the significance of the REEL suffix on the AD8306AR-REEL?
The REEL suffix indicates tape-and-reel packaging, which is intended for automated pick-and-place assembly in high-volume production. The AD8307AR is commonly supplied in tube packaging. The electrical specifications of the AD8306AR-REEL are identical to the standard AD8306AR; only the packaging and ordering quantity differ.
Which device is more suitable for FM/FSK demodulation applications?
The AD8306AR-REEL is more suitable for FM/FSK demodulation because it includes a limiter output that provides a constant-amplitude signal for phase or frequency detection, in addition to the RSSI output. The AD8307AR provides only a logarithmic RSSI output and does not include a limiter output, making it better suited to pure signal strength measurement.