Part A
AD8307ARZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6156 PCS
- Package
- SOIC-8
- Series
- Linear - Amplifiers - Special Purpose
Replacement verdict
Not a drop-in replacement
The AD8307ARZ and AD8306AR-REEL are not drop-in replacements for one another. Although both are logarithmic amplifiers in SOIC-8 packages, they differ fundamentally in signal path architecture, output interface, dynamic range, and supply requirements, so substituting one for the other requires circuit redesign and full validation.
Different output interface
Different signal path architecture
Different dynamic range
Different supply requirements
Parts at a glance
Part B
AD8306AR-REEL
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 4695 PCS
- Package
- SOIC-16
- Series
- Linear - Amplifiers - Special Purpose
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD8307ARZ | AD8306AR-REEL | Why it matters |
|---|---|---|---|
| Function Type | Logarithmic Amplifier / RSSI Detector | Logarithmic Amplifier / Limiting Amplifier with RSSI | Defines the core signal-processing role; the AD8306 adds a limiting output stage, so it is not a drop-in for pure RSSI detection applications. |
| Frequency Range | DC to 500 MHz | 5 MHz to 400 MHz | Determines the input signal bandwidth the device can handle; the AD8307 extends to DC while the AD8306 has a lower frequency floor. |
| Dynamic Range | 92 dB | 100 dB | Sets the span of input power levels over which accurate logarithmic detection is maintained; wider range improves measurement flexibility. |
| Logarithmic Slope | 25 mV/dB | 20 mV/dB | Determines the output voltage change per dB of input; affects scaling in the downstream ADC or control loop. |
| Logarithmic Intercept | -84 dBm (at 100 MHz) | -95 dBm (at 100 MHz) | Defines the reference point of the log transfer function; different intercepts require recalibration when substituting parts. |
| Supply Voltage | 2.7 V to 5.5 V | 2.7 V to 6.5 V | Must match the system power rail; the AD8306 tolerates a slightly higher maximum supply. |
| Supply Current | 7.5 mA (typical) | 16 mA (typical) | Affects power budget and thermal design; the AD8306 draws roughly twice the current. |
| Limiting Output | No | Yes | A limiting output provides a constant-amplitude signal for phase/frequency demodulation; its absence in the AD8307 limits direct substitution in such circuits. |
| Package | 8-Lead SOIC | 16-Lead SOIC | Footprint and pin count differ, so board layout changes are required when swapping between the two devices. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Confirms both parts suit the same industrial temperature environments for reliable operation. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD8307ARZ | AD8306AR-REEL |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | 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 AD8307ARZ and AD8306AR-REEL?
The AD8307ARZ is a complete 500 MHz monolithic demodulating logarithmic amplifier providing a 92 dB dynamic range and a nominal 25 mV/dB logarithmic slope. The AD8306AR-REEL is a 400 MHz limiting logarithmic amplifier that provides both a logarithmic output and a limited output, with a 100 dB dynamic range and a nominal 20 mV/dB slope. The AD8307ARZ is optimized for RSSI and signal strength measurement, while the AD8306AR-REEL is optimized for received signal strength indication with an additional limiting amplifier output for phase/frequency demodulation.
Are the AD8307ARZ and AD8306AR-REEL pin-compatible?
No. Both devices are offered in an 8-lead SOIC package, but their pin functions differ. The AD8307ARZ pinout includes IN+, IN-, ENB, VPS1, VPS2, LOG OUT, OFS, and COMM. The AD8306AR-REEL pinout includes IN+, IN-, ENB, VPS1, VPS2, LOG OUT, LIM OUT, and COMM. The LIM OUT pin on the AD8306AR-REEL replaces the OFS pin on the AD8307ARZ, so the two are not directly interchangeable without circuit modification.
What is the difference in dynamic range and logarithmic slope between the two parts?
The AD8307ARZ provides a 92 dB dynamic range with a nominal logarithmic slope of 25 mV/dB. The AD8306AR-REEL provides a 100 dB dynamic range with a nominal logarithmic slope of 20 mV/dB. These differences affect the scaling of the logarithmic output voltage versus input signal level and must be accounted for in system calibration.
What are the maximum operating frequencies of the AD8307ARZ and AD8306AR-REEL?
The AD8307ARZ is specified for operation up to 500 MHz. The AD8306AR-REEL is specified for operation up to 400 MHz. Designs requiring operation above 400 MHz should use the AD8307ARZ, while the AD8306AR-REEL is limited to applications at or below 400 MHz.
Does the AD8306AR-REEL provide an additional output that the AD8307ARZ does not?
Yes. The AD8306AR-REEL includes a limited output (LIM OUT) in addition to the logarithmic output (LOG OUT). This limiting output provides a constant-amplitude signal for phase and frequency demodulation. The AD8307ARZ provides only the logarithmic output and does not include a limiting amplifier output.
What supply voltage and current consumption should be expected for each device?
Both the AD8307ARZ and AD8306AR-REEL operate from a single supply ranging from 2.7 V to 5.5 V. The AD8307ARZ typically draws approximately 7.5 mA of supply current. The AD8306AR-REEL typically draws approximately 18 mA of supply current. Power budget and thermal considerations should be evaluated accordingly when selecting between the two.
Can the AD8307ARZ and AD8306AR-REEL be used interchangeably in an existing design?
No. Although both are 8-lead SOIC logarithmic amplifiers, they differ in pinout (OFS versus LIM OUT), dynamic range (92 dB versus 100 dB), logarithmic slope (25 mV/dB versus 20 mV/dB), maximum frequency (500 MHz versus 400 MHz), and supply current (approximately 7.5 mA versus 18 mA). Direct substitution is not possible without verifying and modifying the surrounding circuit, calibration, and power budget against the respective manufacturer datasheets.