Part A
AD8346ARU
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2410 PCS
- Package
- TSSOP-16
- Series
- RF Modulators
Replacement verdict
Not a drop-in replacement
The AD8347ARUZ and AD8346ARU are not drop-in replacements for one another. Although both are wideband quadrature demodulator/modulator ICs from Analog Devices in similar TSSOP packages, they differ fundamentally in signal-chain function, frequency range, and baseband output architecture, so substituting one for the other requires circuit redesign and full validation.
Different signal-chain function
Different frequency range
Different baseband output type
Different gain/control architecture
Parts at a glance
Part B
AD8347ARUZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3427 PCS
- Package
- TSSOP-28
- Series
- RF Demodulators
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD8347ARUZ | AD8346ARU | Why it matters |
|---|---|---|---|
| Function | Quadrature demodulator with integrated baseband amplifiers and AGC | Quadrature modulator | These are fundamentally different signal-chain functions (demodulation vs. modulation), so they are not functionally substitutable in a given circuit. |
| Frequency Range | 0.8 GHz to 2.7 GHz | 0.8 GHz to 2.5 GHz | The operating band determines which RF systems each part can support; the demodulator extends slightly higher in frequency. |
| Signal Path Direction | RF input to baseband I/Q output (receive path) | Baseband I/Q input to RF output (transmit path) | Direction of signal conversion dictates whether the device is used in a receiver or transmitter chain. |
| Integrated Baseband Amplifiers / AGC | Yes, with automatic gain control | No | Integrated baseband gain and AGC simplify receiver design and reduce external component count; the modulator lacks these. |
| Output / Input Interface | Differential I/Q baseband outputs | Differential I/Q baseband inputs | The interface type must match the surrounding baseband circuitry (ADC for demodulator, DAC for modulator). |
| LO Input Frequency Range | 0.8 GHz to 2.7 GHz | 0.8 GHz to 2.5 GHz | The local oscillator must fall within the supported range for proper mixing operation. |
| Supply Voltage | 5 V | 3 V | Different supply requirements affect power rail design and compatibility with the rest of the system. |
| Package | 28-lead TSSOP | 16-lead TSSOP | Package footprint and pin count affect PCB layout and are not interchangeable between the two parts. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD8346ARU | AD8347ARUZ |
|---|---|---|
| Part Status | Obsolete | Active |
| Function | Modulator | Demodulator |
| LO Frequency | 800MHz ~ 2.5GHz | 800MHz ~ 2.7GHz |
| RF Frequency | 800MHz ~ 2.5GHz | 800MHz ~ 2.7GHz |
| P1d B | -3dBm | -30dBm |
| Noise Floor | -147dBm/Hz | - |
| Output Power | -6dBm | - |
| Supply Current | 55 mA | 80 mA |
| Voltage - Supply | 2.7V ~ 5.5V | 2.7V ~ 5.5V |
| Test Frequency | 1.9GHz | - |
| Gain | - | 39.5dB |
| Noise Figure | - | 11dB |
| Mounting Type | - | Surface Mount |
Frequently asked questions
What are the primary functional differences between the AD8347ARUZ and the AD8346ARU?
The AD8347ARUZ is a broadband quadrature demodulator with integrated baseband amplifiers and a phase detector, operating from 800 MHz to 2.7 GHz. The AD8346ARU is a quadrature modulator operating from 800 MHz to 2.5 GHz. One is a receive-path demodulator; the other is a transmit-path modulator, so they are not functionally interchangeable.
Do the AD8347ARUZ and AD8346ARU use the same package and pinout?
Both devices are supplied in a 16-lead TSSOP package (RU suffix). However, their pin functions differ because one is a demodulator and the other is a modulator, so the PCB land pattern may be similar but the pin assignments are not interchangeable.
What frequency ranges do the AD8347ARUZ and AD8346ARU support?
The AD8347ARUZ operates over an RF input range of 800 MHz to 2.7 GHz. The AD8346ARU operates over an RF output range of 800 MHz to 2.5 GHz. The overlapping band is 800 MHz to 2.5 GHz, but the AD8347ARUZ extends higher in frequency.
Can the AD8347ARUZ and AD8346ARU be used together in the same radio design?
Yes. Because the AD8347ARUZ is a demodulator for the receive path and the AD8346ARU is a modulator for the transmit path, they can be used together in a transceiver architecture within their overlapping 800 MHz to 2.5 GHz frequency range, subject to the system's gain, linearity, and LO requirements.
What are the supply voltage requirements for the AD8347ARUZ and AD8346ARU?
Both devices operate from a single 5 V supply. Designers should verify the exact specified supply range and current consumption in the respective manufacturer datasheets, as the demodulator and modulator have different internal architectures and power budgets.
Are the AD8347ARUZ and AD8346ARU drop-in replacements for each other?
No. They perform opposite signal-path functions (demodulation versus modulation), have different pin assignments, and different external component requirements. A direct substitution is not possible without redesigning the surrounding RF and baseband circuitry.
What baseband interfaces do the AD8347ARUZ and AD8346ARU provide?
The AD8347ARUZ provides differential baseband I and Q outputs with integrated variable-gain amplifiers. The AD8346ARU accepts differential baseband I and Q inputs for quadrature modulation. The interface direction and signal levels differ, so baseband driving and receiving circuits must be designed accordingly.