Analog Devices Inc. AD8345ARE-REEL7

Overview

AD8345ARE-REEL7 from Analog Devices is a silicon RFIC quadrature modulator operating from 140 MHz to 1000 MHz, delivering +2.5 dBm P1dB output power at 800 MHz with −155 dBm/Hz noise floor, 0.5° RMS phase error, and 0.2 dB amplitude balance. It functions as the IF transmit modulator in digital wireless transceivers, enabling direct QPSK/QAM modulation for W-CDMA, GSM, and digital TV systems.

For engineers reviewing the AD8345ARE-REEL7 datasheet, AD8345ARE-REEL7 pinout, AD8345ARE-REEL7 application, or AD8345ARE-REEL7 equivalent, key selection criteria include LO frequency range compliance, differential baseband input drive requirements (1.2 V_p-p @ 5 V supply), RF output return loss (−20 dB), sideband suppression (−42 dBc @ 800 MHz), and enable timing (2.5 μs turn-on).

Technical Context

The AD8345ARE-REEL7 integrates a polyphase phase splitter to generate precise I/Q LO signals, two Gilbert-cell double-balanced mixers, and a differential-to-single-ended converter delivering 50 Ω DC-coupled RF output at VOUT. Its bias architecture uses a Δ-V_BE-based band gap reference controlled by the ENBL pin.

LO inputs (LOIP/LOIN) require AC coupling and accept −10 dBm to 0 dBm drive; baseband inputs (IBBP/IBBN/QBBP/QBBN) are high-impedance differential voltage interfaces with 80 MHz bandwidth and 0.7 V DC bias requirement. The device draws 50–78 mA active current and supports 2.7 V to 5.5 V single-supply operation.

Key Specifications

Pinout & Package

AD8345ARE-REEL7 is housed in a 16-lead TSSOP_EP package with exposed paddle for thermal dissipation (θ_JA = 30°C/W when soldered down). Pin assignments follow standard Analog Devices RFIC layout: differential I/Q inputs on pins 1–2 and 15–16, LO inputs on pins 5–6, RF output on pin 11, dual supply pins (VPS1/VPS2) on pins 7/12, ground pins (COM1–COM3) distributed across pins 3/4/9/10/13/14, and enable on pin 8.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quadrature modulator applications.

Compared with AD8346ARUZ, AD8345ARE-REEL7 delivers 1 dB higher linear output power and better noise floor (−155 vs. −152 dBm/Hz), making it preferable for infrastructure-grade transmitters; versus TRF3705IRGET, AD8345ARE-REEL7 offers superior phase accuracy (0.5° vs. 1.2° RMS) at lower cost and smaller footprint, but lacks integrated frequency synthesis.

Availability

AD8345ARE-REEL7 is available at Aetrix Electronics and suitable for cellular base station transceivers, fixed broadband wireless access units, wireless LAN infrastructure, and digital TV/CATV modulators requiring stable component supply across extended temperature ranges (−40°C to +85°C).

Supply support for AD8345ARE-REEL7 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices is a global leader in high-performance analog, mixed-signal, and RF ICs, founded in 1965 and headquartered in Norwood, MA.

The AD8345ARE-REEL7 belongs to Analog Devices' RF transceiver modulator product line, engineered specifically for high-linearity, low-phase-noise direct-conversion architectures in wireless infrastructure and broadcast equipment.

FAQ

What is the recommended LO drive level for optimal noise performance of the AD8345ARE-REEL7?

The AD8345ARE-REEL7 achieves its lowest noise floor (−155 dBm/Hz) at an LO drive level of −2 dBm. Reducing LO power to −10 dBm increases noise floor by ~0.3 dB, while exceeding 0 dBm degrades linearity. This −2 dBm level is specified with 50 Ω source impedance and applies across the full 140–1000 MHz operating band.

Can the AD8345ARE-REEL7 operate from a 2.7 V supply, and how does that affect output power?

Yes, the AD8345ARE-REEL7 operates from 2.7 V to 5.5 V. At 2.7 V, baseband input swing must be reduced to 200 mV_p-p to avoid clipping, resulting in ~15 dB lower SSB output power versus 5 V operation. Figure 3 in the datasheet quantifies this trade-off across frequency, confirming −16 dBm typical output at 800 MHz with 2.7 V supply.

How is LO leakage compensated in the AD8345ARE-REEL7, and what external components are required?

LO leakage in the AD8345ARE-REEL7 is reduced by applying DC offset voltages to the I/Q differential inputs-not by adjusting the 0.7 V common-mode bias. This requires DC-coupled connection from a programmable DAC (e.g., AD9779) to IBBP/IBBN/QBBP/QBBN pins. No additional passive components are needed beyond standard decoupling capacitors on VPS1/VPS2.

What is the function of the COM1, COM2, and COM3 pins on the AD8345ARE-REEL7, and how should they be connected?

COM1 is the ground return for the LO phase splitter and buffers; COM2 serves the output stage; COM3 grounds the baseband V-to-I converters and mixer cores. All must connect to a low-impedance, solid ground plane-ideally via separate vias-to prevent coupling between LO, baseband, and RF sections. Mixing these grounds degrades sideband suppression and increases LO leakage.

Does the AD8345ARE-REEL7 support single-ended baseband input, and if so, what interface circuitry is recommended?

The AD8345ARE-REEL7 requires differential baseband inputs but supports single-ended drive via external differential amplifiers. Analog Devices recommends the AD8132 or AD8138 configured for unity gain, which provide 50 Ω input impedance and add the required 0.7 V common-mode bias. Figure 30 in the datasheet shows a complete implementation using two AD8132s with resistor networks for impedance matching.