Analog Devices Inc. AD8345AREZ-RL7

Overview

AD8345AREZ-RL7 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 serves as the IF transmit modulator in GSM, PCS, W-CDMA, and digital TV systems, enabling direct QPSK/QAM modulation with single-ended 50 Ω RF output.

For engineers reviewing the AD8345AREZ-RL7 datasheet, AD8345AREZ-RL7 pinout, AD8345AREZ-RL7 application, or AD8345AREZ-RL7 equivalent, key selection criteria include LO frequency range compliance (140–1000 MHz), baseband differential input drive requirements (1.2 V_p-p @ 5 V supply), sideband rejection (−42 dBc typical at 800 MHz), and thermal stability across −40°C to +85°C.

Technical Context

The AD8345AREZ-RL7 integrates a polyphase LO phase splitter that generates precise I/Q LO signals for two Gilbert-cell mixers, each driven by differential baseband currents from high-impedance voltage-to-current converters. Its bias architecture uses a Δ-V_BE-based band gap reference, enabling controlled shutdown via ENBL with 2.5 μs turn-on time.

LO inputs (LOIP/LOIN) accept −10 to 0 dBm differential drive with internal ~1.8 V DC bias and require AC coupling; baseband inputs (IBBP/IBBN/QBBP/QBBN) demand external 0.7 V DC bias and support 80 MHz bandwidth at full 1.2 V_p-p swing. The differential-to-single-ended output stage delivers 50 Ω DC-coupled RF output at VOUT with −20 dB S22 return loss.

Key Specifications

Pinout & Package

AD8345AREZ-RL7 is housed in a 16-lead TSSOP_EP package with exposed paddle for thermal dissipation. Pin 1 (IBBP) starts at the top-left corner of the top view; the exposed paddle must be soldered to PCB ground for θ_JA = 30°C/W thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD8345AREZ-RL7, AD8346ARUZ trades phase accuracy for wider LO headroom above 200 MHz, while TRF3705IRGET replaces external LO dependency with integrated synthesis at the cost of larger footprint and higher unit price-making AD8345AREZ-RL7 optimal for discrete, high-fidelity IF modulation in 140–1000 MHz infrastructure.

Availability

AD8345AREZ-RL7 is available at Aetrix Electronics and suitable for cellular infrastructure, broadband wireless access, and digital TV broadcast systems requiring stable component supply, long-term lifecycle support, and traceable sourcing for production ramp.

Supply support for AD8345AREZ-RL7 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, serving precision instrumentation, communications, and industrial markets since 1965.

The AD8345AREZ-RL7 belongs to Analog Devices' RF transceiver modulator product line, engineered specifically for high-linearity, low-phase-noise direct-conversion architectures in 3G/4G infrastructure and broadcast equipment.

FAQ

What is the minimum LO drive level required for stable operation of the AD8345AREZ-RL7?

The AD8345AREZ-RL7 specifies a minimum LO drive level of −10 dBm for reliable operation across its 140–1000 MHz range. At −10 dBm, noise floor increases by ~0.3 dB versus the recommended −2 dBm level, but phase error and sideband rejection remain within datasheet limits. Operation below −10 dBm risks degraded quadrature accuracy and increased LO leakage due to insufficient LO buffer activation.

Can the AD8345AREZ-RL7 operate with a 3.3 V supply voltage?

Yes, the AD8345AREZ-RL7 supports 2.7 V to 5.5 V single-supply operation, including 3.3 V. At 3.3 V, output power drops to approximately −1 dBm at 800 MHz (vs. +2.5 dBm at 5 V), and baseband input swing must be reduced to ~400 mV_p-p to avoid clipping. All other specifications-including phase error, noise floor, and enable timing-remain valid per the datasheet's 3.3 V test conditions.

How is LO leakage compensated in the AD8345AREZ-RL7?

LO leakage in the AD8345AREZ-RL7 is reduced by applying programmable DC offset voltages to the I and Q differential inputs-not by adjusting the common-mode bias. Using a DAC with dc-coupled outputs, offset codes are tuned until LO feedthrough reaches a minimum (typically <−65 dBm). This compensation holds across temperature and is validated in Figure 10 of the AD8345 datasheet Rev. B.

Does the AD8345AREZ-RL7 require external baluns for LO or baseband inputs?

The AD8345AREZ-RL7 does not require external baluns for baseband inputs, as it accepts fully differential drive directly. For LO inputs, a balun (e.g., M/A-COM ETC1-1-13) is recommended to achieve optimal −42 dBm LO leakage, but single-ended LO drive is supported with ~3–5 dB degradation in leakage performance. The LOIN/LOIP pins have internal DC bias and must be AC-coupled regardless of drive method.

What is the thermal resistance (θ_JA) of the AD8345AREZ-RL7 in its TSSOP_EP package?

The AD8345AREZ-RL7 has θ_JA = 30°C/W when the exposed paddle is soldered to a minimum 1-in² copper pad on the PCB, and θ_JA = 95°C/W if the paddle is left unconnected. The datasheet specifies maximum junction temperature of 150°C and operating range of −40°C to +85°C; thermal design must ensure junction temperature remains below 150°C under worst-case 78 mA active current and ambient conditions.