Analog Devices Inc. ADF4111BRUZ-RL

Overview

ADF4111BRUZ-RL from Analog Devices is a 1.2 GHz RF PLL frequency synthesizer IC used as a local oscillator in wireless transceivers. It features a dual-modulus prescaler (8/9, 16/17, 32/33, 64/65), programmable charge pump current (625 µA to 5 mA), 3-wire serial interface, and operates from 2.7 V to 5.5 V. It supports GSM/PCS/CDMA base station and handset RF upconversion/downconversion.

For engineers reviewing the ADF4111BRUZ-RL datasheet, ADF4111BRUZ-RL pinout, ADF4111BRUZ-RL application, or ADF4111BRUZ-RL equivalent, key selection criteria include RF input frequency range (80 MHz–1.2 GHz at 3 V), phase noise performance (−87 dBc/Hz @ 1 kHz offset, 900 MHz), lock detect capability, charge pump supply flexibility (VP ≥ AVDD), and industrial temperature rating (−40°C to +85°C).

Technical Context

The ADF4111BRUZ-RL implements a digital phase-frequency detector (PFD) with analog charge pump, 14-bit R counter, 6-bit A counter, and 13-bit B counter driving a P/P+1 dual-modulus prescaler to realize N = BP + A division. Its architecture enables precise fractional-N synthesis when paired with an external loop filter and VCO.

It supports both hardware and software power-down modes, offers analog and digital lock detection, and allows independent VP supply (up to 6.0 V) for extended VCO tuning voltage in 3 V systems - critical for wide-range RF front-end design in cellular infrastructure.

Key Specifications

Pinout & Package

TSSOP-16 package (RUZ suffix), thermally enhanced with exposed paddle connected to AGND. Pin count and layout match industry-standard footprint for drop-in compatibility in RF layout designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF PLL synthesizer applications.

Compared with ADF4111BRUZ-RL, ADF4113BRUZ extends frequency coverage to 4 GHz at higher power, while LMX2531LQ1580E trades external VCO flexibility for integration and smaller footprint - making ADF4111BRUZ-RL optimal for scalable, multi-band, externally tuned RF platforms.

Availability

ADF4111BRUZ-RL is available at Aetrix Electronics and suitable for GSM/PCS base stations, wireless handsets, and communications test equipment requiring stable component supply, full traceability, and long-term industrial-grade availability.

Supply support for ADF4111BRUZ-RL 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 ADF411x family was designed specifically for wireless infrastructure and handset local oscillator synthesis, emphasizing low phase noise, flexible power supply architecture, and robust lock detection for mission-critical RF timing.

FAQ

What is the maximum RF input frequency supported by the ADF4111BRUZ-RL?

The ADF4111BRUZ-RL supports an RF input frequency range of 0.08 GHz to 1.2 GHz under 3 V operation, and up to 1.4 GHz at 5 V supply. This makes it suitable for GSM (900/1800 MHz), PCS (1900 MHz), and CDMA (800/1900 MHz) bands. The device uses a dual-modulus prescaler to divide high-frequency inputs before processing by the PFD, ensuring reliable operation within its specified range. Always verify slew rate (>50 V/µs at 5 V) for lower-frequency inputs.

Does the ADF4111BRUZ-RL require an external loop filter?

Yes, the ADF4111BRUZ-RL requires an external passive loop filter between the CP pin and the VCO tuning input. It does not integrate a filter or VCO. The charge pump outputs programmable ±ICP current, which must be converted to a stable tuning voltage via an RC network or active filter. Filter design depends on target loop bandwidth, phase margin, and reference spur suppression - values like RSET = 4.7 kΩ and ICP = 5 mA directly impact component selection.

How does the separate VP supply benefit RF system design with the ADF4111BRUZ-RL?

The separate VP supply (AVDD ≤ VP ≤ 6.0 V) allows the ADF4111BRUZ-RL's charge pump to generate up to 6 V tuning voltage even when the core logic runs at 3 V - eliminating need for external charge pumps or level shifters. This simplifies RF front-end design for wide-tuning-range VCOs used in multiband base stations. In the ADF4111BRUZ-RL, VP decoupling is critical: poor VP bypassing directly increases reference spurs and degrades phase noise.

Can the ADF4111BRUZ-RL operate in hardware power-down mode, and how is it controlled?

Yes, the ADF4111BRUZ-RL supports hardware power-down via the CE (chip enable) pin: a logic low forces the charge pump into high-impedance state and disables internal circuitry, reducing supply current to 1 µA typical. This mode is independent of the F2 power-down bit, enabling fast, deterministic shutdown in battery-powered or thermally constrained systems. CE must be driven cleanly - noise or slow edges can cause metastability or partial wake-up.

What are the key differences between ADF4111BRUZ-RL and ADF4110BRUZ in terms of RF performance?

The ADF4111BRUZ-RL supports up to 1.2 GHz RF input (vs. 550 MHz for ADF4110BRUZ), uses the same TSSOP-16 package and 3-wire interface, and shares identical register structure and lock detect functionality. Its higher frequency capability targets PCS/DCS/CDMA bands, while ADF4110BRUZ is optimized for sub-600 MHz ISM and legacy cellular. Both offer −87 dBc/Hz phase noise at 900 MHz, but ADF4111BRUZ-RL achieves this at higher input frequencies due to improved prescaler and input stage design.