ADF4218BRU - 2.5GHz Dual RF PLL Synthesizer | Analog Devices
料号： ADF4218BRU ✓ 量产中ADF4218BRU 概述
A phase-locked loop, or PLL, is a feedback-controlled timing circuit that locks an output oscillator to a stable reference frequency. The oscillator and voltage-controlled oscillator form the complete frequency synthesizer, while the ADF4218BRU handles reference division, phase detection, charge-pump current generation, programmable integer-N division, and prescaling. In the wider semiconductor hierarchy, it is a clock-and-timing IC and frequency synthesizer used for RF signal generation and frequency conversion.
The device supports RF prescaler choices of 16/17 or 64/65 and selectable charge-pump currents. Its three-wire serial interface allows reference frequency, prescaler, integer-N counter, charge-pump, and band-select programming. Available dual-synthesizer configurations include 550 MHz/1.2 GHz, 550 MHz/2.0 GHz, and 550 MHz/2.5 GHz, depending on the selected variant and operating setup.
Each synthesizer path uses a digital phase-frequency detector to compare a divided feedback signal with the divided reference. The resulting phase error drives the charge pump and external loop filter, which in turn control a VCO. Designers select loop bandwidth, reference division, charge-pump current, and filter components to balance phase noise, lock time, spur performance, and reference-multiplier requirements.
Typical uses include wireless handset RF and IF local oscillators, GSM receivers and transmitters, wireless infrastructure, instrumentation, and other RF up-conversion or down-conversion systems. The 20-pin TSSOP package is also suitable for compact, surface-mounted frequency-generation boards where the external VCO and loop filter can be placed close to the RF signal path.
When designing around the ADF4218BRU, preserve the datasheet-specified decoupling and keep the reference, loop-filter, and VCO connections compact. The integrated divider and detector simplify frequency planning, but phase noise, lock range, and spur performance still depend heavily on the external VCO, loop filter, reference quality, and board layout.
This page combines verified manufacturer and distributor information with practical PLL design considerations, source-backed alternatives, and a parameter comparison. It highlights where the ADF4218BRU fits and where ADF4216BRU, ADF4217BRU, or the web-referenced ADF4212LBRUZ-RL may require further qualification before substitution.
直接替换替代料： ADF4218BRU ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： ADF4218BRU （相同外形与封装尺寸） ——差异在于 Package, Power-Down Mode, Serial Interface.
ADF4216BRU
✅ 直接替换 ⚠️ 规格未核验联系询价
查看数据手册 →ADF4217BRU
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
ADF4212LBRUZ-RL
✅ 直接替换📋 参考替代料（不在目录中）
ADF4218BRU 规格参数
| Product Type | Dual integer-N RF PLL frequency synthesizer |
| Number of Synthesizers | 2 |
| Maximum RF Input Frequency | 2.5 GHz |
| Frequency Configuration Options | 550 MHz/1.2 GHz, 550 MHz/2.0 GHz, or 550 MHz/2.5 GHz |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Maximum Supply Voltage | 5.5 V |
| 工作温度范围 | -40°C to +85°C |
| Serial Interface | 3-wire |
| RF Prescaler Options | 16/17 or 64/65 |
| Charge Pump | Precision charge pump with selectable current |
| Phase Detector | Low-noise digital phase-frequency detector |
| Reference Divider | Programmable |
| Integer-N Divider | Programmable |
| Power-Down Mode | Supported |
| 封装 | TSSOP-20 |
| Terminal Count | 20 terminals |
| Terminal Pitch | 0.65 mm |
ADF4218BRU tssop-20 引脚配置指南
ADF4218BRU（tssop-20 封装）的引脚配置。 引脚编号、功能和连接图在制造商数据手册中定义。请参阅该手册以了解确切的封装尺寸和焊接指南。
暂无详细引脚数据： ADF4218BRU.
请参阅 数据手册 以查看完整引脚配置。
典型应用
ADF4218BRU 适用于 6 应用s: Wireless Transmitter Local Oscillator, Wireless Receiver IF Local Oscillator, GSM Radio Equipment, RF Test and Measurement Equipment, RF Up-Conversion and Down-Conversion, RF Communication Modules.
Wireless Transmitter Local Oscillator
The ADF4218BRU fits wireless transmitter LO generation because it synthesizes up to 2.5 GHz and supports programmable integer-N division, selectable charge-pump current, and 16/17 or 64/65 RF prescalers. It can pair with an external VCO and loop filter to create a tunable RF output for up-conversion stages. The dual architecture also permits a second synthesis path for an IF-related oscillator. Final suitability depends on phase noise, spur levels, lock time, output power, and reference quality, which are not fully quantified in the supplied data.
推荐
Wireless Receiver IF Local Oscillator
The ADF4218BRU is suitable for receiver down-conversion because the Analog Devices product page identifies both RF and IF local-oscillator generation as core uses. Its low-noise digital phase-frequency detector and programmable reference divider support dual-channel RF/IF synthesis, while the selectable charge-pump current allows loop dynamics to be tuned with the external filter. Actual IF-plan suitability requires the intended IF frequency, reference source, VCO tuning range, and phase-noise mask to be checked against the complete data sheet.
推荐
GSM Radio Equipment
The listed GSM application makes the ADF4218BRU appropriate for classic GSM radio frequency-generation blocks where a low-phase-noise local oscillator is required. Its integer-N architecture supports programmable division from a stable reference, and the dual synthesizer can independently support RF and IF paths. The device should be paired with a VCO whose tuning range and phase-noise performance meet the receiver or transmitter mask. Reference spurs and loop-filter design remain critical because the supplied data does not provide application-specific noise and lock-time targets.
推荐
RF Test and Measurement Equipment
The ADF4218BRU can support programmable local-oscillator generation in RF instrumentation because it combines dual integer-N synthesis paths with a three-wire control interface. A host or embedded controller can configure the reference divider, prescaler, integer-N counter, charge pump, and band selection, enabling repeatable RF sweep points when paired with a suitable VCO. Designers should prioritize low reference phase noise, deterministic register updates, and careful isolation between the synthesizer, loop filter, and output chain.
推荐
RF Up-Conversion and Down-Conversion
The ADF4218BRU is directly applicable to RF frequency-conversion blocks because its two synthesizer sections can supply local-oscillator signals used in up-conversion and down-conversion. The verified manufacturer description specifically identifies these receiver and transmitter functions. The programmable prescaler and integer-N divider provide flexible channel planning, while the external charge pump and loop filter set the loop dynamics. Engineers must confirm phase noise and spur performance at the mixer outputs and provide an output-isolating RF path.
推荐
RF Communication Modules
The ADF4218BRU can be used in compact RF communication modules requiring two coordinated frequency sources within a 20-pin TSSOP footprint. The 0.65 mm terminal pitch supports dense surface-mount layouts, and the 2.7 V to 5.5 V operating range allows integration with common low-voltage supply systems. The device requires an external VCO and loop filter, so its practical footprint depends on those components. Power consumption, reference-divider ratio, lock behavior, and conducted emissions must be evaluated at system level.
推荐
推荐产品汇总
工程参考数据： ADF4218BRU ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | ADF4216BRU | ADF4217BRU | ADF4212LBRUZ-RL |
|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | TSSOP-20 | TSSOP-20 | TSSOP-20 | TSSOP-20 |
| Product Architecture | Dual RF PLL frequency synthesizer | Dual frequency synthesizer | Dual frequency synthesizer | Single clock generator |
关键差异点
- Dedicated dual RF and IF synthesis architecture （对比 ADF4212LBRUZ-RL)
- Direct support for the 550 MHz to 2.5 GHz RF operating range （对比 ADF4212LBRUZ-RL)
- Selectable RF prescaler and charge-pump programming （对比 ADF4212LBRUZ-RL)
设计说明
Place the ADF4218BRU, its decoupling capacitors, and the associated loop-filter components close together and keep sensitive RF and reference routes away from digital programming traces. The ADF4218BRU requires external VCO and loop-filter elements, so their physical placement can dominate performance. Use a continuous ground reference under the TSSOP footprint, verify the terminal assignments in the manufacturer pinout, and keep the loop-filter return path short to reduce coupling between the sensitive charge-pump node and other circuitry.
Treat the reference input and charge-pump connections as high-impedance or high-value analog nodes. The reference signal quality directly influences synthesized phase noise and reference-divider spurs, while the charge-pump and loop-filter nodes are sensitive to leakage, vibration, and nearby switching sources. Route the reference away from digital clocks and dc-dc converters, use a stable low-noise reference, and preserve the component placement and grounding shown in the manufacturer’s reference implementation.
Do not approve a family-member or cross-reference substitution solely from the package name. Check that the selected device has the required RF range, reference-divider capability, prescaler ratio, integer-N range, charge-pump settings, band-selection behavior, register map, and three-wire programming sequence. The ADF4212LBRUZ-RL comparison identifies matching terminals and package, but it also describes a single clock generator rather than the target’s dual RF PLL architecture; therefore, firmware and system requirements must be reviewed before substitution.
合规信息
The supplied verified results do not explicitly state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. No compliance claim has been inferred from the manufacturer association.
