Part A
ADF4350BCPZ
아날로그 디바이스(주)
- Lifecycle
- Active
- Stock
- 1202 PCS
- Package
- LFCSP-32
- Series
- 클럭 타이밍 - 클럭 발생기, PLL, 주파수 합성기
Replacement verdict
Compatible functional replacement candidate
The ADF4355BCPZ-RL7 is a higher-performance successor to the ADF4350BCPZ, offering an extended frequency range up to 6.8 GHz and improved phase noise, while maintaining the same 32-lead LFCSP footprint and 3.0 V to 3.6 V supply range. Both are integer-N/fractional-N PLL synthesizers with integrated VCOs and share a compatible SPI control interface, making the ADF4355 a viable functional upgrade candidate. However, the register map and programming sequence differ between the two devices, so firmware and loop filter redesign are required before substitution.
Frequency Range
Validation required
Package Type
High match
Supply Voltage
High match
Control Interface
Validation required
Parts at a glance
Part B
ADF4355BCPZ-RL7
아날로그 디바이스(주)
- Lifecycle
- Active
- Stock
- 2223 PCS
- Package
- WFQFN-32
- Series
- 클럭 타이밍 - 클럭 발생기, PLL, 주파수 합성기
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADF4350BCPZ | ADF4355BCPZ-RL7 | Why it matters |
|---|---|---|---|
| Frequency Range (Max) | 4.4 GHz | 6.8 GHz | The upper tuning range determines the highest output frequency the PLL/synthesizer can generate, affecting which applications the part can serve. |
| Normalized Phase Noise Floor | -216 dBc/Hz | -227 dBc/Hz | A lower phase noise floor yields cleaner spectral output, which is critical for high-performance RF and communication systems. |
| Maximum RF Output Power | 5 dBm | 7 dBm | Output power affects the ability to drive downstream stages and the required external amplification in the signal chain. |
| Supply Voltage (Typical) | 3.3 V | 3.3 V (analog/digital), 5 V (charge pump/VCO) | Different supply rail requirements affect board power design and whether the part is a drop-in replacement in an existing design. |
| Package | 32-Lead LFCSP (5x5 mm) | 32-Lead LFCSP (5x5 mm) | Package footprint and pinout determine physical compatibility and whether PCB layout changes are needed for substitution. |
| Integrated VCO | Yes | Yes | An integrated VCO simplifies design and reduces external component count, but the VCO tuning range differs between the two parts. |
| Maximum PFD Frequency | 32 MHz | 125 MHz | A higher phase-frequency detector rate enables wider loop bandwidth and faster lock times, improving synthesizer performance. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | The temperature range defines the environments in which the device can reliably operate, affecting suitability for industrial or outdoor use. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADF4350BCPZ | ADF4355BCPZ-RL7 |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Part Status | Active | Active |
| Type | Fanout Distribution, Fractional N, Integer N, Clock/Frequency Synthesizer (RF) | Fanout Distribution, Fractional N, Integer N, Clock/Frequency Synthesizer (RF) |
| PLL | Yes | Yes |
| Input | CMOS, TTL | Clock |
| Output | Clock | Clock |
| Number of Circuits | 1 | 1 |
| Ratio - Input: Output | 1:2 | 1:2 |
| Differential - Input: Output | No/No | Yes/Yes |
| Frequency - Max | 4.4GHz | 6.8GHz |
| Divider / Multiplier | Yes/Yes | Yes/Yes |
| Voltage - Supply | 3V ~ 3.6V | 3.15V ~ 3.45V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the key differences between the ADF4350BCPZ and ADF4355BCPZ-RL7?
The ADF4350BCPZ is a fractional-N/integer-N PLL synthesizer with an integrated VCO covering 137.5 MHz to 4400 MHz, while the ADF4355BCPZ-RL7 is a newer fractional-N/integer-N PLL synthesizer with an integrated VCO covering 54 MHz to 6800 MHz. The ADF4355 offers wider frequency coverage, lower normalized phase noise floor, and higher maximum PFD frequency compared to the ADF4350.
Are the ADF4350BCPZ and ADF4355BCPZ-RL7 pin-compatible?
No. Both devices are housed in a 32-lead LFCSP package, but the pin functions and register maps differ. The ADF4355 introduces additional features and a different register structure, so they are not pin-compatible and cannot be dropped into the same PCB layout without redesign.
What is the frequency range of each device?
The ADF4350BCPZ integrated VCO operates from 137.5 MHz to 4400 MHz. The ADF4355BCPZ-RL7 integrated VCO operates from 54 MHz to 6800 MHz, providing wider octave coverage for higher-frequency applications.
How do the phase noise specifications compare?
The ADF4355BCPZ-RL7 specifies a lower normalized phase noise floor (approximately −230 dBc/Hz) than the ADF4350BCPZ (approximately −216 dBc/Hz), making the ADF4355 preferable for applications requiring lower phase noise and better spectral purity.
What are the maximum phase frequency detector (PFD) frequencies?
The ADF4350BCPZ supports a maximum PFD frequency of 32 MHz. The ADF4355BCPZ-RL7 supports a higher maximum PFD frequency of 100 MHz, enabling wider loop bandwidths and faster lock times.
What supply voltage and current consumption do these devices require?
Both devices operate from a 3.0 V to 3.6 V analog and digital supply, with a charge pump supply of up to 5.5 V. The ADF4355BCPZ-RL7 typically draws approximately 75 mA from the 3.3 V supply, while the ADF4350BCPZ draws approximately 70 mA, depending on configuration.
Can the ADF4355BCPZ-RL7 directly replace the ADF4350BCPZ in an existing design?
No. Although both are 32-lead LFCSP fractional-N synthesizers, differences in pin functions, register maps, frequency range, PFD limits, and loop filter requirements mean the ADF4355 cannot be used as a drop-in replacement. The design must be revalidated against the ADF4355 datasheet.
What is the meaning of the -RL7 suffix on the ADF4355BCPZ-RL7?
The -RL7 suffix indicates tape-and-reel packaging with a reel quantity of 750 pieces, as specified in the Analog Devices ordering guide. The ADF4350BCPZ is supplied in a standard tray or tube packaging unless a reel suffix is specified.