Part A
ADF4351BCPZ
아날로그 디바이스(주)
- Lifecycle
- Active
- Stock
- 2243 PCS
- Package
- VFQFN-32
- Series
- 클럭 타이밍 - 클럭 발생기, PLL, 주파수 합성기
Replacement verdict
Compatible functional replacement candidate
The ADF4351BCPZ is a compatible functional replacement candidate for the ADF4350BCPZ-RL7, sharing the same 5x5 mm LFCSP package, 3.0 V to 3.6 V supply range, and 32-lead pinout, while extending the upper frequency range to 4400 MHz. Designers should validate the wider loop filter and VCO calibration behavior at the band edges before committing to production, but the two synthesizers are largely interchangeable in existing PLL designs.
Package Type
High match
Supply Voltage Range
High match
Output Frequency Range
Validation required
Phase Noise and PLL Architecture
Validation required
Parts at a glance
Part B
ADF4350BCPZ-RL7
아날로그 디바이스(주)
- Lifecycle
- Active
- Stock
- 4320 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-RL7 | ADF4351BCPZ | Why it matters |
|---|---|---|---|
| Frequency Range (Max) | 4.4 GHz | 4.4 GHz | Both cover the same upper tuning range, so maximum output frequency capability is equivalent. |
| Frequency Range (Min) | 137.5 MHz | 35 MHz | The ADF4351 extends to a much lower minimum frequency, enabling lower-band applications the ADF4350 cannot reach directly. |
| Normalized Phase Noise Floor | -216 dBc/Hz | -221 dBc/Hz | Lower phase noise floor improves spectral purity and is critical for sensitive RF and communication systems. |
| Max RF Output Power | 5 dBm | 5 dBm | Identical output power means similar drive capability into downstream stages. |
| Supply Voltage Range | 3.0 V to 3.6 V | 3.0 V to 3.6 V | Same supply requirements allow drop-in compatibility with existing power designs. |
| Package / Pin Count | 32-Lead LFCSP | 32-Lead LFCSP | Identical package and pinout support direct board-level substitution. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Matching temperature ratings ensure equivalent environmental robustness. |
| Integrated VCO | Yes | Yes | Both integrate a VCO, simplifying design and reducing external component count. |
| Programmable Modulus | 12-bit | 12-bit | Same fractional modulus resolution supports comparable frequency synthesis flexibility. |
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 | ADF4351BCPZ | ADF4350BCPZ-RL7 |
|---|---|---|
| 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 | CMOS, TTL |
| Output | Clock | Clock |
| Number of Circuits | 1 | 1 |
| Ratio - Input: Output | 1:2 | 1:2 |
| Differential - Input: Output | No/Yes | No/No |
| Frequency - Max | 4.4GHz | 4.4GHz |
| Divider / Multiplier | Yes/Yes | Yes/Yes |
| Voltage - Supply | 3V ~ 3.6V | 3V ~ 3.6V |
| 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-RL7 and the ADF4351BCPZ?
Both are fractional-N PLL frequency synthesizers with integrated VCOs from Analog Devices in a 32-lead LFCSP package. The ADF4351BCPZ extends the upper RF output frequency to 4400 MHz, whereas the ADF4350BCPZ-RL7 covers up to 4400 MHz as well but is specified with a maximum RF output of 4400 MHz; the ADF4351 offers improved phase noise and a higher maximum PFD frequency of 32 MHz versus 25 MHz on the ADF4350. The ADF4350BCPZ-RL7 is supplied in tape-and-reel packaging (RL7 suffix), while the ADF4351BCPZ is typically supplied in trays.
Are the ADF4350BCPZ-RL7 and ADF4351BCPZ pin-compatible?
Yes. Both devices are offered in the same 32-lead LFCSP (5 mm × 5 mm) package with the same pinout, allowing a common PCB footprint. However, firmware and register settings should be reviewed because the ADF4351 supports a higher maximum PFD frequency and different VCO band-divider settings.
What is the output frequency range of each device?
The ADF4350BCPZ-RL7 provides a fundamental output range of 137.5 MHz to 4400 MHz using its integrated VCO and programmable dividers. The ADF4351BCPZ provides a fundamental output range of 35 MHz to 4400 MHz, with the lower extension achieved through the VCO divider settings.
How do the phase noise specifications compare?
The ADF4351BCPZ is specified with a normalized phase noise floor of −220 dBc/Hz (typical) in fractional-N mode, while the ADF4350BCPZ-RL7 is specified at −216 dBc/Hz (typical). In integer-N mode, the ADF4351 achieves −223 dBc/Hz versus −219 dBc/Hz for the ADF4350, giving the ADF4351 a phase-noise advantage in sensitive applications.
What is the maximum phase frequency detector (PFD) frequency for each part?
The ADF4350BCPZ-RL7 supports a maximum PFD frequency of 25 MHz. The ADF4351BCPZ supports a maximum PFD frequency of 32 MHz, which allows a higher reference comparison rate and can reduce fractional spurs in some designs.
Do both devices support the same supply voltage and current consumption?
Both 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. Typical current consumption is approximately 75 mA for the ADF4350BCPZ-RL7 and approximately 75 mA for the ADF4351BCPZ, with the ADF4351 offering a programmable power-down mode that reduces current to typically 10 µA.
Can the ADF4351BCPZ be used as a drop-in replacement for the ADF4350BCPZ-RL7?
Because the package and pinout are identical, the ADF4351BCPZ can be placed on the same footprint. However, it is not a firmware-transparent drop-in replacement: register maps, VCO band selection, and PFD limits differ, so the control software must be updated and the design revalidated against the ADF4351 datasheet before substitution.
What are the packaging differences between the ADF4350BCPZ-RL7 and ADF4351BCPZ?
The ADF4350BCPZ-RL7 suffix indicates tape-and-reel packaging (7-inch reel) suitable for automated assembly. The ADF4351BCPZ is supplied in standard tray packaging. Both use the same 32-lead LFCSP (CP-32-2) package and are RoHS-compliant.