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 ADF4356BCPZ is a higher-performance successor to the ADF4350BCPZ, sharing the same 32-lead LFCSP footprint and fractional-N PLL synthesizer architecture with integrated VCO. While both devices are functionally comparable for frequency synthesis applications, the ADF4356BCPZ offers an extended frequency range up to 6.8 GHz and improved phase noise performance, making it a viable upgrade path where the ADF4350BCPZ's 4.4 GHz upper limit is insufficient. Designers should validate loop filter component values and register map differences before direct substitution.
Package and Pinout
High match
Frequency Range
Validation required
Supply Voltage
High match
Register Map Compatibility
Validation required
Parts at a glance
Part B
ADF4356BCPZ
아날로그 디바이스(주)
- Lifecycle
- Active
- Stock
- 2460 PCS
- Package
- LFCSP-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 | ADF4356BCPZ | ADF4350BCPZ | Why it matters |
|---|---|---|---|
| Frequency Range (Max) | 6.8 GHz | 4.4 GHz | Determines the highest output frequency the synthesizer can generate; the ADF4356 covers a wider upper band, enabling higher-frequency applications. |
| Frequency Range (Min) | 53.125 MHz | 137.5 MHz | Defines the lowest usable output frequency; the ADF4356 can reach lower frequencies, useful for wider-band designs. |
| Normalized Phase Noise Floor | -227 dBc/Hz | -216 dBc/Hz | Lower phase noise floor yields cleaner spectral performance, critical for high-performance RF and communication systems. |
| Max RF Output Power | +5 dBm | +5 dBm (typical, varies by band) | Output power affects drive capability and link budget; both provide similar output levels but the ADF4356 offers more consistent performance across its wider band. |
| Supply Voltage | 3.15 V to 3.45 V | 3.0 V to 3.6 V | Operating voltage range affects power supply design and compatibility; the ADF4350 tolerates a slightly wider supply range. |
| Package | 32-Lead LFCSP (5 mm x 5 mm) | 32-Lead LFCSP (5 mm x 5 mm) | Package footprint and pinout determine PCB layout compatibility; identical packages ease board-level substitution. |
| Integrated VCO | Yes | Yes | An integrated VCO reduces external component count and board space; both devices include one, simplifying design. |
| Fractional-N Modulus | 25-bit | 12-bit | Higher fractional modulus enables finer frequency resolution and lower spurious levels; the ADF4356 offers significantly better resolution. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Temperature range defines environmental robustness; both parts share the same industrial-grade range. |
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 | ADF4356BCPZ |
|---|---|---|
| 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/No |
| 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 is the fundamental difference between the ADF4356BCPZ and the ADF4350BCPZ?
The ADF4356BCPZ is a higher-performance fractional-N/integer-N PLL synthesizer with an integrated VCO covering 53.125 MHz to 6.8 GHz, while the ADF4350BCPZ covers 137.5 MHz to 4.4 GHz. The ADF4356 offers wider frequency coverage, lower normalized phase noise floor, and higher maximum PFD frequency compared with the ADF4350.
Are the ADF4356BCPZ and ADF4350BCPZ pin-compatible?
No. Both devices are supplied in a 32-lead LFCSP package, but the pin assignments and internal register maps differ. The ADF4356 uses a different register structure and control interface behavior than the ADF4350, so they are not drop-in replacements and require separate PCB layouts and firmware.
What are the output frequency ranges of each device?
The ADF4356BCPZ integrated VCO operates from 3.4 GHz to 6.8 GHz with programmable divide-by-1/2/4/8/16/32/64 output stages, yielding an output range of approximately 53.125 MHz to 6.8 GHz. The ADF4350BCPZ integrated VCO operates from 2.2 GHz to 4.4 GHz with divide-by-1/2/4/8/16 stages, giving an output range of approximately 137.5 MHz to 4.4 GHz.
How do the phase noise specifications compare?
The ADF4356BCPZ specifies a normalized phase noise floor of approximately −227 dBc/Hz (fractional-N) and −229 dBc/Hz (integer-N), while the ADF4350BCPZ specifies approximately −216 dBc/Hz (fractional-N) and −219 dBc/Hz (integer-N). The ADF4356 therefore provides lower phase noise and better jitter performance for demanding applications.
What is the maximum phase frequency detector (PFD) frequency for each part?
The ADF4356BCPZ supports a maximum PFD frequency of 125 MHz, whereas the ADF4350BCPZ supports a maximum PFD frequency of 32 MHz. The higher PFD rate of the ADF4356 enables wider loop bandwidths and lower in-band phase noise.
Do both devices support fractional-N and integer-N operation?
Yes. Both the ADF4356BCPZ and ADF4350BCPZ are fractional-N/integer-N PLL synthesizers with integrated VCOs, supporting both modes of operation via register configuration. The ADF4356 additionally offers a higher resolution fractional modulus and improved spurious performance.
What supply voltage and current consumption do these devices require?
Both devices operate from a nominal 3.3 V analog and digital supply (with a charge pump supply up to 5 V). The ADF4356BCPZ typically draws approximately 75 mA from the 3.3 V supply, while the ADF4350BCPZ typically draws approximately 75 mA as well, though exact values depend on configuration and should be confirmed in the respective datasheets.
Can the ADF4350BCPZ be replaced by the ADF4356BCPZ in an existing design?
Not directly. Although both are 32-lead LFCSP devices, the ADF4356BCPZ has different pin functions, register maps, PFD limits, and VCO range. A replacement requires PCB redesign, firmware/register sequence changes, and revalidation of loop filter and output matching networks against the ADF4356 datasheet.