Part A
ADF4356BCPZ
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 2460 個数
- Package
- LFCSP-32
- Series
- クロックタイミング - クロックジェネレータ、PLL、周波数シンセサイザ
Replacement verdict
Compatible functional replacement candidate
The ADF4356BCPZ and ADF4355BCPZ-RL7 are both wideband fractional-N PLL synthesizers from Analog Devices sharing the same 32-lead LFCSP package and 3.15 V to 3.45 V supply range, making them strong functional replacement candidates. The ADF4356BCPZ offers a higher maximum RF output frequency and improved phase noise performance, while the ADF4355BCPZ-RL7 provides comparable core PLL functionality at a lower frequency ceiling. Designers should validate loop filter design, output frequency planning, and register map compatibility before substituting one for the other in an existing design.
Package Type
High match
Supply Voltage Range
High match
Maximum Output Frequency
Validation required
Phase Noise Performance
Validation required
Parts at a glance
Part B
ADF4355BCPZ-RL7
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 2223 個数
- Package
- WFQFN-32
- Series
- クロックタイミング - クロックジェネレータ、PLL、周波数シンセサイザ
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 | ADF4355BCPZ-RL7 | Why it matters |
|---|---|---|---|
| Frequency Range (Max) | 6.8 GHz | 6.8 GHz | Both cover the same upper frequency, so the ADF4356 offers no extended tuning range over the ADF4355 at the top end. |
| Normalized Phase Noise Floor | -227 dBc/Hz | -225 dBc/Hz | A lower normalized phase noise floor yields cleaner spectral performance, which is critical for high-performance synthesizer and LO applications. |
| 1/f Noise (Normalized) | -117 dBc/Hz | -115 dBc/Hz | Lower 1/f noise improves close-in phase noise, affecting signal purity and blocking performance in receiver and transmitter chains. |
| Maximum RF Output Power | 5 dBm | 5 dBm | Output power determines the drive level available to downstream mixers or amplifiers; identical levels mean similar interface requirements. |
| Supply Voltage | 3.0 V to 3.6 V | 3.0 V to 3.6 V | Matching supply ranges allow the parts to be used in the same power rail design without regulator changes. |
| Package / Pin Count | 32-Lead LFCSP (5x5 mm) | 32-Lead LFCSP (5x5 mm) | Identical package and pinout enable drop-in board replacement without layout changes. |
| Integrated VCO | Yes | Yes | Both integrate a VCO, reducing external component count and board area for the synthesizer loop. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Same industrial temperature range means equivalent environmental qualification for most applications. |
| RF Output Divider Range | 1 to 64 | 1 to 64 | Identical divider range provides the same flexibility in generating lower output frequencies from the VCO. |
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 | ADF4356BCPZ | 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 | Clock | Clock |
| Output | Clock | Clock |
| Number of Circuits | 1 | 1 |
| Ratio - Input: Output | 1:2 | 1:2 |
| Differential - Input: Output | Yes/No | Yes/Yes |
| Frequency - Max | 6.8GHz | 6.8GHz |
| Divider / Multiplier | Yes/Yes | Yes/Yes |
| Voltage - Supply | 3.15V ~ 3.45V | 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 ADF4356BCPZ and the ADF4355BCPZ-RL7?
The ADF4356BCPZ and ADF4355BCPZ-RL7 are both fractional-N PLL synthesizers with integrated VCOs from Analog Devices. The ADF4356 offers a higher maximum RF output frequency (6.8 GHz vs 6.8 GHz for the ADF4355, though the ADF4356 provides improved phase noise and higher PFD frequency up to 125 MHz), while the ADF4355BCPZ-RL7 is supplied in tape-and-reel packaging (RL7 suffix) versus the ADF4356BCPZ tray format. Both share a 32-lead LFCSP package and similar pinout, but firmware and register maps differ slightly and must be validated per datasheet.
Are the ADF4356BCPZ and ADF4355BCPZ-RL7 pin-compatible?
Both devices are offered in a 32-lead LFCSP (5 mm × 5 mm) package with a comparable pin assignment per their respective Analog Devices datasheets. However, designers must confirm the exact pin functions and register configuration against each datasheet before considering a layout-compatible substitution, as internal block differences exist.
What is the maximum RF output frequency of each device?
Per Analog Devices datasheets, the ADF4356 provides RF output up to 6.8 GHz, and the ADF4355 also provides RF output up to 6.8 GHz. Both integrate a fundamental VCO covering the wideband range and support divided outputs for lower frequencies.
How do the phase noise and PFD specifications compare?
The ADF4356 is specified with a normalized phase noise floor of approximately −230 dBc/Hz and supports a maximum phase frequency detector (PFD) frequency of 125 MHz. The ADF4355 datasheet specifies a normalized phase noise floor of approximately −227 dBc/Hz with a maximum PFD frequency of 125 MHz. Designers should consult the latest datasheet revisions for exact test conditions.
What does the RL7 suffix on ADF4355BCPZ-RL7 indicate?
The RL7 suffix denotes tape-and-reel packaging (7-inch reel) as defined by Analog Devices ordering conventions. The ADF4356BCPZ is typically supplied in trays. The base part, package (32-lead LFCSP), and temperature grade are otherwise equivalent within each ordering code.
Can the ADF4356BCPZ directly replace the ADF4355BCPZ-RL7 in an existing design?
Direct replacement requires validation of register map differences, loop filter component values, charge pump settings, and output divider configuration against both datasheets. While package and pinout are similar, the devices are not drop-in identical, and firmware must be reviewed before substitution.
What supply voltage and current consumption do these synthesizers require?
Both devices operate from a nominal 3.3 V analog and digital supply (with a separate 5 V charge pump supply option per datasheet). Typical current consumption is on the order of 100 mA to 130 mA depending on configuration; exact values should be taken from the respective Analog Devices datasheet electrical characteristics tables.