Part A
ADF4158CCPZ
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 1970 PCS
- Package
- WFQFN-24
- Series
- Horloge Timing - générateur d'horloge, PLL, synthétiseur de fréquence
Replacement verdict
Not a drop-in replacement
The ADF4158CCPZ and ADF4154BCP are both fractional-N PLL synthesizers, but they differ in maximum operating frequency, reference input frequency, and package footprint, so the ADF4158CCPZ cannot be used as a direct drop-in substitute for the ADF4154BCP without design and layout changes.
Different maximum frequency
Different reference input frequency
Different package footprint
Different supply voltage range
Parts at a glance
Part B
ADF4154BCP
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 5698 PCS
- Package
- WFQFN-20
- Series
- Horloge Timing - générateur d'horloge, PLL, synthétiseur de fréquence
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADF4158CCPZ | ADF4154BCP | Why it matters |
|---|---|---|---|
| Function Type | Fractional-N frequency synthesizer with integrated VCO and waveform generation | Fractional-N frequency synthesizer with integrated VCO | The ADF4158 adds ramp/waveform generation capability, so it is not a drop-in replacement where only basic PLL synthesis is needed. |
| Maximum RF Output Frequency | 6.1 GHz | 4.0 GHz | Higher output frequency range allows the ADF4158 to cover applications the ADF4154 cannot reach. |
| Maximum PFD Frequency | 32 MHz | 32 MHz | Phase frequency detector rate affects phase noise and loop filter design; both parts share the same limit here. |
| Modulus (Fractional Resolution) | 25-bit | 25-bit | Fractional modulus determines frequency resolution; identical resolution supports similar channel spacing. |
| Supply Voltage Range | 2.7 V to 3.3 V | 2.7 V to 3.3 V | Matching supply ranges means both parts can operate from the same rail in a given design. |
| Package | 24-lead LFCSP (4 mm x 4 mm) | 20-lead LFCSP (4 mm x 4 mm) | Different pin counts and footprints prevent direct board-level substitution without layout changes. |
| Waveform/Ramp Generation | Yes (frequency ramp and modulation) | No | Ramp generation is essential for FMCW radar and swept-frequency applications; the ADF4154 lacks this feature. |
| Phase Noise (Normalized) | -220 dBc/Hz (typical normalized) | -216 dBc/Hz (typical normalized) | Lower normalized phase noise improves spectral purity and system sensitivity in RF designs. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature ratings mean both parts suit the same environmental conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADF4158CCPZ | ADF4154BCP |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Type | Fractional N Synthesizer (RF) | Fractional N Synthesizer (RF) |
| PLL | Yes | Yes |
| Input | CMOS, TTL | CMOS |
| Output | Clock | Clock |
| Ratio - Input: Output | 2:1 | 2:1 |
| Differential - Input: Output | Yes/No | Yes/No |
| Frequency - Max | 6.1GHz | 4GHz |
| Divider / Multiplier | Yes/Yes | No/Yes |
| Voltage - Supply | 2.7V ~ 3.3V | 2.7V ~ 3.3V |
| Mounting Type | Surface Mount | Surface Mount |
| Number of Circuits | 1 | - |
| Operating Temperature | -40°C ~ 125°C | - |
Frequently asked questions
What are the key differences between the ADF4158CCPZ and the ADF4154BCP?
The ADF4158CCPZ is a 6.1 GHz fractional-N frequency synthesizer with integrated waveform generation (ramp/FSK/PSK modulation) capability, while the ADF4154BCP is a 4 GHz fractional-N frequency synthesizer without integrated modulation waveform generation. The ADF4158CCPZ supports a higher maximum RF input frequency and includes dedicated ramp generation circuitry, whereas the ADF4154BCP is a simpler fractional-N PLL synthesizer intended for general-purpose frequency synthesis.
Are the ADF4158CCPZ and ADF4154BCP pin-compatible or package-compatible?
No. The ADF4158CCPZ is supplied in a 24-lead LFCSP package, while the ADF4154BCP is supplied in a 20-lead LFCSP package. The different package sizes and pin counts mean the two devices are not drop-in replacements and require different PCB land patterns.
What is the maximum RF input frequency for each device?
The ADF4158CCPZ operates with an RF input frequency up to 6.1 GHz. The ADF4154BCP operates with an RF input frequency up to 4 GHz. Designs requiring operation above 4 GHz must use the ADF4158CCPZ or another synthesizer rated for the target frequency.
Does the ADF4158CCPZ support modulation waveform generation that the ADF4154BCP does not?
Yes. The ADF4158CCPZ integrates ramp generation circuitry supporting frequency ramp (sawtooth and triangular), FSK, and PSK modulation, making it suitable for radar and other modulated-signal applications. The ADF4154BCP does not include this integrated waveform generation capability and is intended for conventional fractional-N frequency synthesis.
What is the operating supply voltage range for these synthesizers?
Both the ADF4158CCPZ and the ADF4154BCP operate from a supply voltage range of 2.7 V to 3.3 V, with a nominal supply of 3.0 V. The digital interface and charge pump performance specifications are defined over this supply range per the respective manufacturer datasheets.
Can the ADF4154BCP be used as a lower-cost alternative to the ADF4158CCPZ?
Only if the application does not require RF operation above 4 GHz or integrated ramp/FSK/PSK modulation. The ADF4154BCP offers a lower maximum RF frequency and lacks the waveform generation block, so it cannot fulfill the modulated-waveform or higher-frequency functions of the ADF4158CCPZ. Substitution must be validated against the specific design requirements and manufacturer documentation.
What type of phase detector and charge pump do these devices use?
Both devices use a digital phase frequency detector (PFD) with a programmable charge pump. The ADF4158CCPZ and ADF4154BCP both provide programmable charge pump current settings, allowing loop filter design flexibility. Designers should consult the respective datasheets for the exact programmable current ranges and PFD maximum frequency specifications.