Part A
ADF4156BCPZ
ADI公司
- Lifecycle
- Active
- Stock
- 1350 件
- Package
- WFQFN-20
- Series
- 時鐘定時-時鐘發生器、PLL、頻率合成器
Replacement verdict
Not a drop-in replacement
The ADF4156BCPZ and ADF4111BCP are both fractional-N PLL frequency synthesizers, but they differ in maximum operating frequency, supply voltage range, and package footprint, so the ADF4111BCP cannot serve as a direct drop-in substitute for the ADF4156BCPZ without design validation.
Different maximum frequency
Different supply voltage range
Different package footprint
Different phase noise performance
Parts at a glance
Part B
ADF4111BCP
ADI公司
- Lifecycle
- Active
- Stock
- 9249 件
- Package
- WFQFN-20
- Series
- 時鐘定時-時鐘發生器、PLL、頻率合成器
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADF4156BCPZ | ADF4111BCP | Why it matters |
|---|---|---|---|
| Maximum RF Input Frequency | 6 GHz | 4 GHz | Determines the highest frequency the PLL synthesizer can operate at; the ADF4156 supports higher-frequency applications. |
| Number of Programmable Modulus Bits (Fractional) | 25-bit fixed modulus | Not fractional (integer-N only) | Fractional-N capability enables finer frequency resolution and lower phase noise; the ADF4156 is fractional-N while the ADF4111 is integer-N. |
| Synthesizer Type | Fractional-N | Integer-N | Architecture affects resolution, phase noise, and loop filter design; these are not functionally interchangeable in fractional applications. |
| Supply Voltage Range | 2.7 V to 3.3 V | 2.7 V to 5.5 V | The ADF4111 tolerates a wider supply range, allowing 5 V operation, while the ADF4156 is limited to 3.3 V systems. |
| Package Type | 20-Lead LFCSP | 20-Lead TSSOP | Different footprints and thermal characteristics affect PCB layout and drop-in substitutability. |
| Normalized Phase Noise Floor | -216 dBc/Hz (typical) | -212 dBc/Hz (typical) | Lower phase noise floor improves spectral purity of the synthesized signal, important for sensitive RF systems. |
| Maximum PFD Frequency | 32 MHz | 55 MHz | Higher phase-frequency detector rate can reduce phase noise and allow wider loop bandwidths; the ADF4111 supports a higher PFD rate. |
| Charge Pump Current (Programmable) | 0.3 mA to 5 mA | 0.625 mA to 5 mA | Charge pump current range affects loop filter design and lock time; differing minimum currents require loop filter recalculation. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Both share the same industrial temperature range, so thermal environment is not a differentiator. |
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Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADF4156BCPZ | ADF4111BCP |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Type | Fractional N Synthesizer (RF) | Clock/Frequency Synthesizer (RF) |
| PLL | Yes | Yes |
| Input | CMOS, TTL | Clock |
| Output | Clock | Clock |
| Ratio - Input: Output | 2:1 | 2:1 |
| Differential - Input: Output | Yes/No | Yes/No |
| Frequency - Max | 6.2GHz | 1.2GHz |
| Divider / Multiplier | Yes/Yes | Yes/No |
| Voltage - Supply | 2.7V ~ 3.3V | 2.7V ~ 5.5V |
| Mounting Type | Surface Mount | Surface Mount |
| Number of Circuits | 1 | - |
| Operating Temperature | -40°C ~ 85°C | - |
Frequently asked questions
What are the key differences between the ADF4156BCPZ and the ADF4111BCP?
The ADF4156BCPZ is a 6.2 GHz fractional-N PLL synthesizer with an integrated VCO divider range and a maximum RF input of 6.2 GHz, while the ADF4111BCP is a 1.2 GHz integer-N PLL synthesizer. The ADF4156BCPZ supports fractional-N operation with a 25-bit fixed modulus, whereas the ADF4111BCP is integer-N only. Both are housed in 20-lead LFCSP packages but differ in frequency range, synthesis architecture, and phase detector frequency capabilities.
Are the ADF4156BCPZ and ADF4111BCP pin-compatible?
No. Although both devices are offered in 20-lead LFCSP packages, their pin functions and internal architectures differ. The ADF4156BCPZ includes fractional-N related pins and a different register map compared to the ADF4111BCP integer-N architecture. A direct PCB drop-in replacement is not supported without schematic and layout changes.
What is the maximum RF input frequency for each device?
The ADF4156BCPZ supports RF input frequencies up to 6.2 GHz. The ADF4111BCP supports RF input frequencies up to 1.2 GHz. Designs requiring operation above 1.2 GHz cannot use the ADF4111BCP and must use a higher-frequency device such as the ADF4156BCPZ.
Do both devices support fractional-N synthesis?
No. The ADF4156BCPZ is a fractional-N frequency synthesizer supporting fractional-N operation with a 25-bit fixed modulus. The ADF4111BCP is an integer-N frequency synthesizer and does not support fractional-N operation. This architectural difference affects phase noise, spurious performance, and loop filter design.
What are the power supply requirements for the ADF4156BCPZ and ADF4111BCP?
Both devices operate from a nominal 3.0 V to 3.6 V supply. The ADF4156BCPZ typically draws approximately 20 mA to 25 mA depending on configuration, while the ADF4111BCP draws approximately 4.5 mA to 7 mA. Designers should verify exact current consumption against the respective manufacturer datasheets for the target operating conditions.
Can the ADF4111BCP be used as a drop-in replacement for the ADF4156BCPZ in an existing design?
No. The ADF4111BCP has a lower maximum RF input frequency (1.2 GHz vs 6.2 GHz), lacks fractional-N capability, and has a different register map and pin configuration. Replacing the ADF4156BCPZ with the ADF4111BCP would require redesign of the RF front end, loop filter, and firmware, and is only viable if the target frequency is below 1.2 GHz and integer-N operation is acceptable.
What phase detector frequency do these devices support?
The ADF4156BCPZ supports a phase detector frequency up to 32 MHz. The ADF4111BCP supports a phase detector frequency up to 55 MHz. These limits should be observed when designing the loop filter and reference path for each device.
Which device is better suited for high-frequency applications?
The ADF4156BCPZ is better suited for high-frequency applications because its RF input operates up to 6.2 GHz, whereas the ADF4111BCP is limited to 1.2 GHz. For applications above 1.2 GHz, the ADF4156BCPZ is the appropriate choice within this comparison.