Part A
ADF4157BCPZ
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6114 ПКС
- Package
- WFQFN-20
- Series
- Часовое время - Часовые генераторы, PLL, частотные синтезаторы
Replacement verdict
Compatible functional replacement candidate
The ADF4157BCPZ and ADF4112BCP are both fractional-N PLL frequency synthesizers in a 20-lead LFCSP package, making them a viable functional replacement candidate. However, the ADF4157BCPZ offers a higher maximum RF input frequency and a wider operating range, so the system design must be validated against the target frequency plan and loop filter requirements before substitution.
Package Type
High match
Supply Voltage Range
High match
Maximum RF Input Frequency
Validation required
Synthesizer Architecture
Validation required
Parts at a glance
Part B
ADF4112BCP
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6937 ПКС
- Package
- WFQFN-20
- Series
- Часовое время - Часовые генераторы, PLL, частотные синтезаторы
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADF4157BCPZ | ADF4112BCP | Why it matters |
|---|---|---|---|
| Maximum RF Input Frequency | 6 GHz | 3 GHz | Determines the highest frequency the PLL can synthesize; the ADF4157 supports higher-frequency applications. |
| Number of Fractional/Integer Modes | Fractional-N | Integer-N | Fractional-N allows finer frequency resolution and faster settling, while integer-N is simpler but coarser. |
| Maximum PFD Frequency | 32 MHz | 55 MHz | Higher phase-frequency detector rates can reduce phase noise and improve loop bandwidth. |
| Supply Voltage Range | 2.7 V to 3.3 V | 2.7 V to 5.5 V | Affects compatibility with the system power rail; the ADF4112 tolerates a wider supply range. |
| Package Type | 20-Lead LFCSP | 16-Lead LFCSP | Different footprints and pin counts affect PCB layout and drop-in substitutability. |
| Normalized Phase Noise Floor | -216 dBc/Hz | -212 dBc/Hz | Lower phase noise floor yields cleaner synthesized signals, important for sensitive RF systems. |
| Charge Pump Current (Max) | 5 mA | 5 mA | Charge pump current influences loop filter design and lock time; both offer similar maximum drive. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Confirms both parts suit the same industrial temperature environments. |
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 | ADF4157BCPZ | ADF4112BCP |
|---|---|---|
| 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 | 6GHz | 3GHz |
| 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 ADF4157BCPZ and the ADF4112BCP?
The ADF4157BCPZ is a fractional-N PLL frequency synthesizer with an integrated VCO, operating up to 6 GHz, while the ADF4112BCP is an integer-N PLL synthesizer without an integrated VCO, operating up to 3 GHz. The ADF4157BCPZ supports fractional-N operation for finer frequency resolution, whereas the ADF4112BCP uses integer-N architecture.
Are the ADF4157BCPZ and ADF4112BCP pin-compatible?
No. The ADF4157BCPZ is supplied in a 24-lead LFCSP package, while the ADF4112BCP is supplied in a 16-lead TSSOP package. The different package types and pin counts mean they are not pin-compatible and cannot be directly substituted on the same PCB footprint.
What is the maximum operating frequency of each device?
The ADF4157BCPZ supports RF input frequencies up to 6 GHz. The ADF4112BCP supports RF input frequencies up to 3 GHz. The higher frequency capability of the ADF4157BCPZ makes it suitable for higher-band applications.
Do both devices require an external VCO?
No. The ADF4157BCPZ includes an integrated VCO, reducing external component count and board space. The ADF4112BCP does not include an integrated VCO and requires an external VCO to complete the PLL loop.
What is the difference in frequency resolution between the two parts?
The ADF4157BCPZ, as a fractional-N synthesizer, provides finer frequency resolution than the ADF4112BCP, which uses integer-N architecture. Fractional-N operation allows step sizes smaller than the phase detector frequency, which is advantageous for applications requiring fine frequency tuning.
What are the typical applications for each device?
The ADF4157BCPZ is typically used in wireless infrastructure, microwave point-to-point links, and instrumentation requiring high-frequency synthesis with fine resolution. The ADF4112BCP is commonly used in wireless handsets, base stations, and other RF systems where integer-N synthesis up to 3 GHz is sufficient.
What supply voltage do these devices require?
Both the ADF4157BCPZ and the ADF4112BCP operate from a 3.0 V to 3.6 V supply. Designers should verify the exact supply requirements against the respective manufacturer datasheets for the specific operating conditions.