Part A
ADF4156BCPZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 1350 PCS
- Package
- WFQFN-20
- Series
- Clock-Timing - Clock Generators, PLLs, Frequency Synthesizers
Replacement verdict
Compatible functional replacement candidate
The ADF4157BCPZ and ADF4156BCPZ are both fractional-N PLL frequency synthesizers from Analog Devices in the same 20-lead LFCSP package, sharing a common supply range and interface architecture. The ADF4157BCPZ offers a higher maximum RF input frequency and a wider operating temperature range, making it a viable functional replacement candidate for the ADF4156BCPZ in most designs, provided the higher frequency capability and thermal margin are acceptable and the specific loop filter and register configuration are revalidated.
Package Type
High match
Supply Voltage Range
High match
Maximum RF Input Frequency
Validation required
Operating Temperature Range
Validation required
Parts at a glance
Part B
ADF4157BCPZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6114 PCS
- Package
- WFQFN-20
- Series
- Clock-Timing - Clock Generators, PLLs, Frequency Synthesizers
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 | ADF4156BCPZ | Why it matters |
|---|---|---|---|
| Maximum RF Input Frequency | 6 GHz | 6 GHz | Both parts support the same upper frequency limit, so they are interchangeable for high-band applications up to 6 GHz. |
| Maximum PFD Frequency | 32 MHz | 32 MHz | Identical phase frequency detector limit determines the maximum comparison rate and achievable phase noise performance. |
| Fractional Modulus | 2^25 (33,554,432) | 2^25 (33,554,432) | A larger fractional modulus allows finer frequency resolution and lower spurious levels; both share the same resolution capability. |
| RF Bandwidth | Up to 6 GHz | Up to 6 GHz | Defines the operating frequency range of the PLL synthesizer; matching bandwidths confirm functional substitutability. |
| Supply Voltage Range | 2.7 V to 3.3 V | 2.7 V to 3.3 V | Compatible supply requirements mean the same power rail design can be reused without modification. |
| Package Type | 20-Lead LFCSP (4x4 mm) | 20-Lead LFCSP (4x4 mm) | Identical package and footprint allow drop-in replacement on an existing PCB layout. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Same industrial temperature range ensures equivalent environmental robustness for both parts. |
| Charge Pump Current (Programmable) | 0.3 mA to 5 mA | 0.3 mA to 5 mA | Programmable charge pump current affects loop filter design and lock time; matching ranges support equivalent loop dynamics. |
| Interface Type | 3-Wire SPI | 3-Wire SPI | Same serial interface protocol allows the same microcontroller firmware to drive either device. |
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 | ADF4156BCPZ | ADF4157BCPZ |
|---|---|---|
| Part Status | Active | Active |
| Type | Fractional N Synthesizer (RF) | Fractional N Synthesizer (RF) |
| PLL | Yes | Yes |
| Input | CMOS, TTL | CMOS, TTL |
| Output | Clock | Clock |
| Number of Circuits | 1 | 1 |
| Ratio - Input: Output | 2:1 | 2:1 |
| Differential - Input: Output | Yes/No | Yes/No |
| Frequency - Max | 6.2GHz | 6GHz |
| Divider / Multiplier | Yes/Yes | Yes/Yes |
| Voltage - Supply | 2.7V ~ 3.3V | 2.7V ~ 3.3V |
| 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 ADF4157BCPZ and ADF4156BCPZ fractional-N PLL synthesizers?
Both are Analog Devices fractional-N PLL frequency synthesizers in a 20-lead LFCSP package. The ADF4156BCPZ operates from 0.5 GHz to 6.2 GHz with a maximum RF input frequency of 6.2 GHz, while the ADF4157BCPZ operates from 0.5 GHz to 6.0 GHz. The ADF4157BCPZ features a higher maximum phase detector frequency of 32 MHz versus 25 MHz for the ADF4156BCPZ, and the ADF4157BCPZ offers a lower normalized phase noise floor. Both use a 3-wire SPI-compatible interface and operate from a 2.7 V to 3.3 V supply.
Can the ADF4157BCPZ and ADF4156BCPZ be used as drop-in replacements for each other?
They share the same 20-lead LFCSP package and pinout, but they are not identical in performance. The ADF4157BCPZ supports a higher phase detector frequency (32 MHz vs 25 MHz) and different RF bandwidth (6.0 GHz vs 6.2 GHz). A replacement should only be made after verifying loop filter design, charge pump settings, and register configuration against the respective datasheets.
What is the maximum RF input frequency for each device?
The ADF4156BCPZ has a maximum RF input frequency of 6.2 GHz. The ADF4157BCPZ has a maximum RF input frequency of 6.0 GHz. Both have a minimum RF input frequency of 0.5 GHz.
What supply voltage range do the ADF4157BCPZ and ADF4156BCPZ require?
Both devices operate from a single supply of 2.7 V to 3.3 V. The charge pump supply (Vp) can be operated up to 5.5 V on both parts to allow a wider tuning voltage range for the VCO.
What is the maximum phase detector frequency of each device?
The ADF4156BCPZ supports a maximum phase detector frequency of 25 MHz. The ADF4157BCPZ supports a maximum phase detector frequency of 32 MHz, which can allow a higher loop bandwidth and faster lock times when the loop filter is designed accordingly.
Do both devices support fractional-N operation and what modulus range is available?
Yes, both the ADF4157BCPZ and ADF4156BCPZ are fractional-N synthesizers. Both offer a programmable fractional modulus. The ADF4156BCPZ provides a 25-bit fixed modulus, while the ADF4157BCPZ provides a programmable modulus. Designers should confirm the exact modulus and register map in the respective datasheets before configuration.
What package and pin count do the ADF4157BCPZ and ADF4156BCPZ use?
Both devices are supplied in a 20-lead LFCSP (lead frame chip scale package) with exposed pad. The package footprint and pinout are the same, which simplifies PCB layout reuse, but electrical differences between the two parts must still be validated.