Part A
ADF4157BCPZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6114 PCS
- Package
- WFQFN-20
- Series
- Clock-Timing - Clock Generators, PLLs, Frequency Synthesizers
Replacement verdict
Compatible functional replacement candidate
The ADF4157BCPZ and ADF4113BCP are both fractional-N PLL frequency synthesizers in a 20-lead LFCSP package with a compatible 3-wire SPI interface and overlapping supply voltage ranges, making the ADF4157BCPZ a viable functional replacement candidate for the ADF4113BCP in many designs. However, the two devices differ in maximum operating frequency, phase detector frequency, and fractional modulator resolution, so the replacement must be validated against the target RF band and loop filter design before adoption.
Maximum RF Input Frequency
Validation required
Phase Detector Frequency
Validation required
Package Type
High match
Serial Interface
High match
Parts at a glance
Part B
ADF4113BCP
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2741 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 | ADF4113BCP | Why it matters |
|---|---|---|---|
| Maximum RF Input Frequency | 6 GHz | 4 GHz | Determines the highest frequency the PLL synthesizer can operate at; the ADF4157 supports higher-frequency applications. |
| Maximum PFD Frequency | 32 MHz | 55 MHz | A higher phase frequency detector rate allows wider loop bandwidth and faster lock times; the ADF4113 supports a higher PFD rate. |
| Normalized Phase Noise Floor | -219 dBc/Hz | -211 dBc/Hz | Lower phase noise floor yields cleaner synthesized signals; the ADF4157 offers better noise performance. |
| RF Input Sensitivity Range | -8 dBm to +8 dBm (typical) | -10 dBm to 0 dBm (typical) | Defines the input power window the prescaler can reliably divide; affects required drive level from the VCO. |
| Supply Voltage Range | 2.7 V to 3.3 V | 2.7 V to 3.3 V | Both operate over the same supply range, so power-rail compatibility is maintained. |
| Package | 20-Lead LFCSP (4 mm x 4 mm) | 20-Lead LFCSP (4 mm x 4 mm) | Identical package and footprint allow drop-in board compatibility. |
| Charge Pump Current (Programmable) | Up to 5 mA | Up to 5 mA | Charge pump current sets loop gain and loop filter design; matching ranges simplify loop redesign. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical industrial temperature range supports the same environmental conditions. |
| Modulus / Fractional Capability | Fractional-N (25-bit fixed modulus) | Integer-N | Fractional-N allows finer frequency resolution and lower phase noise for a given PFD; integer-N is simpler but coarser. This is a fundamental architectural difference affecting substitutability. |
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 | ADF4113BCP |
|---|---|---|
| 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 | 4GHz |
| 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 ADF4113BCP?
The ADF4157BCPZ is a fractional-N PLL synthesizer with an integrated VCO, operating up to 6 GHz, while the ADF4113BCP is an integer-N PLL synthesizer without an integrated VCO, operating up to 4 GHz. The ADF4157BCPZ offers fractional-N capability and higher frequency range, whereas the ADF4113BCP is a simpler integer-N solution.
Are the ADF4157BCPZ and ADF4113BCP pin-compatible?
No, they are not pin-compatible. The ADF4157BCPZ is housed in a 24-lead LFCSP package, while the ADF4113BCP is in a 20-lead TSSOP package. The pin counts and functions differ, so they cannot be directly interchanged on the same PCB footprint.
Can the ADF4157BCPZ replace the ADF4113BCP in an existing design?
Direct replacement is not possible due to differences in package, pinout, and architecture (fractional-N vs integer-N). A redesign of the PCB and loop filter, along with firmware changes for register programming, would be required. The ADF4157BCPZ also integrates a VCO, which the ADF4113BCP does not.
What is the maximum operating frequency of each device?
The ADF4157BCPZ supports RF output frequencies up to 6 GHz. The ADF4113BCP supports frequencies up to 4 GHz. These values are specified in the respective manufacturer datasheets.
Do both devices require an external VCO?
No. The ADF4157BCPZ includes an integrated VCO, reducing external component count. The ADF4113BCP does not include a VCO and requires an external VCO or VCO module to complete the PLL loop.
What are the power supply requirements for the ADF4157BCPZ and ADF4113BCP?
Both devices typically operate from a 3.0 V to 3.6 V supply. The ADF4157BCPZ datasheet specifies a 3.0 V to 3.6 V range, and the ADF4113BCP datasheet specifies a 2.7 V to 3.3 V range. Designers should verify exact limits in the respective datasheets.
Which device is better suited for low phase noise applications?
The ADF4157BCPZ offers fractional-N operation with programmable modulus and is designed for low phase noise and spurious performance. The ADF4113BCP is an integer-N PLL with good phase noise but lacks fractional-N flexibility. The choice depends on the specific phase noise and frequency resolution requirements of the application.