Part A
ADF4118BRUZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7756 PCS
- Package
- TSSOP-16
- Series
- Clock-Timing - Clock Generators, PLLs, Frequency Synthesizers
Replacement verdict
Compatible functional replacement candidate
The ADF4118BRUZ and ADF4154BRU are both single-channel integer-N PLL frequency synthesizers in 16-lead TSSOP packages with a 3-wire SPI interface and comparable supply voltage ranges, making them functionally interchangeable in many fractional-N and integer-N synthesizer designs. However, the ADF4154BRU offers a higher maximum RF input frequency and a wider operating temperature range, so the ADF4118BRUZ should be validated against the target frequency plan and thermal environment before substitution.
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
ADF4154BRU
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 8393 PCS
- Package
- TSSOP-16
- 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 | ADF4118BRUZ | ADF4154BRU | Why it matters |
|---|---|---|---|
| Maximum Operating Frequency | 3 GHz | 4 GHz | Determines the highest RF output frequency the PLL synthesizer can support; a higher limit allows use in higher-band applications. |
| Number of RF Inputs | 2 (dual) | 1 (single) | Dual RF inputs allow switching between two sources without external multiplexing, which affects board-level architecture and flexibility. |
| Programmable Modulus / Fractional Capability | Integer-N only | Fractional-N | Fractional-N operation enables finer frequency resolution and lower phase noise for a given reference, affecting loop filter design and channel spacing. |
| Supply Voltage Range | 2.7 V to 3.3 V | 2.7 V to 3.3 V | Confirms the devices operate from the same low-voltage rail, which is important for direct power-supply compatibility. |
| Package Type | 16-Lead TSSOP | 16-Lead TSSOP | Identical package and pin count simplify PCB footprint reuse, though pinout differences must still be verified. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Matching industrial temperature ranges ensure both parts are suitable for the same environmental conditions. |
| Charge Pump Current (Programmable) | Programmable, up to 5 mA | Programmable, up to 5 mA | Charge pump current affects loop bandwidth and phase noise; similar ranges allow comparable loop filter design. |
| Digital Interface | 3-wire serial (SPI-compatible) | 3-wire serial (SPI-compatible) | A common serial control interface allows reuse of the same microcontroller firmware and timing, easing substitution. |
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 | ADF4118BRUZ | ADF4154BRU |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Type | Clock/Frequency 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 | 3GHz | 4GHz |
| Divider / Multiplier | Yes/No | No/Yes |
| Voltage - Supply | 2.7V ~ 5.5V | 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 ADF4118BRUZ and the ADF4154BRU?
The ADF4118BRUZ is a fractional-N PLL synthesizer with an integrated VCO operating from 2.7 GHz to 3.3 GHz, while the ADF4154BRU is a fractional-N PLL synthesizer without an integrated VCO, requiring an external VCO and operating up to 4 GHz. The ADF4118BRUZ includes an on-chip VCO, whereas the ADF4154BRU is a standalone PLL IC intended for use with an external VCO.
Are the ADF4118BRUZ and ADF4154BRU pin-compatible?
No. The ADF4118BRUZ is supplied in a 20-lead TSSOP package, while the ADF4154BRU is supplied in a 16-lead TSSOP package. The different pin counts and pin functions mean they are not pin-compatible and cannot be dropped into the same PCB footprint without redesign.
What is the maximum operating frequency of each device?
The ADF4118BRUZ integrates a VCO with an output frequency range of 2.7 GHz to 3.3 GHz. The ADF4154BRU is a PLL synthesizer that supports RF input frequencies up to 4 GHz when paired with an appropriate external VCO.
Do both devices support fractional-N operation?
Yes. Both the ADF4118BRUZ and the ADF4154BRU are fractional-N frequency synthesizers, allowing fine frequency resolution without requiring a very low reference frequency. Both use sigma-delta modulation for fractional-N operation.
What supply voltage do the ADF4118BRUZ and ADF4154BRU require?
Both devices operate from a nominal 3.0 V to 3.6 V supply, with a typical operating voltage of 3.3 V. Designers should confirm the exact supply range against the respective manufacturer datasheets for the specific grade and conditions.
Can the ADF4154BRU replace the ADF4118BRUZ in an existing design?
Not directly. The ADF4118BRUZ includes an integrated VCO, while the ADF4154BRU requires an external VCO and has a different package and pinout. A replacement would require adding an external VCO, redesigning the PCB layout for the 16-lead package, and revalidating the loop filter and RF matching network.
Which device is better suited for compact integrated synthesizer designs?
The ADF4118BRUZ is better suited for compact designs because it integrates the VCO on-chip, reducing external component count and board area. The ADF4154BRU offers more flexibility for designs requiring an external VCO with a different frequency range or performance characteristics.