Part A
ADF4156BCPZ
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 1350 個数
- Package
- WFQFN-20
- Series
- クロックタイミング - クロックジェネレータ、PLL、周波数シンセサイザ
Replacement verdict
Compatible functional replacement candidate
The ADF4156BCPZ and ADF4154BCPZ-RL are both fractional-N PLL frequency synthesizers in a compatible 20-lead LFCSP package with overlapping supply and temperature ranges, making the ADF4156BCPZ a viable functional replacement candidate for the ADF4154BCPZ-RL. Designers should validate RF performance, charge pump current settings, and register map differences against the target application before substitution.
Package Type
High match
Supply Voltage Range
High match
Charge Pump Current
Validation required
Register Map Compatibility
Validation required
Parts at a glance
Part B
ADF4154BCPZ-RL
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 7852 個数
- Package
- WFQFN-20
- Series
- クロックタイミング - クロックジェネレータ、PLL、周波数シンセサイザ
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 | ADF4154BCPZ-RL | Why it matters |
|---|---|---|---|
| Maximum RF Input Frequency | 6 GHz | 4 GHz | Determines the highest frequency the PLL can synthesize; the ADF4156 supports higher-frequency applications. |
| Maximum PFD Frequency | 32 MHz | 32 MHz | Sets the phase frequency detector rate, which affects phase noise and lock time performance. |
| Modulus (Fractional Resolution) | 2^25 (25-bit) | 2^25 (25-bit) | Higher fractional modulus enables finer frequency resolution and lower spurious levels in fractional-N operation. |
| Charge Pump Current (Programmable) | Up to 5 mA | Up to 5 mA | Charge pump current influences loop filter design, lock time, and phase noise; both offer similar programmability. |
| Supply Voltage Range | 2.7 V to 3.3 V | 2.7 V to 3.3 V | Defines the operating voltage compatibility with the host system and power supply design. |
| Package Type | 20-Lead LFCSP | 20-Lead LFCSP | Package footprint and thermal characteristics affect PCB layout and drop-in substitutability. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Ensures reliable operation across the intended environmental conditions of the application. |
| Interface Type | 3-Wire SPI | 3-Wire SPI | Serial interface compatibility determines whether the device can be controlled by the same host microcontroller without firmware changes. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADF4156BCPZ | ADF4154BCPZ-RL |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| 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 | 4GHz |
| Divider / Multiplier | Yes/Yes | No/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 ADF4156BCPZ and ADF4154BCPZ-RL?
The ADF4156BCPZ is a 6.2 GHz fractional-N PLL synthesizer, while the ADF4154BCPZ-RL is a 4 GHz fractional-N PLL synthesizer. The ADF4156 offers a higher maximum RF input frequency (6.2 GHz vs 4 GHz), a higher maximum PFD frequency (32 MHz vs 25 MHz), and a wider operating frequency range. Both are housed in a 20-lead LFCSP package and share a similar register architecture, but the ADF4156 provides extended frequency capability for higher-band applications.
Are the ADF4156BCPZ and ADF4154BCPZ-RL pin-compatible?
Yes, both devices are offered in a 20-lead LFCSP (CP-20-1) package with the same pinout. This allows a common PCB footprint; however, firmware and register settings must be adjusted because the two devices have different maximum operating frequencies and some register bit definitions differ. Designers should verify the register map in the respective datasheets before substituting one for the other.
What is the maximum RF input frequency for each device?
The ADF4156BCPZ supports RF input frequencies up to 6.2 GHz. The ADF4154BCPZ-RL supports RF input frequencies up to 4 GHz. The choice between them depends on the required output frequency of the synthesizer in the target application.
What is the maximum phase frequency detector (PFD) frequency for each part?
The ADF4156BCPZ has a maximum PFD frequency of 32 MHz. The ADF4154BCPZ-RL has a maximum PFD frequency of 25 MHz. A higher PFD frequency generally allows a wider loop bandwidth and lower in-band phase noise, which may favor the ADF4156 in demanding high-frequency designs.
Do both devices support fractional-N operation?
Yes, both the ADF4156BCPZ and ADF4154BCPZ-RL are fractional-N frequency synthesizers. They support fractional-N division with programmable modulus, allowing fine frequency resolution without requiring a very low reference frequency. Both also support integer-N mode for applications where fractional spurs must be avoided.
What supply voltage and current consumption do these devices require?
Both devices operate from a nominal 3.0 V to 3.6 V supply (3.3 V typical). The ADF4156BCPZ typically draws about 20 mA from the 3.3 V supply, while the ADF4154BCPZ-RL typically draws about 17 mA. Actual current depends on the programmed settings, such as charge pump current and RF divider configuration. Designers should consult the respective datasheets for detailed supply current specifications.
Can the ADF4154BCPZ-RL be used as a drop-in replacement for the ADF4156BCPZ?
Not directly. Although both share the same 20-lead LFCSP package and pinout, the ADF4154BCPZ-RL has a lower maximum RF input frequency (4 GHz vs 6.2 GHz) and a lower maximum PFD frequency (25 MHz vs 32 MHz). If the target design operates within the ADF4154's limits and the register settings are updated accordingly, it may be usable; otherwise, the ADF4156BCPZ should be retained. Always validate against the manufacturer datasheets before substitution.
What are the typical applications for each device?
The ADF4156BCPZ is typically used in higher-frequency applications such as microwave point-to-point radios, satellite communications, and instrumentation requiring RF outputs up to 6.2 GHz. The ADF4154BCPZ-RL is typically used in wireless infrastructure, base stations, and general-purpose frequency synthesis up to 4 GHz. Both are suitable for local oscillator generation in RF and microwave systems within their respective frequency ranges.