Part A
ADF4371BCCZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7563 PCS
- Package
- LGA-48
- Series
- Clock-Timing - Clock Generators, PLLs, Frequency Synthesizers
Replacement verdict
Compatible functional replacement candidate
The ADF4377BCCZ-U3 is a functional replacement candidate for the ADF4371BCCZ, sharing the same 7 mm × 7 mm LFCSP footprint, 3.0 V to 3.6 V supply range, and 3-wire SPI control interface, while extending output frequency coverage to 62.5 MHz–62.5 GHz versus 62.5 MHz–32 GHz. Designers must validate the higher frequency range, revised phase noise and output power characteristics, and the updated register map before committing to a drop-in substitution.
Output Frequency Range
Validation required
Package Type
High match
Supply Voltage
High match
Control Interface
Validation required
Parts at a glance
Part B
ADF4377BCCZ-U3
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 4943 PCS
- 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 | ADF4371BCCZ | ADF4377BCCZ-U3 | Why it matters |
|---|---|---|---|
| Frequency Range (Max) | 32 GHz | 62.5 GHz | The upper output frequency determines whether the part can cover higher-band applications such as mmWave and upper microwave bands; the ADF4377 reaches roughly twice the maximum frequency. |
| Frequency Range (Min) | 62.5 MHz | 800 MHz | The lower frequency limit affects usability in low-band designs; the ADF4371 extends much lower, while the ADF4377 starts higher. |
| Output Channels | 4 differential outputs | 2 differential outputs | The number of outputs determines how many independent signal paths or LO distributions can be driven without external fanout; the ADF4371 offers more outputs. |
| Integrated VCO | Yes | Yes | An integrated VCO simplifies loop filter and layout design and reduces external component count; both parts integrate a VCO, supporting similar architecture. |
| Package Type | 48-lead LFCSP (7 mm x 7 mm) | 48-lead LFCSP (7 mm x 7 mm) | Package footprint and pinout affect PCB layout and drop-in compatibility; matching packages ease board reuse. |
| Supply Voltage | 3.3 V (analog/digital), 5 V (VCO) | 3.3 V (analog/digital), 5 V (VCO) | Supply rails must match the host design's power architecture; identical rails simplify power sequencing and decoupling. |
| Interface | SPI (3-wire/4-wire) | SPI (3-wire/4-wire) | The control interface must be compatible with the host microcontroller; matching SPI support allows firmware reuse. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | The temperature range defines environmental suitability; identical ranges mean similar thermal design constraints. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADF4371BCCZ | ADF4377BCCZ-U3 |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Part Status | Active | Active |
| Type | Integer N Synthesizer (RF) | - |
| PLL | Yes | - |
| Input | CMOS, ECL | - |
| Output | Clock | - |
| Number of Circuits | 1 | - |
| Ratio - Input: Output | 1:5 | - |
| Differential - Input: Output | Yes/Yes | - |
| Frequency - Max | 32GHz | - |
| Divider / Multiplier | Yes/Yes | - |
| Voltage - Supply | 3.15V ~ 3.45V | - |
| Operating Temperature | -40°C ~ 105°C | - |
| Mounting Type | Surface Mount | - |
Frequently asked questions
What are the key differences between the ADF4371BCCZ and the ADF4377BCCZ-U3?
The ADF4371BCCZ is a microwave wideband synthesizer with an integrated VCO covering 62.5 MHz to 32 GHz, while the ADF4377BCCZ-U3 is a microwave wideband synthesizer with an integrated VCO covering 800 MHz to 32 GHz and offering lower phase noise and higher output power in the 800 MHz to 32 GHz range. The ADF4377BCCZ-U3 is supplied in a 48-lead LFCSP package, and the ADF4371BCCZ is supplied in a 48-lead LFCSP package as well; however, the ADF4377BCCZ-U3 is specified as a specific ordering variant (U3) that may differ in packing or grade from the standard ADF4377BCCZ.
Are the ADF4371BCCZ and ADF4377BCCZ-U3 pin-compatible?
Both devices are offered in a 48-lead LFCSP package, but pin compatibility cannot be assumed solely from package type. Designers must verify the pin function assignments and PCB land pattern against the respective Analog Devices datasheets before considering a layout-compatible substitution.
What is the output frequency range of each device?
The ADF4371BCCZ covers an output frequency range of 62.5 MHz to 32 GHz. The ADF4377BCCZ-U3 covers an output frequency range of 800 MHz to 32 GHz. The ADF4371BCCZ therefore extends to lower frequencies, while the ADF4377BCCZ-U3 is specified from 800 MHz upward.
How do the phase noise specifications compare?
The ADF4377BCCZ-U3 is specified with lower phase noise than the ADF4371BCCZ, making it preferable for applications requiring tighter spectral purity. Exact normalized phase noise figures should be taken from the respective Analog Devices datasheets, as they vary with frequency and configuration.
Do both devices integrate a VCO and require an external loop filter?
Yes. Both the ADF4371BCCZ and the ADF4377BCCZ-U3 integrate a VCO and require an external loop filter for PLL operation. The loop filter component values must be calculated for the target loop bandwidth and phase margin using the respective datasheet parameters.
What supply voltages and interfaces do these synthesizers use?
Both devices operate from a nominal 3.3 V analog and digital supply with a separate charge pump supply, and both provide a serial peripheral interface (SPI) for register programming. Designers should confirm exact supply rail tolerances and SPI timing from the Analog Devices datasheets for each part number.
Can the ADF4377BCCZ-U3 directly replace the ADF4371BCCZ in an existing design?
A direct replacement should not be assumed. Although both are 48-lead LFCSP wideband synthesizers with integrated VCOs, differences in frequency range, phase noise, output power, register map, and the U3 ordering variant mean the design must be revalidated against the ADF4377BCCZ-U3 datasheet before substitution.
Which device is better suited for low-frequency synthesis below 800 MHz?
The ADF4371BCCZ is the appropriate choice for output frequencies below 800 MHz, since its specified range extends down to 62.5 MHz. The ADF4377BCCZ-U3 is specified from 800 MHz to 32 GHz and is not characterized for operation below 800 MHz.