HMC704LP4E - 8 GHz 19-Bit Fractional-N PLL | Analog Devices
MPN: HMC704LP4E ⚠ Last Time Buy| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
HMC704LP4E Overview
A fractional-N PLL is a frequency synthesizer that uses a controllable divider ratio to synthesize a precise output frequency from a stable reference. In the signal-chain hierarchy, this PLL belongs to clock generation and timing, then to frequency synthesis, and finally to the broader semiconductor and RF signal-control categories. Its programmable synthesis capability is useful when a system needs a local clock, modulation capability, or flexible frequency relationship between a reference source and downstream circuitry.
The HMC704LP4E combines an 8 GHz synthesizer identity with a 19-bit fractional-N control word. The verified distributor listing identifies it as an integer-N/fractional-N clock-generation IC with a 24-VFQFN exposed-pad package. Its ultra-low-spurious design target makes it relevant to RF, communications, test-and-measurement, and other systems where phase noise, reference spurs, or frequency flexibility affect signal integrity. The exact reference frequency, output-frequency range, divider limits, supply currents, temperature range, and package dimensions are not included in the supplied verified text and require confirmation from the complete manufacturer datasheet.
The silicon-germanium BiCMOS implementation supports the device’s combined high-frequency and low-noise synthesizer architecture. The integrated phase detector, charge pump, VCO, and divider functions reduce the number of external frequency-generation blocks while preserving programmable loop behavior. External loop-filter components and a stable reference supply remain essential design considerations because they determine loop bandwidth, phase noise, reference-spur performance, and settling behavior.
Typical applications include RF transceiver clock generation, communication equipment, frequency-conversion systems, instrumentation, and test equipment. In an RF system, the synthesizer can generate a relationship between the local reference and a required channel or conversion frequency. In instrumentation, programmable frequency generation provides flexibility when the exact output frequency is selected by the host or test sequence.
The most important layout consideration is preserving the low-spurious performance claimed by the manufacturer. Keep the reference and sensitive synthesizer paths short, use a stable low-noise supply, provide suitable decoupling, and follow the manufacturer’s recommended reference and loop-filter implementation. The HMC860LP3E is identified in the verified datasheet snippet as a recommended low-noise, high-PSRR regulator for minimizing external spurious sources.
This page combines the verified HMC704 identity, package, synthesizer description, lifecycle indication, reference-spurious claim, and source links with clearly marked engineering data gaps. It also distinguishes verified facts from parameters that must be checked in the full datasheet before a new PCB or production design is released.
Drop-in alternatives for HMC704LP4E — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
HMC700LP4ETR
✅ Drop-In📋 Reference alternative (not in catalog)
HMC701LP6CETR
✅ Drop-In📋 Reference alternative (not in catalog)
HMC704LP4E Specifications
| Device Type | Fractional-N frequency synthesizer |
| Maximum Synthesizer Frequency | 8 GHz |
| Fractional-N Control Resolution | 19 bit |
| Output Count | 1 output |
| Architecture | Integer-N/fractional-N PLL |
| Process Technology | SiGe BiCMOS |
| Integrated Blocks | Digital phase detector, VCO, VCO divider, reference divider, precision controlled charge pump |
| Reference Spurious Level | Typically below -100 dBc with a well-designed board layout |
| Package | 24-pin VFQFN exposed pad |
| Mounting Type | Surface mount |
HMC704LP4E 24-pin vfqfn exposed pad Pin Configuration Guide
Pin configuration for HMC704LP4E (24-pin vfqfn exposed pad package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for HMC704LP4E.
Refer to the datasheet for full pin configuration.
Typical Applications
HMC704LP4E is suitable for 6 applications: RF Transceiver Clock Generation, Communications Frequency Synthesis, Test and Measurement Instrumentation, Frequency Conversion Systems, Low-Spurious Clock Distribution, RF Signal-Chain Control.
RF Transceiver Clock Generation
The HMC704LP4E fits RF transceiver clock-generation work that requires a programmable fractional-N relationship between a stable reference and a local frequency. Its 8 GHz synthesizer identity and 19-bit fractional-N resolution provide flexible frequency planning for RF signal chains. The manufacturer specifically designed the HMC704 family for ultra-low phase noise and low spurious content, with typical reference spurs below -100 dBc when the board is well designed. Keep the reference, loop filter, supply filtering, and output routing close to the datasheet implementation, and verify lock behavior across the required frequency range.
Recommended
Communications Frequency Synthesis
For communications equipment, HMC704LP4E can provide a programmable local oscillator or clock relationship where low phase noise and controlled spurious content are important. The 8 GHz fractional-N architecture is useful when the system needs flexible frequency ratios rather than a fixed divided clock. Its SiGe BiCMOS implementation integrates the phase detector, VCO, divider, reference divider, and precision controlled charge pump, reducing external synthesis blocks. The final design must verify reference input compatibility, loop bandwidth, supply rails, and output frequency coverage against the complete manufacturer datasheet.
Recommended
Test and Measurement Instrumentation
HMC704LP4E is relevant to programmable test equipment that requires precise, repeatable frequency relationships from one reference source. The 19-bit fractional-N control word can support flexible frequency selection in instrument architectures, while the single-output configuration keeps the synthesis role focused. Low-noise and low-spurious characteristics can improve measurement integrity when the clock is close to sensitive signal paths. Validate output amplitude, lock time, phase noise, reference rejection, and spur levels in the final instrument because the supplied verified data does not specify those values.
Recommended
Frequency Conversion Systems
The HMC704LP4E can be evaluated for frequency-conversion systems requiring a local synthesized frequency with programmable fractional-N control. Its 8 GHz maximum synthesizer identity makes it relevant to RF and microwave signal chains, while the 24-pin VFQFN exposed-pad package supports compact surface-mount implementation. The low-spurious design target can help reduce unwanted products around the desired carrier or clock. Engineers must still confirm output frequency coverage, tuning sensitivity, loop dynamics, and reference spur performance against the complete datasheet before layout release.
Recommended
Low-Spurious Clock Distribution
HMC704LP4E is appropriate for clock-generation stages where reference and output spur levels are more important than a basic low-power clock function. The manufacturer reports typical reference spurious levels below -100 dBc with a well-designed board layout, making careful implementation essential. Use a low-noise reference, controlled supply network, short sensitive traces, and the recommended loop-filter structure. Because the device is LAST TIME BUY, design users should also consider supply continuity and whether a newer supported family member provides a better long-term platform.
Recommended
RF Signal-Chain Control
In RF signal-chain control systems, HMC704LP4E can serve as a programmable frequency source when the design needs local flexibility and low spurious performance. The integrated SiGe BiCMOS synthesizer reduces external blocks, while the fractional-N architecture permits a controlled relationship between the reference and target frequency. The single output should be routed carefully to preserve signal integrity and to avoid unintended coupling from digital programming or switching circuitry. Confirm package pin functions, output power, and loop-filter requirements in the official datasheet before production.
Recommended
Recommended Products Summary
Engineering reference data for HMC704LP4E — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | HMC700LP4ETR | HMC701LP6CETR |
|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices |
Key Differentiators
- Low-spurious architecture (vs HMC700LP4ETR)
- Verified 8 GHz and 19-bit synthesizer identity (vs HMC701LP6CETR)
- SiGe BiCMOS integrated synthesizer blocks (vs HMC700LP4ETR)
Design Notes
The HMC704 datasheet states that reference spurious levels are typically below -100 dBc with a well-designed board layout. Treat that as a system result, not a guaranteed IC-only figure. Keep the reference and loop-filter paths short, use the manufacturer-recommended grounding and decoupling, and minimize coupling from digital programming, regulators, and switching supplies. Measure reference and output spectra on the final PCB because cable, enclosure, clock distribution, and power-supply impedance can materially change the result.
Use a low-noise, high-PSRR regulator when designing the synthesizer supply. The verified HMC704 datasheet specifically recommends a regulator such as the HMC860LP3E to minimize external spurious sources. Confirm the HMC704 supply rails and capacitor values from the complete manufacturer datasheet, then verify regulator noise, load transient response, and filtering at every required output frequency. A regulator with acceptable nominal noise can still create spurs if its bandwidth or layout couples switching artifacts into the PLL reference or supply node.
Start the PCB layout from the official HMC704 reference design and land pattern rather than a generic QFN footprint. The distributor listing confirms a 24-pin VFQFN exposed-pad package, but the supplied data does not provide the pin names or exposed-pad connection. Preserve the package thermal path, place decoupling close to the relevant pins, and route high-speed or sensitive RF-related connections with controlled impedance. Confirm pad dimensions, pin numbering, and solder-mask settings against the manufacturer package drawing before fabrication.
Do not assume that any HMC700-series part is a drop-in replacement solely because it appears in a comparison result. The supplied snippets do not establish identical pin functions, reference ranges, divider programming, output ranges, or package details. For this LAST TIME BUY device, first obtain the official HMC704 datasheet and the exact alternative datasheet, then compare land pattern, pin mapping, supply sequencing, register interface, output range, and RF performance. Without that verification, treat the alternative as a redesign rather than a procurement substitution.
Compliance Information
The supplied verified web snippets do not explicitly provide compliance declarations for HMC704LP4E. Obtain current manufacturer documentation or supplier declarations for the exact ordering code and package. No compliance status has been inferred from the manufacturer or product category.
