STW81100ATR-1 4.4 GHz Multi-Band RF Synthesizer | STMicroelectronics
MPN: STW81100ATR-1 ✓ ActiveSTW81100ATR-1 Overview
A frequency synthesizer is a clock-and-timing integrated circuit that generates a stable output frequency from a reference source. In the hierarchy, the STW81100ATR-1 is an RF frequency synthesizer, a phase-locked-loop device, and a multi-band clock generator. Its integrated VCOs place the oscillator core inside the package, reducing the number of external microwave oscillator components required in an RF signal chain while supporting closed-loop frequency regulation.
The primary feature set includes an integer-N frequency-synthesizer architecture, dual differential integrated VCOs, automatic center-frequency calibration, direct RF output, and internal division. Direct outputs are explicitly listed at 3900 MHz and 4400 MHz. The device is identified as a one-output RF frequency synthesizer in a 28-terminal QCCN surface-mount package and is intended for industrial-grade RF equipment.
Automatic center-frequency calibration is particularly important for an integrated VCO because it helps the synthesizer establish an operating condition suitable for stable closed-loop operation. The integer-N architecture determines frequency through integer division and phase comparison, while the integrated VCO supplies the high-frequency output. Detailed phase-noise, reference-input, tuning-voltage, lock-time, temperature-range, and power-supply values are not included in the supplied source snippets and therefore require confirmation from the manufacturer datasheet.
Typical uses include multi-band RF transceiver modules, microwave communication equipment, test and measurement instruments, and RF subsystems requiring synthesized local-oscillator signals in the 3.9 GHz or 4.4 GHz bands. The industrial temperature grade can suit equipment operating outside consumer-only environments, although the precise rated temperature interval must be obtained from the datasheet.
When designing around this IC, verify the complete reference, charge-pump, loop-filter, supply, and RF output network against the manufacturer application guidance. Preserve the exposed-pad thermal and grounding requirements of the 28-pin VFQFN package, and validate lock behavior, spur performance, and phase noise in the intended channel plan rather than relying only on the maximum listed output frequency.
This page consolidates distributor availability, verified catalog attributes, related family information, and practical RF design considerations. It also distinguishes documented facts from parameters not present in the supplied data, providing a transparent basis for footprint review and manufacturer-datasheet confirmation before a drop-in design decision.
Drop-in alternatives for STW81100ATR-1 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
STW81100ATR
✅ Drop-In📋 Reference alternative (not in catalog)
STW81101ATR
✅ Drop-InContact for price
View Datasheet →STW81100ATR-1 Specifications
| Product Type | Multi-band RF frequency synthesizer with integrated VCOs |
| Frequency Synthesizer Architecture | Integer-N |
| Maximum Listed Frequency | 4.4 GHz |
| Direct Output Frequency | 3900 MHz |
| High Direct Output Frequency | 4400 MHz |
| Internal Divider Output Frequency | Approximately 2200 MHz |
| Integrated VCO Count | 2 VCOs |
| VCO Architecture | Dual differential integrated VCOs |
| Center Frequency Calibration | Automatic |
| RF Output Count | 1 output |
| Package Type | 28-pin VFQFN with exposed pad |
| Package Code | QCCN |
| Package Shape | Square |
| Number of Terminals | 28 terminals |
| Mounting Type | Surface mount |
| Temperature Grade | Industrial |
STW81100ATR-1 square Pin Configuration Guide
Pin configuration for STW81100ATR-1 (square 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 STW81100ATR-1.
Refer to the datasheet for full pin configuration.
Typical Applications
STW81100ATR-1 is suitable for 6 applications: Multi-Band RF Transceiver, Microwave Communication Equipment, RF Test and Measurement Instrumentation, Industrial RF Control Systems, Wireless Backhaul and RF Links, Frequency-Modulated RF Signal Sources.
Multi-Band RF Transceiver
The STW81100ATR-1 fits a multi-band transceiver local-oscillator role because it combines an integer-N frequency synthesizer with two differential integrated VCOs and automatic center-frequency calibration. Its documented direct outputs at 3900 MHz and 4400 MHz make it directly relevant to RF links operating in those bands, while its one-output configuration suits designs requiring one synthesized LO per device. The advantage is reduced dependence on external microwave oscillator assemblies, although phase noise, spur performance, lock time, reference requirements, and output power must be verified from the manufacturer datasheet before setting channel spacing and sensitivity targets.
Recommended
Microwave Communication Equipment
For microwave communication equipment, the STW81100ATR-1 provides a compact way to generate a 3900 MHz or 4400 MHz signal from a controlled reference source. Integration of the VCO core within the 28-pin VFQFN can shorten the RF oscillator path and simplify the bill of materials relative to a discrete oscillator-plus-divider arrangement. The integer-N loop architecture is useful for channelized transceivers, but reference phase noise, fractional-N versus integer-N constraints, loop filter design, and channel spacing remain central design variables. The supplied evidence does not specify those performance limits, so laboratory validation is required.
Recommended
RF Test and Measurement Instrumentation
The STW81100ATR-1 is a candidate for RF test equipment that requires an internally generated 3.9 GHz or 4.4 GHz source in a compact surface-mount assembly. Automatic VCO center-frequency calibration can support repeatable initialization, while the integrated dual differential VCO structure offers potential tuning range across multiple RF bands. For instrumentation, the decisive metrics are phase noise, spur level, lock time, output power, frequency accuracy, and temperature stability; none of these numerical limits appears in the supplied snippets. Engineers should therefore treat the documented band coverage as the starting point and evaluate the full manufacturer specification and measured performance.
Recommended
Industrial RF Control Systems
The STW81100ATR-1's industrial temperature-grade classification makes it a candidate for factory automation, industrial sensing, and RF control subsystems that synthesize a local reference near the 4 GHz region. Its one-output arrangement can support a single RF channel, while the exposed-pad VFQFN package supports compact board placement with appropriate thermal routing. Because the exact operating-temperature interval and electrical ratings were not supplied, the grade designation alone cannot qualify the device for a particular industrial control point. Confirm those limits, along with reference tolerance and supply requirements, against the datasheet before production release.
Recommended
Wireless Backhaul and RF Links
The STW81100ATR-1 can be evaluated for wireless backhaul and other high-frequency links requiring a synthesized source in the 3900 MHz or 4400 MHz bands. Automatic center-frequency calibration is relevant during startup, while integer-N synthesis offers a straightforward frequency-generation architecture when integer division ratios are acceptable. A practical design must compare phase noise and spurious signals against the receiver's sensitivity and adjacent-channel requirements. It must also isolate the RF output and reference input from digital, power, and switching-converter noise so that the synthesizer's performance is not compromised by board-level implementation.
Recommended
Frequency-Modulated RF Signal Sources
For compact RF signal-source or modulation subsystems, the STW81100ATR-1 combines frequency synthesis and integrated VCO generation in one 28-pin VFQFN device. The documented 4.4 GHz maximum frequency provides a useful framework for designing around the 3900 MHz and 4400 MHz direct-output bands. Its suitability for precise modulation depends on reference jitter, tuning resolution, loop bandwidth, and output linearity, none of which is available in the supplied snippets. Use the manufacturer application information to establish the control path and then verify modulation fidelity and unwanted sidebands on prototype hardware.
Recommended
Recommended Products Summary
Engineering reference data for STW81100ATR-1 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | STW81100ATR | STW81101ATR |
|---|---|---|---|
| Package | 28-pin VFQFN exposed pad (QCCN) | 28-pin VFQFN exposed pad (QCCN) | 28-pin VFQFN exposed pad (QCCN) |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics |
Key Differentiators
- Documented multi-band direct output coverage (vs STW81101ATR)
- Integrated dual-differential VCO architecture (vs STW81100ATR)
- Single-output integration in a compact exposed-pad package (vs STW81101ATR)
Design Notes
Route the 28-pin QCCN footprint directly from the manufacturer mechanical drawing rather than treating it as a generic QFN-28 land pattern. The exposed pad must use the specified thermal and ground-via arrangement, while reference, synthesizer-control, supply, and RF-output nets should be kept physically separate where the datasheet layout example permits. Confirm pad length, width, pitch, and exposed-pad geometry during footprint review because those dimensions were not included in the supplied source data.
Use the manufacturer's recommended loop-filter, reference, decoupling, and RF-output networks, then validate phase noise and spurious performance on the final PCB. A clean synthesizer can still be degraded by reference supply noise, shared return-current paths, switching-node coupling, or an improperly terminated RF output. Measure lock behavior and spectral artifacts with the intended reference source because the supplied excerpts do not provide phase-noise, spur, lock-time, or reference-input limits.
Treat the exposed pad as the principal thermal path and provide copper area and vias according to STMicroelectronics package guidance. The supplied data identifies a VFQFN exposed-pad package but does not provide junction-to-ambient resistance or local power dissipation, so a numerical thermal estimate would be unsupported. Check the complete datasheet for maximum supply voltage, RF-output conditions, and package thermal ratings before selecting the exposed-pad copper area for the final board.
Compliance Information
The supplied sources identify the STW81100ATR-1 as an industrial-grade IC but do not state RoHS, REACH, halogen-free, conflict-minerals, or automotive-qualification status. AEC-Q100 is marked not_applicable because no automotive qualification is evidenced, not because an automotive exclusion is explicitly stated.
