STW81200TR - 6 GHz Fractional-N RF Synthesizer | STMicroelectronics (Tape & Reel)
MPN: STW81200TR ✓ ActiveSTW81200TR Overview
A frequency synthesizer generates or converts an output frequency from a reference source while controlling phase and frequency. A PLL-based synthesizer belongs to the clock and timing IC hierarchy, where it extends beyond ordinary clock distribution into phase-locked-loop frequency generation, RF signal conditioning, modulation, and waveform conversion.
The device's headline capabilities are its 46.875 MHz-to-6 GHz tuning range, fractional-N or integer-N operation, and three integrated low-phase-noise VCOs. Integrated LDOs include over-current protection, internal power ramping, and an external 100 nF feed-forward bypass requirement described in the manufacturer datasheet. This integration supports compact RF designs while reducing the number of separate frequency-generation blocks.
Architecturally, STW81200TR supports both fractional-N synthesis for programmable frequency relationships and integer-N synthesis for channels that do not require fractional division. The three VCO choices allow the system designer to optimize frequency coverage and phase-noise behavior across the operating band. The wide range makes the synthesizer relevant to RF communications, test equipment, and frequency-conversion stages.
Typical applications include wideband RF transceivers, local oscillators, laboratory synthesizers, communication infrastructure, and instrumentation requiring programmable output above 500 MHz. Its principal trade-off is integration: fewer external frequency-generation blocks are required, but the design must follow the datasheet's reference, bypass-capacitor, grounding, and exposed-pad requirements.
Place the 100 nF feed-forward capacitor exactly as specified in the manufacturer datasheet and provide the required supply decoupling at every LDO. Keep the reference path short and controlled, connect the exposed pad to the recommended thermal and ground plane, and validate phase-noise, spur, and settling performance across the intended frequency plan. This page combines verified distributor data, official STMicroelectronics documentation, application guidance, and procurement information.
Drop-in alternatives for STW81200TR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
STW82600T
✅ Drop-In📋 Reference alternative (not in catalog)
STW81200TR Specifications
| Product Type | Wideband RF PLL fractional/integer frequency synthesizer |
| Architecture | Dual architecture: Fractional-N and Integer-N |
| Minimum Synthesis Frequency | 46.875 MHz |
| Maximum Synthesis Frequency | 6 GHz |
| Output Count | 1 output |
| VCO Count | 3 low phase-noise VCOs |
| Integrated Supply Support | Integrated LDOs |
| External Feed-Forward Bypass Capacitor | 100 nF |
| LDO Short-Circuit Protection | Over-current protection |
| LDO Startup Control | Internal power ramping |
| Package | 36-VFQPN with exposed pad |
| Mounting Type | Surface mount |
STW81200TR 36-vfqpn with exposed pad Pin Configuration Guide
Pin configuration for STW81200TR (36-vfqpn with 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 STW81200TR.
Refer to the datasheet for full pin configuration.
Typical Applications
STW81200TR is suitable for 6 applications: Wideband RF Transceiver Local Oscillator, Programmable Communications Test Source, Instrumentation and Signal-Analysis RF Front End, Frequency-Conversion Stage, RF Communication Infrastructure, Laboratory RF Signal Generator.
Wideband RF Transceiver Local Oscillator
The STW81200TR fits a programmable local-oscillator function in a wideband RF transceiver because it synthesizes from 46.875 MHz to 6 GHz and supports both Fractional-N and Integer-N architectures. Place the synthesizer according to the manufacturer reference design, provide the required 100 nF LDO feed-forward capacitor, and validate the selected VCO against the receiver and transmitter frequency plan. The main benefit is flexible channel generation without a separate off-chip oscillator block. The design trade-off is that loop filters, reference quality, layout, and spur requirements still determine usable adjacent-channel performance.
Recommended
Programmable Communications Test Source
For communications test equipment, the STW81200TR provides a programmable RF source across 46.875 MHz to 6 GHz, allowing one synthesizer platform to cover multiple test frequencies. Its dual Fractional-N and Integer-N operation supports different channel-routing requirements, while the three-VCO architecture gives designers selectable RF paths. Engineers should characterize settling time, phase noise, and spurs at every required test point. Keep the reference and RF paths controlled because a clean digital programming interface alone does not guarantee low phase noise or repeatable RF output.
Recommended
Instrumentation and Signal-Analysis RF Front End
The STW81200TR is appropriate for instrumentation that needs a programmable RF excitation source or local oscillator between 46.875 MHz and 6 GHz. Fractional-N operation can simplify non-integer frequency relationships, while Integer-N operation supports integer divider plans. Use the exposed pad for thermal dissipation and follow the official layout for the reference, LDO bypass capacitors, and RF output. Validate the complete measurement path because synthesizer phase noise and spurs can limit the accuracy of the downstream analyzer or receiver.
Recommended
Frequency-Conversion Stage
The STW81200TR can serve as the programmable synthesizer in a frequency-conversion stage that requires local-oscillator tuning across a wide RF span. Its 6 GHz upper synthesis frequency and selectable VCO architecture make it relevant for RF conversion blocks above conventional low-frequency clock-generation ranges. The design must account for output drive, matching, unwanted spurs, reference phase noise, and loop bandwidth. Because the device includes LDOs, the required bypass network and exposed-pad thermal path are central to achieving repeatable conversion performance.
Recommended
RF Communication Infrastructure
The STW81200TR is relevant to RF communication infrastructure requiring programmable synthesis from 46.875 MHz through 6 GHz. Its dual Fractional-N and Integer-N architecture provides flexibility for channel plans and local-oscillator generation, while the integrated LDOs can simplify the power-distribution section. In infrastructure equipment, verify long-term phase-noise behavior, temperature range, output stability, and regulatory channel requirements against the official datasheet. The exposed-pad footprint and sensitive RF layout require careful thermal and grounding implementation.
Recommended
Laboratory RF Signal Generator
The STW81200TR can serve as the core frequency-generation element in a laboratory RF signal generator covering 46.875 MHz to 6 GHz. Programmable Fractional-N and Integer-N modes support different output-frequency combinations, and the three low-phase-noise VCOs provide architectural flexibility. A laboratory instrument still needs accurate calibration, reference isolation, output attenuation or amplification, and enclosure or board-level thermal design. Evaluate settling behavior and phase noise at the instrument's bandwidth and frequency limits rather than relying only on the headline synthesis range.
Recommended
Recommended Products Summary
Engineering reference data for STW81200TR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | STW82600T |
|---|---|---|
| Brand | STMicroelectronics | STMicroelectronics |
| Package | 36-VFQPN with exposed pad | 36-VFQPN exposed pad — package match is provisional |
| Product Type | RF PLL fractional/integer frequency synthesizer | 6 GHz synthesizer — exact architecture details not supplied |
| Maximum Frequency | 6 GHz | 6 GHz according to cross-reference snippet |
| Drop-In Status | Target device | Provisional; pin and parameter verification required |
Key Differentiators
- Wide frequency coverage in one RF synthesizer (vs STW82600T)
- Integrated multi-VCO architecture (vs STW82600T)
- Manufacturer-documented LDO noise integration (vs STW82600T)
- Direct 6 GHz positioning (vs STW82600T)
Design Notes
Use the official STMicroelectronics datasheet layout as the authority for the 36-VFQPN footprint, exposed-pad connection, reference routing, RF output path, and ground return. Keep the 100 nF feed-forward capacitors for the LDOs short and close to their specified pins. Do not infer a generic QFN land pattern or route the RF output over split or noisy return paths. A controlled reference and compact RF layout are essential for predictable phase noise and spur performance.
The STW81200TR uses a 36-VFQPN exposed pad, so thermal design is part of the electrical design. Connect the pad according to the manufacturer datasheet and provide an uninterrupted copper thermal path without compromising the RF return. Estimate the local dissipation from the selected supply, output-current, and RF-output conditions before finalizing copper area. The supplied data does not provide a thermal-resistance value, so a numerical junction-temperature estimate would require that missing datasheet parameter.
A synthesizer can lock in the laboratory yet fail in production if the reference, bypass capacitors, grounding, or RF output matching are treated as secondary. Confirm the required 100 nF LDO feed-forward capacitor, preserve recommended component placement, and validate phase noise, spurs, settling, and output level over temperature and supply tolerance. Do not substitute STW82600T without proving its pinout and electrical behavior against the STW81200TR datasheet.
Compliance Information
The supplied verified data does not include explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals statements. No compliance claim is inferred.
