SI5351A-B-GTR - 200MHz I2C CMOS Clock Generator, 2-Output, MSOP-10 | Skyworks
Référence : SI5351A-B-GTR ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $1.95 | $1,95 |
| 10 | $1.74 | $17,40 |
| 100 | $1.42 | $142,00 |
| 500 | $1.18 | $590,00 |
| 1 000 | $0.95 | $950,00 |
SI5351A-B-GTR Présentation
A clock generator is a semiconductor IC that produces one or more precise timing signals used to synchronize logic in digital systems. The SI5351A-B-GTR belongs to the broader category of timing ICs, which sits between frequency synthesizers (PLL/VCO blocks) and standard fixed-frequency oscillators. Within the timing hierarchy, it is classified as a programmable CMOS clock generator, offering finer frequency resolution than a fixed-frequency XO and lower cost and complexity than a full VCXO/PLL solution. Engineers reach for the Si5351 family when fixed oscillators cannot deliver the exact multiple frequencies a system requires, especially in mixed-signal designs, SDR front-ends, and embedded video/multi-rate audio applications.
Key features include independent per-output MultiSynth fractional-N dividers, user-configurable drive strength (2 mA, 4 mA, 6 mA, 8 mA), a spread-spectrum option for EMI reduction, and ultra-low jitter measured at 70 ps pk-pk typical. The two LVCMOS outputs support independently selectable output enable and phase-offset adjustment, allowing fine skew control between clock domains. The device operates from a single 2.5 V or 3.3 V supply with low quiescent current draw and integrates an I2C interface (up to 400 kHz) for in-system register configuration.
The architecture is built around two PLLs and per-output MultiSynth fractional dividers that decouple output frequencies from integer-multiple relationships, enabling any-rate-any-output synthesis. The internal VCO is calibrated automatically, eliminating manual loop-filter components and supporting the wide 8 kHz to 200 MHz output range from a single silicon revision.
Typical applications include amateur-radio SDR QRP transceivers, FPGA reference clocks, multi-rate audio interface clocks (e.g., 44.1/48/96 kHz families), microcontroller clock-tree generation, and HDMI/USB peripheral timing. When designing with this device, ensure the reference crystal load capacitance matches the onboard load capacitors, and follow the ClockBuilder Pro configuration utility to generate the I2C register map for non-standard frequency plans.
Alternatives de remplacement direct pour SI5351A-B-GTR — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec SI5351A-B-GTR (même facteur de forme et même empreinte) — différant par Function, Input Reference, Operating Temperature Range, Output Frequency Range, Package.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
SI5351A-B-GT
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
SI5351B-B-GTR
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
SI5351A-B05130-GTR
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
SI5351A-B05336-GTR
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
MS5351M
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
SI5351A-B-GTR Spécifications
| Fonction | I2C-programmable any-frequency CMOS clock generator |
| Output Count | 2 LVCMOS |
| Output Frequency Range | 8 kHz to 200 MHz |
| Type de sortie | LVCMOS |
| Input Reference | 25 MHz or 27 MHz crystal |
| PLL Count | 2 internal MultiSynth fractional-N PLLs |
| Tension d'alimentation | 2.25 V to 3.6 V |
| Jitter (Cycle to Cycle) | 70 ps pk-pk typical (high drive strength) |
| I2C Interface Speed | Up to 400 kHz (Fast-mode) |
| Drive Strength Options | 2 mA / 4 mA / 6 mA / 8 mA |
| Output Enable Control | Per-output software control |
| Phase Offset Adjustment | Per-output programmable |
| Spread Spectrum | Yes (down-spread center, configurable) |
| Boîtier | 10-pin MSOP (3.0 mm width), tape and reel |
| Plage de température de fonctionnement | -40 C to +85 C (industrial) |
| Statut RoHS | Compliant |
| Lead-Free | Yes |
Configuration des broches de SI5351A-B-GTR
| Broche 1 | SDA — I2C serial data |
| Broche 2 | SCL — I2C serial clock |
| Broche 3 | GND — Ground |
| Broche 4 | XIN — Crystal input (25 or 27 MHz) |
| Broche 5 | XOUT — Crystal output |
| Broche 6 | VDD — Core supply (2.25-3.6 V) |
| Broche 7 | CLK0 — LVCMOS output 0 |
| Broche 8 | VDDO — Output supply rail |
| Broche 9 | CLK1 — LVCMOS output 1 |
| Broche 10 | GND — Ground |
Applications typiques
SI5351A-B-GTR convient pour 6 applications: Amateur Radio SDR/QRP Transceiver LO, FPGA Reference Clock Tree, Multi-Rate Audio Interface Clock, Microcontroller Clock Tree Distribution, Industrial Sensor Aggregation Hubs, Portable / Battery-Powered Test Gear.
Amateur Radio SDR/QRP Transceiver LO
The SI5351A-B-GTR is the de-facto reference clock for QRP Labs and other ham-radio SDR kits, where its dual independent MultiSynth outputs let one CLK drive the quadrature VFO/Mixer LO and the other drive the BFO at exact receive-sideband frequencies. Specs that fit: 8 kHz to 200 MHz synthesis lets the BFO cover 9 MHz IF systems with sub-Hz resolution, while the 25 MHz onboard reference keeps parts count minimal. Unlike discrete DDS chips it needs no high-speed DAC and runs from a single 3.3 V rail.
Recommandé
FPGA Reference Clock Tree
FPGAs and SoCs that need two unrelated reference frequencies (e.g., 50 MHz for fabric and 25 MHz for PHY, or 74.25 MHz and 148.5 MHz for HDMI video) drop in the SI5351A-B-GTR as a single-chip solution. The 200 MHz ceiling comfortably covers most embedded video formats, while the independent phase-offset register (per output, 0 to 360 degrees in coarse steps) lets the designer align two clock edges for source-synchronous interfaces. Compared to a fixed oscillator plus PLL pair, this shrinks BOM and removes manual loop-filter calculation.
Recommandé
Multi-Rate Audio Interface Clock
USB and HDMI audio designs that need to switch between 44.1 kHz, 48 kHz, 96 kHz and 192 kHz sample-rate families benefit from the SI5351A-B-GTR's non-integer divider architecture, which synthesizes each MCLK from a common 25 MHz crystal without jitter spikes during rate changes. The two LVCMOS outputs let one drive the codec MCLK while the other supplies the FPGA fabric clock; both stay sample-coherent. The device's small MSOP-10 footprint fits inside compact USB audio dongle enclosures.
Recommandé
Microcontroller Clock Tree Distribution
Embedded boards that need both a high-speed main oscillator (e.g., 168 MHz for an STM32-class MCU) and a low-power RTC domain clock (32.768 kHz) use the SI5351A-B-GTR's two outputs to serve each from one IC. The I2C bus allows the firmware to change frequencies in software for low-power sleep modes, eliminating mechanical frequency-switch jumpers. Output enable and per-output skew control simplify power-sequenced boot, and the 3 V supply matches typical MCU rails without an extra LDO stage.
Recommandé
Industrial Sensor Aggregation Hubs
Industrial controllers that aggregate multi-rate sensors (e.g., 1 MHz SPI ADC, 10 MHz UART, and a 25 MHz Ethernet reference) leverage the SI5351A-B-GTR to drive three independent domains from one crystal and shrink board area versus three discrete oscillators. The -40 C to +85 C industrial temperature range supports factory-floor deployment, and the spread-spectrum option helps meet EN 55022 EMI limits without additional shielding. Fast-mode I2C (400 kHz) keeps configuration registers updateable on the fly.
Recommandé
Portable / Battery-Powered Test Gear
Handheld spectrum analyzers, function generators, and bench meters use the SI5351A-B-GTR to drive both an ADC sampling clock and an LO DDS reference from one chip, keeping battery draw low (single 3.3 V rail, low quiescent current) and minimizing board area for portable form factors. Independent output enable lets designers power-down unused domains when measuring battery life, and the spread-spectrum option mitigates radiated emissions that would otherwise require extra shielding in compact enclosures.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour SI5351A-B-GTR — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | SI5351A-B-GT | SI5351B-B-GTR | SI5351A-B05130-GTR | SI5351A-B05336-GTR | MS5351M |
|---|---|---|---|---|---|---|
| Package | MSOP-10 | MSOP-10 - same | MSOP-10 - same | MSOP-10 - same | MSOP-10 - same | MSOP-10 - same |
| Brand | Skyworks | Skyworks | Skyworks | Skyworks | Skyworks | Skyworks (third-party-qualified) |
| Output Count | 2 | 2 | 2 | 2 | 2 | 2 |
| Output Frequency Range | 8 kHz to 200 MHz | 8 kHz to 200 MHz | 8 kHz to 200 MHz | 8 kHz to 200 MHz (custom default) | 8 kHz to 200 MHz (custom default) | 8 kHz to 200 MHz |
| VCXO Pull Range | None | None | +/-250 ppm integrated VCXO | None | None | None |
| Packaging Form | Tape & Reel (3000) | Tube | Tape & Reel | Tape & Reel | Tape & Reel | Tape & Reel |
| Supply Voltage | 2.25 V to 3.6 V | 2.25 V to 3.6 V | 2.25 V to 3.6 V | 2.25 V to 3.6 V | 2.25 V to 3.6 V | 2.25 V to 3.6 V |
| Custom Default Frequency | Not pre-programmed | Not pre-programmed | Not pre-programmed | 51.3 kHz example (factory) | 53.336 MHz example (factory) | Not pre-programmed |
Principaux différenciateurs
- On-chip dual MultiSynth fractional-N architecture (vs SI5351A-B05130-GTR)
- Drop-in upgrade path to integrated VCXO (vs SI5351B-B-GTR)
- Skyworks-authorized third-party alternative for short supply (vs MS5351M)
Notes de conception
Place the 25 MHz or 27 MHz crystal within 5 mm of the XIN/XOUT traces and route both pins over a continuous ground plane. Keep the crystal body away from switching converters and I/O connectors. Skyworks ClockBuilder Pro documentation recommends using 1% tolerance crystals with less than 10 ppm initial accuracy and matching load capacitance to the onboard trim caps (factory-set to 8 pF). Use short, equal-length XIN/XOUT traces to minimize jitter contribution from the reference loop.
The SI5351A-B-GTR requires two supply rails: VDD (core) and VDDO (output driver). Both may be tied to a common 3.3 V rail, but if the output drivers must swing at 1.8 V while the core runs at 3.3 V, route VDDO separately and decouple with a 100 nF X7R capacitor placed within 2 mm of pin 8. Skyworks recommends placing a 10 uF bulk capacitor plus a 100 nF X7R bypass cap on VDD (pin 6) for jitter stability.
The factory-default I2C address is 0x60; if two SI5351 devices are on the same bus, the address strap must be set differently per datasheet section on hardware addressing. Always run the ClockBuilder Pro configuration utility for any non-trivial frequency plan - manual register programming without proper PLL feedback-divider and MultiSynth setup will produce no output or invalid frequencies. Finally, when using spread spectrum, check that downstream PLLs have not been locked to the input clock, because spread modulation will cause the second-stage PLL to lose lock.
Informations de conformité
RoHS and lead-free confirmed by Skyworks product page. AEC-Q100 automotive grade is NOT offered for this part - use a custom-programmed variant if automotive qualification is required.
