What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
SIT9001AI-44-33E4-49.12500 appears to be a SiTime SiT9001 programmable spread-spectrum MEMS oscillator, with a nominal frequency of 49.125 MHz indicated by its ordering code. The exact configuration is not confirmed by an official part page, so treat its voltage, temperature grade, package, stability, spread profile and control-pin function as unverified until SiTime or an authorized distributor confirms the full code. SiTime lists the SiT9001 family as not recommended for new designs and identifies SiT9005 as its replacement family.
What is confirmed about this exact part?
The code identifies the SiT9001 family, which SiTime describes as a programmable spread-spectrum oscillator. The requested full code was not found on an official SiTime part page in the available material; the family datasheet therefore establishes family capabilities, not every setting programmed into this specific SKU.
The final field, 49.12500, strongly indicates a nominal 49.125 MHz output. Confirm that frequency against the original configuration record before production use. The SiT9001 family covers 1–200 MHz, so 49.125 MHz is within the family range. SiTime’s SiT9001 family page and family datasheet are the appropriate starting references, not proof of the exact suffix configuration.
Ordering-code fields: confirmed versus inferred
| Code segment | Likely meaning | Confidence and qualification |
|---|---|---|
SIT9001 |
SiT9001 programmable spread-spectrum oscillator family | Family identity confirmed by SiTime. |
AI |
Likely industrial-temperature and configuration/revision coding | Probable; confirm the exact decode. Comparable SiT9001 AI parts are listed for −40 to +85 °C. |
44 |
Package/configuration identifier | Inferred: a comparable AI-44 part is listed as 7.0 × 5.0 mm with pad. Do not assume that package for this exact part without its decode. |
33 |
Likely 3.3-V supply option | Strongly supported by a comparable official SKU, but confirm for the requested code. |
E4 |
Feature-pin and spread configuration field | Not safely decoded from the family datasheet alone; exact control behavior and modulation settings remain unknown. |
49.12500 |
Likely 49.125 MHz nominal frequency | Ordering-code interpretation; verify against SiTime’s configuration record or authorized listing. |
A comparable SiTime AI-44-33E5 part page supports the 3.3-V, industrial-grade and 7.0 × 5.0 mm-with-pad interpretations, but it is a different ordering code. Those fields should not be silently transferred to the E4 part.
Crashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minuteWindows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstall#1 Best Overall
SiT9001 family specifications
The following are family-level capabilities from the SiTime datasheet. They are not all confirmed settings for SIT9001AI-44-33E4-49.12500.
| Parameter | SiT9001 family information | Qualification |
|---|---|---|
| Output frequency | 1–200 MHz | Family range; exact code likely indicates 49.125 MHz. |
| Supply options | 1.8 V, 2.5 V, 3.3 V | The requested code likely indicates 3.3 V; verify exact configuration. |
| Stability options | ±25, ±50 or ±100 ppm | The grade for this exact code is not established. |
| Temperature options | −20 to +70 °C or −40 to +85 °C | Industrial range is probable for AI, but confirm the suffix decode. |
| Package options | 2.5 × 2.0, 3.2 × 2.5, 5.0 × 3.2 or 7.0 × 5.0 mm | The 44 field may indicate 7.0 × 5.0 mm with pad; exact package is unconfirmed. |
| Output load | Maximum normal load capacitance 15 pF | Family condition; optional higher-drive programming supports up to 30 pF and is not automatic. |
| Rise/fall time | Typical 1.0 ns, maximum 1.5 ns | Specified with a 15-pF test load; not an unconditional board-level guarantee. |
| Power-up | Maximum 10 ms | From minimum supply voltage to first cycle under the datasheet’s no-runt-pulse condition. |
| Standby current | Typical 30 µA, maximum 50 µA | Applies to the standby configuration. |
| 3.3-V operating current | 27 mA at 30 MHz and 15-pF load; 34 mA at 125 MHz and 15-pF load | Datasheet test conditions; do not extrapolate directly to this exact SKU. |
| Cycle-to-cycle jitter | 22 ps typical, 29 ps maximum | 3.3-V family figure under the listed 133.33-MHz test condition, not a measurement at 49.125 MHz. |
For the 3.3-V family option, the datasheet gives a 2.97–3.63 V operating range. It specifies 45–55% duty cycle from 1 to 75 MHz and 40–60% from 75 to 200 MHz. Rise/fall, duty-cycle and jitter limits depend on stated test conditions and should not be treated as guaranteed across every load, supply, frequency and spread setting. The datasheet also lists 2,000 V ESD and MSL1 at 260 °C.
Pinout and circuit considerations
The SiT9001 family uses a four-pin interface. Confirm the package drawing and pin orientation for the exact configuration before laying out or replacing a part.
| Pin | Family function |
|---|---|
| 1 | Programmable ST/OE/SD control pin |
| 2 | GND |
| 3 | SS_OUT clock output |
| 4 | VDD |
The shared control pin can be factory-configured as standby (ST), output enable (OE), or spread disable (SD). In OE mode, high or open allows clock output and low makes the output high impedance. In standby mode, low stops the oscillator and leaves a weak pull-down behavior. In SD mode, high or open enables spread while low disables it. The exact requested SKU’s mode is unknown; do not wire pin 1 on the assumption that it is OE. The datasheet recommends a pull-up below 10 kΩ between the control pin and VDD in high-noise environments.
- Connect pin 2 to a low-impedance ground and pin 4 to the verified supply option.
- Route pin 3 as a clock signal and account for the family’s standard 15-pF maximum load condition.
- Check the exact control-pin programming before tying pin 1 high, low or open.
- Keep supply noise and return-current paths controlled. Spread spectrum can reduce certain EMI peaks, but it does not correct poor clock routing or grounding.
What spread spectrum means for the clock
SiT9001 supports down-spread and center-spread modulation with programmable triangular profiles. The exact spread percentage and profile encoded by E4 are not established here. SiTime’s family page describes the family options; a comparable AI-44-33E1 part page illustrates that spread settings are part-specific.
- Down spread varies the instantaneous clock below the nominal carrier.
- Center spread varies frequency around the nominal carrier.
- The code’s likely nominal 49.125 MHz is not the frequency of every individual clock cycle when modulation is active.
- Frequency-counter readings can depend on gate time, modulation profile and measurement method.
Spread spectrum is an EMI-management technique, not a precision-timing improvement. Confirm that the receiving PLL, serializer, ADC, RF stage, clock monitor or other timing-sensitive input accepts the programmed modulation. Do not infer that spread can be disabled unless the exact control-pin configuration supports it.
Is it suitable for your design?
Potentially suitable
- The system needs a single-ended clock and its nominal frequency is confirmed as 49.125 MHz.
- The board uses the verified supply option and the receiving input tolerates spread-spectrum modulation.
- The actual package and pinout match the footprint, and the selected stability grade meets system limits.
- The design can accept a mature component whose family is not recommended for new designs, with an explicit supply plan.
Likely a poor fit
- The application requires an unmodulated precision reference or has strict phase-noise, deterministic-jitter or modulation limits.
- The receiver requires a differential clock such as LVDS, LVPECL, HCSL or CML rather than this family’s single-ended output.
- The system requires automotive qualification or operation to −40 to +125 °C; those conditions are not established for this part.
- The standard load exceeds 15 pF and no factory-approved higher-drive configuration has been confirmed.
- The design depends on a small footprint: the likely 7.0 × 5.0 mm interpretation of code 44 is not verified and may not suit it.
Lifecycle, availability and replacement
SiTime labels the SiT9001 family Not Recommended for New Designs and identifies SiT9005 as its replacement. That is a lifecycle direction, not proof that SiT9005 is a drop-in substitute. Current stock, last-time-buy status, sample availability and standard production orderability for the exact E4 code are not established by the family page.
SiT9005 is listed as a spread-spectrum oscillator family with a 1–141 MHz range, but the exact frequency and behavior must be checked for the proposed replacement. Compare the package, pinout, supply range, control-pin polarity and function, spread profile, stability, temperature grade, startup behavior and load requirements before approving a change. The SiT9005 example page is SiTime’s SiT9005 listing.
Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Scan for outdated or missing drivers - takes under a minute3Repair Windows errors before they cause bigger problemsOther alternatives depend on the design constraint. A fixed-frequency MEMS oscillator may suit a receiver that cannot tolerate modulation, but will not provide the same spread-spectrum EMI behavior. A quartz oscillator may be attractive where phase noise, aging or stability dominates, but can differ in footprint and startup or environmental behavior. A differential oscillator requires compatible receiving circuitry and is not a direct substitute for a single-ended output.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How to verify the exact ordering code
- Open SiTime’s SiT9001 family page and use its part-number decoder, parametric search, cross-reference or support links.
- Submit the full string
SIT9001AI-44-33E4-49.12500to SiTime or an authorized distributor and request written confirmation of nominal frequency, voltage, stability, spread profile, control-pin mode, package and temperature grade. - Ask for current lifecycle and supply status, including whether the code is orderable, custom, obsolete or distributor-held, and whether a successor configuration is available.
- Before approving a substitute, compare its datasheet and package drawing against the schematic, PCB footprint, receiving-device clock limits and EMI requirements.
- Validate the chosen part in the actual circuit, including startup, clock integrity and EMI behavior. A frequency match alone does not establish functional equivalence.
The family page provides routes for sample requests and sales contact; the comparable official AI-44 part page shows the type of manufacturer listing that can establish configuration details. A neighboring SKU is useful for comparison, not a substitute for confirmation of the E4 code.
Quick Recap
Troubleshooting checks
- No clock output: Check VDD and ground, startup allowance, pin orientation and whether the programmed control-pin mode is holding the device in standby or disabling output.
- Output appears high impedance: If the pin is configured as OE, verify its logic level; low disables the output. Confirm that the SKU is actually programmed for OE before applying this diagnosis.
- Frequency reading differs from 49.125 MHz: Confirm the exact nominal frequency and spread setting. Modulation and counter gate time can change the displayed reading.
- Excessive edge distortion or timing variation: Check output loading, probe capacitance, supply noise and receiver input requirements. The 15-pF figure is the normal family load condition.
- EMI does not improve: Verify that spread is enabled and that the selected profile is appropriate; also inspect layout, return paths and coupling. Spread spectrum does not eliminate layout-related emissions.
- Startup or intermittent operation: Verify supply ramp and voltage, control-pin state and load. The family’s maximum 10-ms power-up figure has defined datasheet conditions.
- Part will not fit: Compare the exact body dimensions, pads and pin numbering against the board. The 7.0 × 5.0 mm size associated with a comparable code 44 listing remains an inference for this part.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
