813RN A0231 Ceramic Crystal Oscillator 25MHZ Avalon 1166pro

813RN A0231 25MHz Crystal Oscillator | SiTime 2520 4-Pin for Avalon 1166pro Hashboard

The 813RN A0231 is a precision 25MHz crystal oscillator in a compact 2.5×2.0mm 4-pin ceramic package — the clock-source IC used on the Avalon 1166pro hashboard to provide the master clock for the A3206 hashing ASICs. Manufactured by SiTime in their 2520-series MEMS oscillator family, the part offers excellent frequency stability across temperature and supply variation.

ASIC hashboards depend on a clean 25MHz clock to drive the on-chip PLLs that generate the multi-GHz hash core clocks. When the master oscillator fails or drifts out of spec, the symptoms cascade through the entire hashboard: chip-detection failures, mismatched hash rates across the chain, or complete board boot failure. Replacing the 813RN A0231 with a fresh part restores the clock distribution and brings the board back into spec.

When to Replace the 813RN A0231

• Hashboard fails to detect chips on the chain — controller reports "0 chips found" while the rest of the board powers up.
• Hashrate drops to zero on one or more hashboards while voltage and current draw look normal.
• Frequency counter measurement shows the 25MHz output drifting or absent on the oscillator's output pin.
• Visible damage on the oscillator — cracked package or burnt marking.
• Hashboard intermittent failures after thermal expansion (warm-up) — the small SMT oscillator is sensitive to micro-cracks from thermal cycling.

Specs and Technical Features

• 25MHz nominal frequency — direct match for Avalon 1166pro hashboard clock spec.
• 2.5×2.0mm 4-pin ceramic package (SiTime 2520) — drop-in for the OEM footprint.
• 1.8V to 3.3V supply voltage range — fits the controller's auxiliary rail without modification.
• ±25ppm frequency stability across the full operating temperature range.
• -40°C to +85°C operating temperature — covers the full mining-deployment envelope.
• Low-jitter CMOS output — clean clock signal for downstream PLL multiplication on the hash ASICs.
• MEMS-based architecture — significantly more shock-resistant than quartz equivalents.

813RN A0231 Crystal Oscillator Specifications

FAQ — 813RN A0231 25MHz Oscillator

Q: How do I test the oscillator before replacing it?
A: Use a 100MHz scope probe (x10) on the oscillator's output pin (pin 3 on standard 2520 pinout) with the board powered up. You should see a clean 25MHz square wave at 0.8x VCC amplitude. No output or distorted output = failed oscillator.

Q: Can I substitute a different 25MHz oscillator?
A: As long as the part shares the same 2.5×2.0mm 4-pin SiTime 2520 footprint, supply voltage range, and frequency stability, electrically yes. Always verify the pinout (CMOS / OE / GND / VDD or alternate) matches before placing.

Q: Rework profile for 4-pin SMD oscillators?
A: Hot-air rework at 320°C with controlled airflow. Apply flux, preheat the board to 100°C, lift with tweezers, place fresh part with pin-1 orientation matching the silk mark, reflow.

Q: Does the replacement need calibration?
A: No — MEMS oscillators ship trimmed to ±25ppm from the factory. No further calibration required.

Q: Bulk pricing for repair shops?
A: Yes — email contact@lys-sz.com for tape-and-reel quantities.

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Avalon 1166pro repair benches stocking 813RN A0231 oscillators in volume? Email contact@lys-sz.com for bulk pricing and matched hashboard repair kits. Worldwide shipping from our Shenzhen warehouse.