SPX5205M5-L-1-8/TR SPX5205M5 R1B DD8F 1.8V LDO Voltage Regulator IC

SPX5205M5-L-1-8/TR (R1B / DD8F) 1.8V LDO Voltage Regulator – SOT-23-5 Hashboard Repair

The SPX5205M5-L-1-8/TR (board markings R1B or DD8F) is a 150mA low-noise LDO regulator in a SOT-23-5 SMD package, configured for a fixed 1.8V output. It is used on the auxiliary 1.8V bias rails of various ASIC miner hashboards, where a clean, low-noise reference is needed for analog blocks. Failure mode is usually output-stuck-at-rail or thermal shutdown after the small package overheats.

Where the SPX5205M5 Sits on the Board

The 1.8V rail it produces typically feeds level translators, sensor reference inputs, or oscillator buffers on the hashboard. Because it is a linear LDO, the rail has very low ripple — important for clock-domain stability. When this regulator fails, the dependent block goes silent and the controller logs an initialisation error or the chip-count drops by exactly the chips fed by that domain.

Replacement Procedure

Pre-heat the board to 130-150°C. Remove the failed SPX5205M5 with hot air at 320°C using a small precision nozzle, taking care not to disturb the surrounding 0402 passives. Clean the pads with flux and braid. Place the new chip with pin 1 aligned to the silkscreen mark, reflow at 320°C for 8-12 seconds. Bench-test the 1.8V rail with the board powered through a current-limited supply, then verify chip count via the controller fixture before reassembly.

SPX5205M5-L-1-8/TR Specifications

Related 1.8V LDO Regulators

• LN1134A182MR 4VK4 1.8V LDO – Antminer Hashboard
• SGM2036S 1.8V LDO – Avalon 1446 / 1466
• ME6214C18M5G 1.8V LDO – Innosilicon T1
• RS3236-1.8YF5 1.8V LDO – Whatsminer Control Board

Stocking SPX5205M5 for a hashboard repair line? Contact us at contact@lys-sz.com for tray-quantity pricing. Worldwide shipping from our Shenzhen warehouse.