Direct sibling chips from uPI Semiconductor with matching electrical behavior.
According to manufacturer specifications and technical footprints cataloged on engineering networks like Veswin Electronics and Jotrin Electronics , the uP0104S balances tight voltage regulation with an industrial-grade thermal threshold.
If you are repairing a device and see a small 3-pin or 8-pin chip marked with "UP0104," "uP0104," or "0104s," you have found your regulator. In many cases, failure of this chip results in the device failing to "power on" or exhibiting "no display" symptoms on a GPU, as the logic chips aren't receiving their required voltage. Summary Table Typical Value LDO Linear Regulator Max Input Current Output Package SOT-223 / SOP-8 Efficiency High (for Linear) Up0104s Datasheet
| Symptom | Likely Cause | Troubleshooting Steps | | :--- | :--- | :--- | | | Lack of Enable (EN) signal | Measure voltage on the EN (Enable) pin. It should be high (~3-5V) to activate the IC. | | Output Voltage Too Low | Faulty Feedback Network | Calculate expected Vout using the Vout = 0.8V * (R1+R2)/R2 equation. Check the FB (Feedback) resistors if the actual output doesn't match. | | Output Short Circuited | Overcurrent Condition | Check for a short circuit to ground on the output pin, as the IC's overcurrent protection may trigger, shutting down the output. | | Excessive Heat | Overload or Internal Fault | Check the current draw on the output. For linear regulators, heat is normal but should be within spec (temp range -40°C to +105°C). | | Complete Lack of Output | Input Power Missing | Verify that the correct input supply voltage is present on the VIN pin. | | Physical Damage | Catastrophic Failure | Look for visible signs of damage like cracks or burns on the IC itself. |
Up0104s Datasheet: Comprehensive Guide to the uPI Semiconductor Linear Regulator Direct sibling chips from uPI Semiconductor with matching
The uP0104 is a linear regulator, meaning it dissipates power as heat. The power dissipation ($P_D$) is calculated as: $$P_D = (V_in - V_out) \times I_load$$ For example, regulating 12V down to 5V at 500mA results in 3.5 Watts of heat dissipation. In such cases, the SOT-223 package alone may be insufficient, and an external heatsink or copper plane on the PCB is required.
Drives internal power rails inside mobile smartphones, digital cameras, and tablets. In many cases, failure of this chip results
The performance of the uP0104 is defined by the following typical parameters (assuming a 5V output variant at 25°C):
The uP0104S is deployed across major electronics industries where stable, sub-2V power rails are mandated. Common Industry Deployments