Datasheet - Up0104s

The uP0104 is commonly housed in industry-standard packages such as the SOT-89, SOT-223, or TO-92. The standard pinout for the SOT-223 package is defined as follows:

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.

The UP0104S is a dual synchronous buck PWM controller designed specifically for low-output-voltage, high-current DC-DC conversion. Manufactured originally by uPI Semiconductor (UniPower Integrated Circuit), this IC provides two independent regulated outputs or can be configured for a single high-current output using two interleaved phases. Up0104s Datasheet

Beware of fake or incomplete "datasheet" websites that only provide a pinout without electrical tables. To obtain the genuine UP0104S datasheet (revision 1.2 or later), use these sources:

  • Direct PDF Download: Search for file name UP0104S_DS_V1.2.pdf.

    • Pro Tip: Many online "datasheets" for the UP0104S are actually cross-references to the RT8101 or ISL6545. Always compare the pinout diagram. If it doesn't show 14 pins, it's the wrong document. The uP0104 is commonly housed in industry-standard packages

    The uP0104 is a high-performance, low-dropout voltage regulator designed to maintain a stable output voltage with a minimal input-output differential voltage. It is typically available in fixed voltage versions (e.g., 3.3V, 5.0V) and features an internal current limiting circuit and thermal shutdown protection. Its primary use case is converting higher DC voltages (such as from a battery or wall adapter) into stable logic-level voltages for microcontrollers and sensors.

    To use the UP0104S safely, you must respect the limits defined in the datasheet. Exceeding these values will cause immediate destruction of the IC. Direct PDF Download: Search for file name UP0104S_DS_V1

    | Symptom | Likely Cause | Datasheet Checkpoint | | :--- | :--- | :--- | | No output, VCC present | IC in UVLO or disabled | Measure EN1/EN2 (Pins 13 & 5). Must be >2.0V. Check VCC >4.3V (Pin 4). | | Output voltage too low | Feedback divider wrong or output short | Verify FB pin voltage (Pins 1 or 14). Should be exactly 0.8V. If lower, output is shorted or divider is incorrect. | | MOSFETs burning hot | Cross-conduction or wrong frequency | Check UGATE and LGATE dead-time (requires oscilloscope). Replace with matched MOSFETs from datasheet spec. | | Intermittent startup | SS capacitor leakage or unstable COMP | Inspect the soft-start capacitor (Pin 3 for Ch2, shared for Ch1). Leakage here prevents ramp-up. |