Transistor Datasheet Better — C1124
| Parameter | Value | The Real-World Meaning | | :--- | :--- | :--- | | | 60V | Don't put more than 60V between C and B. Safe for 48V rails. | | Collector-Emitter Voltage (VCEO) | 30V | Critical: This is lower than Vcbo. Do NOT run 60V here. | | Emitter-Base Voltage (VEBO) | 5V | Keep base drive low. | | Collector Current (IC) | 100mA | Low power. Not for drivers or outputs >1W. | | Power Dissipation (Pc) | 2.5W | Use a small heatsink above 1W continuous. | | Gain (hFE) | 40 – 240 | Highly variable by batch. Design for the low end (40). | | Transition Frequency (fT) | 250 MHz (min) | Why it's special: Works well up to ~150 MHz. |
On the original C1124, gain drops from 150 at 100mA to 40 at 2A. A "better" design uses a transistor that maintains a gain of at least 50 up to 3A (e.g., TIP31C). c1124 transistor datasheet better
The C1124 had poor thermal transfer. A "better" transistor will have a lower RθJA, meaning it stays cooler for the same power dissipation. | Parameter | Value | The Real-World Meaning
When you are repairing vintage electronics, audio amplifiers, or switching power supplies, you will eventually come across the . This Japanese NPN epitaxial silicon transistor (often marked as 2SC1124 ) was a workhorse of the 1980s and 1990s. However, if you are reading this article, you have likely run into a common problem: The original datasheet is hard to read, the part is obsolete, or you need a better performing component. Do NOT run 60V here
