1. Saturation Voltage (Vce(sat)): The typical saturation voltage of the CMPT491E (400mV @ 1A) is lower than that of the ZXTN2038FTA (500mV @ 1A). Under the same load current, the CMPT491E exhibits lower power dissipation and reduced heat generation when operating as a switching transistor, resulting in slightly higher system efficiency. 2. DC Current Gain (hFE): The minimum gain of the CMPT491E (200) is twice that of the ZXTN2038FTA (100). To drive the same collector current, the CMPT491E requires a lower base drive current, which relaxes the demands on the preceding drive circuitry. This facilitates design simplification or reduces power consumption at the control stage. 3. Operating Temperature Range: The CMPT491E features a lower junction temperature (Tj) limit of -65°C, compared to -55°C for the ZXTN2038FTA. This makes the CMPT491E suitable for industrial or automotive electronic environments with stricter low-temperature reliability requirements, while no difference is observed in general commercial applications. 4. Cut-off Current Specification: The CMPT491E explicitly specifies ICBO (collector-base cut-off current), whereas the ZXTN2038FTA does not. This reflects the rigor of the CMPT491E datasheet, although both parts share the same numerical value, resulting in negligible practical impact.