Yes, you can generally replace the B647 with the B649, as they are quite similar in terms of their specifications. Here's a quick comparison of the two:
Just make sure that the application doesn't exceed the 150mA current limit and the 500mW power dissipation, and you should be good to go.
Comparison of B647 and B649:
| Specification | B647 | B649 |
|---|---|---|
| Type | PNP | PNP |
| Collector-Emitter Voltage (Vce) | 80V | 80V |
| Collector-Base Voltage (Vcb) | 80V | 80V |
| Emitter-Base Voltage (Veb) | 5V | 5V |
| Maximum Collector Current (Ic) | 150mA | 150mA |
| Power Dissipation (Pd) | 500mW | 500mW |
| Gain (hFE) | 110 - 320 | 110 - 320 |
| Frequency Response (fT) | 100 MHz | 100 MHz |
| Package Type | TO-92 | TO-92 |
Key Points:
- Voltage Ratings:
Both the B647 and B649 have the same voltage ratings (80V), so there’s no issue with voltage handling. - Current Ratings:
They both handle 150mA of current, which is suitable for low-power applications. This should be fine as long as your circuit doesn’t exceed this current. - Frequency Response:
Both transistors have a 100 MHz frequency response, meaning they can both be used in high-frequency applications without a problem. - Power Dissipation:
Both can dissipate 500mW of power, so as long as your circuit stays within this limit, there shouldn’t be any thermal issues. - Package Type:
Both are in the TO-92 package, so they have the same form factor and pinout.
Conclusion:
You can replace the B647 with the B649 without any major issues in terms of performance (MHz, current, voltage, etc.). They are very similar and are interchangeable in circuits where these low-power, high-frequency characteristics are required.Just make sure that the application doesn't exceed the 150mA current limit and the 500mW power dissipation, and you should be good to go.
