BD137 transistor
BD137 transistor electrical specification
- BD137 is an NPN silicon epitaxial planer transistor device
- Collector to emitter voltage (VCE) is 60V
- Collector to base voltage (VCB) is 60V
- Emitter to base voltage (VEB) is 5V
- Collector current is 5A
- Pulsed collector current is 3A
- Base current is 5A
- Power dissipation is 5W
- DC current gain is 40 to 250hFE
- Junction temperature is between -55 to 150℃
- Collector to emitter saturation voltage (VCE (SAT)) is5V
BD137 PINOUT
| Pin Number | Pin Name | Description |
| 1 | Emitter | Current flows through the emitter |
| 2 | Collector | Current flow through the collector |
| 3 | Base | The base terminal is used to trigger the transistor |
BD137 package
BD137 MEDIUM power transistor has TO-126/SOT-32 package, it is a three-terminal through-hole device package.
TO-126.SOT-32 is made of epoxy material which is good for heat resistance capability and provides compactness for the component.
TO-126 is a smaller package that is very useful for making small-sized circuits and also it has the provision to attach a heat sink with it.
BD137 transistor specification description/ application note:
Here in this section, we explain the electrical specifications of the BD137 transistor, this much specific explanation is good for a better understanding of the device.
Voltage specs
The terminal voltage specifications of the BD137 transistor are a collector-to-emitter voltage is 60V, a collector-to-base voltage is 60V, and an emitter-to-base voltage is 5V.
The collector-to-emitter saturation voltage value of the BD137 transistor is 0.5V, it is the switching voltage of the device at applications.
The voltage specifications of the BD137 transistor indicate it is a medium power device which having power switching and charger applications.
Current specs
The collector current value of the BD137 transistor is 1.5A and the pulsed collector current value is 3A, the current value of the device shows its maximum load capacity.
The base current value of the BD137 transistor is 0.5A, it is the switching current value of the device.
The current value specifications of the BD137 transistor show that, it had power switching and battery charger applications.
Dissipation specs
The power dissipation value of the BD137 transistor is 12.5W, this value mainly depends on the device package.
Current gain specs
The DC current gain value of the BD137 transistor is 40 to 250hFE, the gain value is important for applications like amplifier and charger circuits.
Maximum temperature
The junction and storage temperature value of the BD137 transistor is -55 to +150℃.
BD137 DATASHEET
If you need the datasheet in pdf please click this link
BD137 equivalent
BD137 medium power transistor has equivalent devices such as BD230, BD349, BD167, BD177, BD787, MJE225, BD138, and 2SC51171S, each of these transistors have the same set of electrical specifications, so we can use them as the equivalent of BD137 device.
Important specifications based on power handling circuits are voltage, current, DC gain, and power dissipation, so we need to check and verify them before the replacement process.
The PINOUT details specs are important for these kinds of applications, so check those at each transistor, because it is very important at the circuit level.
BD137 complementary
BD138 PNP transistor is the complementary pair of BD137 NPN transistor devices, each of them had the same and opposite electrical specifications, we can use them at circuits like push-pull circuits and Darlington pair circuit applications.
BD137 SMD equivalent
BSP55 (SOT-223) SMD transistor is the SMD equivalent of the BD137 transistor, other than power dissipation spec, almost all the electrical specifications are the same for this device.
BD137 vs BD139 vs BD230
Here in the table below we listed the electrical specifications of BD137, BD139, and BD230 transistors, this comparison is very helpful for a better understanding of the transistors for circuit making and replacement process.
| Characteristics | BD137 | BD139 | BD230 |
|---|---|---|---|
| Collector to emitter voltage (VCE) | 60V | 80V | 80V |
| Collector to base voltage (VCB) | 60V | 80V | 100V |
| Emitter to base voltage (VEB) | 5V | 5V | 5V |
| Collector to emitter saturation voltage (VCE (SAT)) | 0.5V | 0.5V | 0.8V |
| Collector current (IC) | 1.5A | 1.5A | 1.5A |
| Pulsed collector current (ICM) | 3A | 3A | 3A |
| Base current (IB) | 0.5A | 0.5A | 1A |
| Power dissipation | 12.5W | 12.5W | 12.5W |
| Junction temperature (TJ) | -55 to +150°C | -55 to +150°C | -65 to +150°C |
| Transition frequency (FT) | - | - | 125MHz |
| Gain (hFE) | 40 to 250hFE | 40 to 250hFE | 40 to 250hFE |
| Package | TO-126/SOT-32 | TO-32 | TO-126 |
BD137 applications
- Audio amplifier circuit
- Driver applications
- Medium power linear and switching applications
- Battery charger circuits
- Power supply circuit
- Darlington pair circuit
- High-fidelity amplifier circuit
- Telecommunication circuits
- General processor applications
Graphical characteristics of BD137
The figure shows the DC current gain characteristics of the BD137 transistor, the graph plots with DC current gain vs collector current.
At constant collector-to-emitter voltage values, the DC current gain increases from a particularly high value and increase towards a peak, and dip down to the lowest value with respect to the collector current value.
The figure shows the collector-to-emitter saturation voltage characteristics of the BD137 transistor and the graph plots the collector-to-emitter saturation voltage vs collector current.
At two different collector current values, the saturation value increases constantly and becomes infinite at the end.
The figure shows the safe operating area characteristics of the BD137 transistor, the graph plots with collector current, collector-to-emitter voltage, and switching speed.
