BETACollector limit−100 V · absolute VCEO
PNP Darlington power transistor
TIP127 Specifications
Review TIP127 electrical specifications, operating conditions and package details.
Package view
Key specifications
The two-stage PNP connection switches from the positive rail. Match the drive to emitter voltage, budget base current, and use the selected package’s safe operating area and thermal limits.
TO-220 current limit5 A magnitude · absolute
DC gain minimum1000 At specified test points
Junction limit150 °C · maximum
Package details
TIP127G · TO-220AB
| Property | Details |
|---|---|
| Manufacturer | onsemi |
| Part number | TIP127G |
| Package | TO-220AB |
| Connections | 3 pins |
| Mounting | Through-hole |
| Lead pitch | 2.54 mm |
| Package code | 221A style 1 |
| Thermal reference | 65 W at case 25°C; 2 W at ambient 25°C |
Device and package scope
Two documented onsemi selections
Manufacturer specifications 5 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Through-hole | TIP127G · TO-220AB | TIP120/D Rev. 10, June 2024 |
| Surface-mount | MJD127T4G · DPAK | MJD122/D Rev. 16, April 2026 |
| Connection | PNP Darlington · B1, C2, E3 | Metal tab/contact 4 is also collector |
| Construction | Two stages with internal shunt resistors | Approximately 8 kΩ / 120 Ω shown for TIP127 |
| SMD relationship | Documented replacement family | Different ratings and test points; not a footprint-compatible substitute |
No specifications match. Try a parameter name or a unit.
Electrical values below are magnitudes; PNP voltage and current signs reverse.
Absolute limits by package
Individual stress limits, not simultaneous targets
Manufacturer specifications 5 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Collector-emitter / collector-base | 100 / 100 V | Both selections |
| Emitter-base / base current | 5 V / 120 mA | Both selections |
| TO-220 DC / peak collector | 5 / 8 A | Thermal and SOA restrictions apply |
| DPAK DC / peak collector | 8 / 16 A | Different package and pulse conditions |
| Junction / storage | −65 to +150°C | Both selections |
No specifications match. Try a parameter name or a unit.
Do not infer allowable load power from collector-current ratings.
TIP127 electrical characteristics
TC 25°C; pulse ≤300 µs, duty ≤2%
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| hFE minimum | 1000 | IC 0.5 A or 3 A; VCE 3 V |
| VCE(sat) maximum | 2 V / 4 V | IC 3 A / 5 A; IB 12 mA / 20 mA |
| VBE(on) maximum | 2.5 V | IC 3 A; VCE 3 V |
| ICEO maximum | 0.5 mA | VCE 50 V; base open |
| ICBO / IEBO maximum | 0.2 / 2 mA | VCB 100 V / VBE 5 V |
| Small-signal gain minimum | 4 | IC 3 A; VCE 4 V; 1 MHz |
| Output capacitance maximum | 300 pF | PNP; VCB 10 V; 0.1 MHz |
No specifications match. Try a parameter name or a unit.
Gain does not make the on-state voltage drop disappear.
MJD127 electrical characteristics
TC 25°C; separate SMD reference
Manufacturer specifications 8 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| hFE | 1000–12000 at 4 A; ≥100 at 8 A | VCE 4 V |
| VCE(sat) maximum | 2 V / 4 V | IC 4 A / 8 A; IB 16 mA / 80 mA |
| VBE(on) maximum | 2.8 V | IC 4 A; VCE 4 V |
| VBE(sat) maximum | 4.5 V | IC 8 A; IB 80 mA; pulse ≤300 µs, duty ≤2% |
| ICEO / ICBO maximum | 10 / 10 µA | VCE 50 V / VCB 100 V |
| IEBO maximum | 2 mA | VBE 5 V; collector open |
| Small-signal gain minimum | 4 at 1 MHz; 300 at 1 kHz | IC 3 A; VCE 4 V |
| Output capacitance maximum | 300 pF | PNP; VCB 10 V; 0.1 MHz |
No specifications match. Try a parameter name or a unit.
Read each test condition before comparing the SMD and through-hole variants.
Thermal and safe operating area
Case and ambient limits are different
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| TO-220 case / ambient power | 65 W / 2 W | At case / ambient 25°C; derate 0.52 / 0.016 W per °C |
| TO-220 RθJC / RθJA | 1.92 / 62.5°C/W | Maximum |
| DPAK case / ambient power | 20 W / 1.75 W | At 25°C; derate 0.16 / 0.014 W per °C |
| DPAK RθJC / RθJA | 6.25 / 71.4°C/W | Specified minimum land pattern |
| Safe operating area | Use the selected manufacturer curves | Second breakdown and pulse duration also matter |
| Inductive loads | Use a suitable external clamp | The pictured resistor does not store magnetic energy |
No specifications match. Try a parameter name or a unit.
The model artwork is not a heatsink rating.
Positive-side resistor-load switch
Explicit illustrative assumptions
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Emitter / collector load | +12 V / 100 Ω to ground | Use at least a 2 W resistor with thermal margin |
| Buffered driver | 12 V off; 7 V on | Must sink base current; referenced to the emitter supply |
| Base resistor / return | 1 kΩ / 10 kΩ | Return goes to emitter, not ground |
| Assumed drops | |VBE| 1.4 V; |VCE| 1 V | Teaching assumptions, not guaranteed test points |
| Device base current | 3.46 mA | (5−1.4)/1000−1.4/10000 |
| Collector / forced current ratio | 110 mA / 31.8 | (12−1)/100; IC/IB |
| Device / load loss | 0.115 W / 1.21 W | Includes base contribution |
No specifications match. Try a parameter name or a unit.
Use a real level-shifted or buffered control stage; do not connect a low-voltage GPIO directly.
Connections by function
Select a pin for its function, connection guidance and electrical notes.