2N4037-PBFREE - 40V PNP BJT, 1A, TO-39 | Central Semi
Référence : 2N4037-PBFREE ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $2.95 | $2,95 |
| 10 | $2.55 | $25,50 |
| 100 | $2.05 | $205,00 |
| 500 | $1.75 | $875,00 |
| 1 000 | $1.45 | $1 450,00 |
2N4037-PBFREE Présentation
A PNP BJT (bipolar junction transistor) is a current-controlled semiconductor device whose emitter-base junction is forward biased and collector-base junction reverse biased in active operation. PNP transistors complement NPN devices in complementary symmetry amplifiers, level shifters, and high-side switching topologies, and they sit inside the broader bipolar transistor (BJT) family under discrete semiconductors. The 2N4037 belongs to the legacy 2N-series of metal-can BJTs that became a de-facto standard for medium-power analog circuits from the 1960s onward, valued for repeatable characteristics and second-source availability across multiple vendors.
Key features of the 2N4037-PBFREE include a -60 V collector-base breakdown voltage, 1 A continuous collector current, 60 MHz transition frequency (fT) that supports general-purpose amplifier and switching service, low saturation voltage, and -55C to +150C operating junction temperature range typical of metal-can BJTs. The TO-39 (TO-205AD) hermetic metal package offers mechanical robustness, EMI shielding, and proven long-term reliability for aerospace-grade and industrial-control applications.
Typical applications for the 2N4037-PBFREE include complementary push-pull audio output stages (paired with its NPN complement 2N4036), voltage regulators and series pass elements, analog signal switching, driver stages for relays and solenoids, and general-purpose amplifier circuits. The 1 A collector current and 40 V VCEO also make it a useful building block for legacy industrial control equipment. The 2N4037 family has the complementary NPN 2N4036, and second-source equivalents include 2N5323, BC160, BC161, BC460, and BC461 depending on pinning and parameter tolerance.
When designing with the 2N4037, keep in mind that the TO-39 metal case shares a common collector connection with pinout variations across the 2N-series; verify case and pinout against your schematic before substitution. For switching service, base drive current must be at least 1/10th of the collector current to ensure saturation, and adequate heatsinking is required when total dissipation approaches the 1 W rating.
Alternatives de remplacement direct pour 2N4037-PBFREE — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
2N4036
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
2N5323
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
BC161
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
BC160
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
BC460
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
BC461
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
2N4037-PBFREE Valeurs maximales et caractéristiques électriques
| Type de transistor | PNP Bipolar Junction Transistor (BJT) |
| Boîtier | TO-39 (TO-205AD) metal can |
| Type de montage | Through Hole |
| Polarity | PNP |
| Tension collecteur-base (Vcbo) | -60 V |
| Tension collecteur-émetteur (Vceo) | -40 V |
| Continuous Collector Current (IC) | -1 A |
| Power Dissipation (PD) | 1 W (TO-39 case) |
| Fréquence de transition (ft) | 60 MHz |
| Température de jonction en fonctionnement | -55C to +150C (typical for metal-can BJTs) |
| Terminal Finish | Lead (Pb)-free (PBFREE suffix) |
| RoHS Compliance | Compliant (PBFREE variant) |
| Case Style | TO-39 / TO-205AD / Case 79-04 Style 1 |
Configuration des broches de 2N4037-PBFREE
| Broche 1 | Emitter — PNP emitter terminal |
| Broche 2 | Base — Base control terminal |
| Broche 3 | Collector — PNP collector terminal |
| Broche Case | Collector (case) — Metal case internally connected to collector (typical TO-39 BJT convention); verify with datasheet |
Zone de fonctionnement sûr (DC, Tcase=25C)
Applications typiques
2N4037-PBFREE convient pour 6 applications: Complementary Audio Output Stage, Linear Voltage Regulator Pass Element, Relay and Solenoid Driver, General-Purpose Analog Switching, Legacy Industrial Control Equipment Repair, DC Motor Speed Control.
Complementary Audio Output Stage
The 2N4037-PBFREE pairs with its NPN complement 2N4036 in a class-AB push-pull output stage, where -1 A IC and 60 MHz fT allow direct-coupled drive of low-impedance loads up to a few watts. Placed in the negative-rail path of the push-pull pair, the 2N4037 handles the negative half-cycle while the 2N4036 handles the positive half, minimizing crossover distortion and supporting audio bandwidth up to ~20 kHz. The TO-39 metal-can package also offers excellent thermal coupling to the heatsink, sustaining moderate output power with low thermal resistance. Pairing the 2N4037/2N4036 also provides redundancy-friendly sourcing in pro-audio and hi-fi builds.
Recommandé
Linear Voltage Regulator Pass Element
In legacy linear regulator designs, the 2N4037-PBFREE functions as a PNP series pass element for negative output rails (-5V, -12V, -15V common in op-amp supplies). With -40 V VCEO and -1 A IC handling, the 2N4037 is well matched to supply negative rails of up to -30 V input at moderate load currents. The 60 MHz fT ensures the regulator loop remains stable and the 1 W dissipation rating supports ~100 mA continuous load without active heatsinking. Designers combine the 2N4037 with a Zener reference (e.g., 1N4728) and an op-amp error amplifier for closed-loop regulation. The PBFREE finish ensures the regulator assembly meets RoHS-compliant assembly lines.
Recommandé
Relay and Solenoid Driver
The 2N4037-PBFREE drives 12-24 V relays, solenoids, and small DC actuators directly from logic-level control signals, thanks to its high current gain in DC mode and -1 A collector current. Place the relay coil between the positive supply and the 2N4037 collector; drive the base through a series resistor from a microcontroller or logic gate. The PNP high-side switch topology avoids grounding the load, making it compatible with industrial PLC and automotive 12 V chassis wiring. The 40 V VCEO also tolerates 24 V industrial supply rails with margin. TO-39 mechanical ruggedness is a plus in factory-automation environments where vibration and dust are concerns.
Recommandé
General-Purpose Analog Switching
Use the 2N4037-PBFREE as an analog signal router or selector in multiplexers, sample-and-hold stages, and signal-conditioning front ends. With 60 MHz fT the device passes audio-band and low-MHz intermediate frequencies with minimal distortion, while -1 A IC supports switching of low-impedance signal paths. Place it as a shunt switch across a series resistor for a programmable attenuator, or as a pass element in a multiplexer IC's output stage. The metal TO-39 case provides mechanical stability for vintage test equipment retrofits. Designers must observe the VCEO limit to avoid breakdown on high-amplitude signals.
Recommandé
Legacy Industrial Control Equipment Repair
The 2N4037-PBFREE is a direct lead-free replacement for the legacy 2N4037 used in 1970s-1990s industrial control boards, PLCs, CNC controls, and process instrumentation. The TO-39 footprint and pinout match the original 2N4037, allowing one-for-one PCB swap during repair without layout changes. The PBFREE finish satisfies modern RoHS-required assembly lines, while the electrical character is unchanged from the original part. This application is widely used by maintenance engineers refurbishing Allen-Bradley, Siemens, and ABB control cards where original BJTs have aged out. Stocker 2N4037-PBFREE in your parts library for legacy service work.
Recommandé
DC Motor Speed Control
In linear DC motor speed controllers (e.g., small DC gear motors), the 2N4037-PBFREE handles the PNP half of an H-bridge or a high-side switch leg, modulating average motor voltage via PWM or linear regulation. The -1 A IC supports motors up to ~1 A continuous stall current at -24 V, and the 60 MHz fT supports PWM frequencies beyond the audible range (above 20 kHz) to minimize motor whine. The metal TO-39 package dissipates up to 1 W and can be clip-mounted to a small heatsink for duty-cycled motor service. Bench-tested motor control circuits commonly use the 2N4036 as the complementary NPN for full H-bridge bidirectional control.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour 2N4037-PBFREE — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | 2N4036 | 2N5323 | BC160 | BC161 | BC460 | BC461 |
|---|---|---|---|---|---|---|---|
| Brand | Central Semiconductor | Central Semiconductor | Central Semiconductor | Central Semiconductor | Central Semiconductor | Central Semiconductor | Central Semiconductor |
| Package | TO-39 (TO-205AD) | TO-39 (TO-205AD) - same | TO-39 (TO-205AD) - same | TO-39 (TO-205AD) - same | TO-39 (TO-205AD) - same | TO-39 (TO-205AD) - same | TO-39 (TO-205AD) - same |
| Transistor Type / Polarity | PNP BJT | NPN BJT (complementary, not PNP) | PNP BJT | PNP BJT | PNP BJT | PNP BJT | PNP BJT |
| Lead Free (RoHS) | Yes (PBFREE suffix) | Varies by part number suffix | Varies by part number suffix | Varies by part number suffix | Varies by part number suffix | Varies by part number suffix | Varies by part number suffix |
Principaux différenciateurs
- Same TO-39 case across all named alternatives (vs BC161)
- PNP polarity identical across all substitutes except the NPN complement (vs 2N4036)
- Verified lead-free (PBFREE) finish (vs Standard 2N4037 (non-PBFREE))
Notes de conception
Estimated: at VCE=-10 V and IC=-500 mA, steady-state dissipation is ~5 W, well above the 1 W free-air rating. Mounting the TO-39 metal can to a 100 cm^2 copper PCB area or a clip-on heatsink (theta_SA ~10 C/W) keeps junction rise below 50 C above ambient. For continuous operation above 200 mA, a heatsink is strongly recommended. The metal case shares the collector potential; isolation hardware (mica washer + shoulder washer) is required if the heatsink is not at collector potential.
Recommended: bend the three TO-39 leads with a 90-degree tool to fit a 2.54 mm hole pattern, leaving at least 2.5 mm of case clearance above the PCB for thermal airflow. Use a generous copper pour (>=1 oz, >=100 mm^2) under the case to assist heat spread. Avoid running signal traces beneath the metal case to minimize parasitic coupling; if ground-plane stitching is required, do not rely on the case as a ground return path.
Do not confuse the 2N4037 PNP pinout with the 2N2222/2N2219 NPN TO-39 NPN pinout, which uses base at pin 1, emitter at pin 2, and collector at pin 3. The 2N4037 uses the reverse (emitter at pin 1, base at pin 2, collector at pin 3). Verify pinning with the manufacturer's datasheet diagram before PCB fabrication. Also verify the case-collector connection polarity; on some 2N-series TO-39 BJTs the case is connected to a different pin.
Informations de conformité
PBFREE suffix denotes lead-free terminal finish (RoHS compliant). REACH and halogen-free status should be confirmed via Central Semiconductor's full material declaration (FMD) document. Not AEC-Q100 qualified - the 2N4037 is a general-purpose transistor, not an automotive-qualified part. The 2N4037 die is a legacy 2N-series design with second-source availability from Fairchild and other vendors.
