2N4037 - 40V PNP Power BJT Transistor | Central Semiconductor
Référence : 2N4037 ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $4.2 | $4,20 |
| 10 | $3.78 | $37,80 |
| 100 | $3.35 | $335,00 |
| 500 | $2.95 | $1 475,00 |
| 1 000 | $2.58 | $2 580,00 |
2N4037 Présentation
An PNP bipolar junction transistor is a three-terminal semiconductor device in which a p-type emitter, n-type base, and p-type collector form two back-to-back p-n junctions. Conventional current flows from emitter to collector when the base is pulled below the emitter potential, and the device operates in the active region when the base-emitter junction is forward-biased and the base-collector junction is reverse-biased. PNP BJTs are commonly used as low-side switches, complementary-symmetry push-pull amplifiers (paired with NPN devices), and level shifters in mixed-polarity analog circuits. The 2N-series designation historically indicates a JEDEC-registered part number with widely shared specifications across manufacturers.
Key features of the 2N4037 include a maximum collector-base voltage of 60V, a maximum emitter-base voltage of 7V, a power dissipation rating of 1W (to 25°C case), DC current gain (hFE) typically 40 to 250 depending on collector current, and a transition frequency (fT) of approximately 60 MHz. The TO-39 metal package provides hermetic sealing suitable for military, aerospace, and industrial environments, with three through-hole leads (emitter, base, collector) on standard EIA lead spacing.
The architecture is an epitaxial planar PNP silicon construction, a manufacturing approach where a thin epitaxial layer is grown on the silicon substrate to control minority carrier lifetime and improve switching characteristics versus older alloy-junction designs. The planar passivation process yields stable leakage and gain over temperature, supporting operation from -65°C to +200°C as typical for the TO-39 metal-can family.
Typical applications include general-purpose linear amplifiers, low-frequency switching circuits, complementary-symmetry audio output stages paired with 2N4036 NPN, driver stages for relays and solenoids, voltage regulators, and current sources. The 1W dissipation rating supports small signal-amplifier and modest driver use; high-current applications require discrete heatsinking or the use of a TO-220 equivalent.
When designing with this part, verify the pinout against the datasheet (TO-39 pin order varies by manufacturer and by family). The TO-39 case must be considered in the thermal budget - at 1W dissipation the case-to-ambient thermal resistance typically requires derating above 25°C ambient, and a small clip-on heatsink or thermal compound to chassis is recommended for continuous full-load operation.
This page synthesizes distributor pricing, drop-in alternatives, pinout notes, and practical design guidance not consolidated in the manufacturer datasheet, providing actionable engineering context for component selection.
Alternatives de remplacement direct pour 2N4037 — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec 2N4037 (même facteur de forme et même empreinte) — différant par Continuous Collector Current (Ic), Emitter-Base Voltage (Vebo), Transistor Type, Transition Frequency (fT).
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
2N5323
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
2N4036
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
BC160
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
BC161
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
2N4037 PBFREE
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
2N4037 Valeurs maximales et caractéristiques électriques
| Type de transistor | PNP Bipolar Junction Transistor |
| Material | Silicon (Si), epitaxial planar |
| Polarity | PNP |
| Tension collecteur-base (Vcbo) | 60 V |
| Tension collecteur-émetteur (Vceo) | 40 V |
| Tension émetteur-base (Vebo) | 7 V |
| Continuous Collector Current (Ic) | 1 A |
| Power Dissipation (Pc) | 1 W (TO-39 case, 25°C) |
| Fréquence de transition (ft) | 60 MHz (typical) |
| DC Current Gain (hFE) | 40-250 (depending on Ic) |
| Plage de température de fonctionnement | -65°C to +200°C |
| Boîtier | TO-39 (TO-205AD) metal can, 3-pin through-hole |
| Type de montage | Through Hole |
| Configuration | Single transistor, 3 leads (E, B, C) |
| Compliance | RoHS variant available (PBFREE suffix); TIN/LEAD variant also offered |
Configuration des broches de 2N4037
| Broche 1 | Emitter — Emitter terminal (E) |
| Broche 2 | Base — Base terminal (B) - control input |
| Broche 3 | Collector — Collector terminal (C) and case |
Applications typiques
2N4037 convient pour 7 applications: Complementary-Symmetry Audio Output Stage, Linear Small-Signal Amplifier, Relay and Solenoid Driver, Voltage Regulator Pass Element, Switching Circuit and Signal Conditioning, Current Source and Current Mirror, Legacy and Vintage Equipment Repair.
Complementary-Symmetry Audio Output Stage
The 2N4037 paired with its NPN complement 2N4036 forms a classic complementary-symmetry push-pull output stage for low-power audio amplifiers. The 2N4037's 40V Vceo and 1A continuous collector current suit single-ended Class A or Class AB stages driving a few hundred milliwatts into an 8-ohm speaker. With fT of 60 MHz the device provides ample bandwidth for the audio band and significantly beyond, while the TO-39 metal can offers mechanical ruggedness for hand-wired vintage audio projects and the hermetic seal supports tube-amp-style chassis-mounted builds.
Recommandé
Linear Small-Signal Amplifier
The 2N4037 is well suited as a general-purpose linear amplifier in industrial instrumentation and control circuits. Its DC current gain hFE of 40-250 supports stable biasing in common-emitter or common-collector (emitter-follower) configurations, and its 60V collector-base rating provides significant headroom over the 40V Vceo, allowing inductive kickback transients in relay coils. The hermetic TO-39 package stands up to factory-floor temperature cycling and airborne contamination that would degrade plastic-packaged alternatives, supporting long-life industrial deployments.
Recommandé
Relay and Solenoid Driver
The 2N4037's 1A continuous collector current makes it an effective low-side driver for relays, solenoids, and small DC motors in industrial control. With its 40V Vceo it can switch 24V industrial rails through inductive loads comfortably, providing margin for flyback transients when paired with a freewheeling diode. The PNP polarity is convenient when the driver must be referenced to a positive supply rail, and the TO-39 metal package supports chassis-mounted thermal bonding for sustained 1W dissipation at high duty cycles.
Recommandé
Voltage Regulator Pass Element
In discrete linear voltage regulators and shunt references the 2N4037 can serve as the series pass element when paired with a Zener reference and an error amplifier. The 40V Vceo handles raw 24V industrial bus inputs with substantial margin, and the 1A collector current supports moderate-current regulation for analog subsystems. The PNP polarity suits low-dropout regulator topologies in which the pass element sits between the unregulated input and the regulated output with the emitter delivering current to the load.
Recommandé
Switching Circuit and Signal Conditioning
The 2N4037 is frequently used as a saturated or unsaturated switch in logic-level translation circuits, level shifters, and analog gating stages. With fT of 60 MHz it offers substantially more bandwidth than switching applications strictly require, making it well suited to high-speed analog multiplexers and sample-and-hold front-ends. The hermetic TO-39 package also supports test-and-measurement equipment that must survive years of bench-side thermal cycling.
Recommandé
Current Source and Current Mirror
The matched-pair characteristics of the 2N4037 (when sourced as a complementary 2N4036/2N4037 set) make it a useful building block for discrete current mirrors and precision current sources. The hFE linearity over collector current supports Wilson and Widlar mirror topologies, and the 40V Vceo allows operation across wide compliance ranges. Such mirrors are commonly used in biasing circuits for op-amps and precision references, where the matched NPN/PNP pair from a single-die complementary process minimizes offset.
Recommandé
Legacy and Vintage Equipment Repair
The 2N4037 remains a popular replacement part for repairing vintage analog electronics - tube amplifier front ends, 1970s-era instrument preamplifiers, and classic ham-radio transmitter stages. The TO-39 metal can is a direct mechanical match for original 2N-series sockets, and the part is broadly second-sourced, so repair technicians can maintain period-correct builds without resorting to plastic-packaged modern equivalents. Its tolerance to high ambient temperatures inside chassis-mounted equipment also makes it durable in service.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour 2N4037 — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | 2N5323 | 2N4036 | BC160 | BC161 | 2N4037 PBFREE |
|---|---|---|---|---|---|---|
| Brand | Central Semiconductor | Multiple (2N-series) | Central Semiconductor | Multiple (BC-series) | Multiple (BC-series) | Central Semiconductor |
| Package | TO-39 (TO-205AD) | TO-39 | TO-39 | TO-39 | TO-39 | TO-39 |
| Polarity | PNP | PNP | NPN | PNP | PNP | PNP |
| Vceo | 40 V | 50 V | 40 V | 40 V | 60 V | 40 V |
| Vcbo | 60 V | 75 V | 60 V | 40 V | 60 V | 60 V |
| Ic (Continuous) | 1 A | 2 A | 1 A | 1 A | 1 A | 1 A |
| Power Dissipation | 1 W | 5 W | 1 W | 3.7 W | 3.7 W | 1 W |
| fT (Transition Frequency) | 60 MHz | 30 MHz | 60 MHz | 50 MHz | 50 MHz | 60 MHz |
| RoHS Compliance | Pb-free variant available | Pb-free variant available | Pb-free variant available | Varies by manufacturer | Varies by manufacturer | Yes (RoHS compliant) |
Principaux différenciateurs
- Hermetic TO-39 metal can package availability in production (vs BC160 (plastic package))
- Documented complement pairing on a single datasheet (vs 2N5323 (no documented complement))
- Lead-free RoHS-compliant option from a long-established manufacturer (vs BC161 (varying compliance by source))
Notes de conception
The TO-39 metal can has a junction-to-ambient thermal resistance of approximately 195°C/W without a heatsink. At the full 1W dissipation rating the junction-to-case rise is roughly 75°C, so case temperature must remain below 150°C to keep the junction under its 200°C maximum. For sustained full-load operation the TO-39 case should be thermally bonded to a small clip-on heatsink or to the equipment chassis through thermal compound.
The 2N4037 through-hole TO-39 outline requires three plated through-holes on 2.54 mm (0.1 inch) spacing, matched to the standard metal-can lead footprint. The case tab/flag orientation must match between the 2N4037 PNP and the 2N4036 NPN for shared PCB layouts in complementary stages. For SMD migration, modern equivalents such as MMBT3906 (SOT-23) or BCP51 (SOT-223) provide electrical substitution but require PCB rework - they are not drop-in TO-39 replacements.
Two common pitfalls with the 2N4037 are misreading the pinout and ignoring the Early voltage. Pin assignments for the TO-39 metal can vary between manufacturers of 2N-series parts; always verify against the specific vendor's datasheet before PCB layout. Second, with Vceo of 40V the device cannot be used directly across 48V telecom rails - in those applications consider a higher-Vceo part such as the BC161 (60V Vceo) or a modern MPSA92 (300V) in a different package.
Informations de conformité
The 2N4037 is available in both a RoHS-compliant lead-free finish (2N4037 PBFREE per DigiKey) and a traditional tin/lead finish (2N4037 TIN/LEAD per Mouser). AEC-Q100 automotive qualification is not pursued for this legacy 2N-series industrial part; for automotive designs migrate to AEC-Q100-qualified modern equivalents.
