BC337 - onsemi
Full Technical Specifications
12 Parameters| Parameter / Attribute | Specification / Value |
|---|---|
| Mounting | Through Hole |
| FET type | NPN |
| Voltage - collector emitter breakdown | 45 V |
| Current - collector (Ic) | 800 mA |
| Current - collector cutoff | 100nA |
| DC current gain (hFE) (Min) @ ic, vce | 100 @ 100mA, 1V |
| Power - max | 625 mW |
| Frequency - transition | 210MHz |
| Operating temperature | -55°C~150°C(TJ) |
| Package | Bulk |
| Case | TO-226-3, TO-92-3 (TO-226AA) |
| Vce saturation (Max) @ ib, ic | 700mV @ 50mA, 500mA |
Need Stock or a Drop-in Second-Source for BC337?
Package: TO-92 · Pin-compatible replacements with immediate Shenzhen spot stock
BC547 is the European analog of the 2N3904: a 45V / 100mA NPN in TO-92 that is ubiquitous in industrial repair, instrumentation and teaching labs. It remains in mass production, and supply is not the problem - the naming is. The gain group (A / B / C) is part of the orderable number, and the North American part that looks equivalent, the 2N3904, is wired differently. Substitution traps, not availability, decide whether a repair works.
Verified Pin-Compatible Replacements (4 verified alternatives)
Same Part, Gain-Group Matched
Shenzhen Spot Stock (24-48h Dispatch)
Same die at gain group B: hFE 200-450 at 2mA. The suffix selects the current-gain bin - A is 110-220, B is 200-450, C is 420-800.
VCEO 45V; IC 100mA; Ptot 500mW; fT 300MHz class.
Repair-Grade Upgrade with the Same Sockets
Shenzhen Spot Stock (24-48h Dispatch)
Same 45V family and the same TO-92 C-B-E pinout, but rated 800mA instead of 100mA - the classic upgrade when a BC547 has failed hot.
VCEO 45V; IC 800mA; Ptot 625mW; hFE 100-630 by group.
SMD Form of the Same Die
Shenzhen Spot Stock (24-48h Dispatch)
The surface-mount BC547B: 45V, 100mA, gain group B, in SOT-23.
VCEO 45V; IC 100mA; Ptot 250mW in SOT-23 (mind the smaller thermal budget).
Ubiquitous but Pin-Reversed
Shenzhen Spot Stock (24-48h Dispatch)
60V / 200mA small-signal NPN with different gain characteristics: hFE 100-300 at 10mA versus the BC547 window at 2mA.
VCEO 40V (2N3904 rating is 40V VCEO / 60V VCBO); IC 200mA; Ptot 625mW.
Buyer & Quality Checklist for Sourcing Alternatives
- Read the full orderable number: BC547 versus BC547A / B / C selects the current-gain bin. In analog stages a wrong group shifts the bias point; in switching it rarely matters.
- The TO-92 pinout trap: BC547 is C-B-E; 2N3904 and 2N2222A are E-B-C. Both are "small-signal NPN", and the sockets are not interchangeable without re-forming leads.
- In SMD, BC847 and MMBT3904 share the same SOT-23 land pattern - check the electrical curve differences, not the footprint.
- For complementary stages, order the PNP partner (BC557 for BC547, BC807 for BC847) in the same gain group and lot so the pair stays matched.
- When a BC547 keeps failing in a driver role, go to BC337 before assuming a circuit fault - the higher current rating is the usual real fix.
Frequently Asked Technical Questions
Q: Can I replace a BC547 with a 2N3904?
A: Electrically they overlap (both small-signal NPN), but the TO-92 pin order differs: BC547 is C-B-E and 2N3904 is E-B-C. Either re-form the leads or accept that a straight drop-in swaps emitter and collector. For a genuine drop-in choose BC337 or the SMD BC847 instead.
Q: What does the letter after BC547 mean?
A: It is the DC current gain group: A = 110-220, B = 200-450, C = 420-800 (measured at 2mA). In switching circuits it rarely matters; in analog gain stages, match the group.
Q: Is BC847 the same as BC547?
A: Yes electrically - the same 45V / 100mA NPN die and gain bins - but in the SOT-23 package. BC847B is the surface-mount BC547B, with a smaller thermal budget to match the smaller body.