Central Semiconductor Corp 2SC1815 PBFREE
Full Technical Specifications
9 Parameters| Parameter / Attribute | Specification / Value |
|---|---|
| FET type | NPN |
| Voltage - collector emitter breakdown | 50 V |
| Current - collector (Ic) | 150 mA |
| Current - collector cutoff | 100nA (ICBO) |
| DC current gain (hFE) (Min) @ ic, vce | 70 @ 2mA, 6V |
| Power - max | 400 mW |
| Frequency - transition | 80MHz |
| Package | Bulk |
| Vce saturation (Max) @ ib, ic | 250mV @ 10mA, 100mA |
Need Stock or a Drop-in Second-Source for 2SC1815 PBFREE?
Package: TO-92 · Pin-compatible replacements with immediate Shenzhen spot stock
The 2SC945 / 2SA733 pair is the Japanese-standard small-signal transistor of a generation of industrial controls, audio equipment and instruments - and it remains a daily repair item in Chinese production too, where the shorthand names C945 and A733 are stencilled on half the boards. Supply is continuous through second-source fabs, but three naming systems collide on this part: the C945 shorthand, the rank letters (O / Y / GR / BL), and the Japanese E-C-B pin order that is the mirror of the European C-B-E parts people try to substitute.
Verified Pin-Compatible Replacements (4 verified alternatives)
The Documented Audio-Grade Successor
Shenzhen Spot Stock (24-48h Dispatch)
Same 50V / 150mA class as the 2SC945 with the same E-C-B lead order and the same rank system (O / Y / GR / BL), widely treated as the replacement part for the C945 in repair literature.
VCEO 50V; IC 150mA; Ptot 250mW class; low-noise ranks available for audio front ends.
The PNP Half of the Audio Pair
Shenzhen Spot Stock (24-48h Dispatch)
The PNP complement used with the 2SC1815 in the same way the 2SA733 pairs with the 2SC945: -50V / -150mA, E-C-B order.
VCEO -50V; IC -150mA; same rank system.
Registered Western Type Number
Shenzhen Spot Stock (24-48h Dispatch)
onsemis registered version of the 2SC945: same 50V / 150mA ratings and same E-C-B lead order, with full datasheet documentation.
VCEO 50V; IC 150mA; documented hFE bins (O / Y / GR).
Electrically Similar, Physically Mirrored
Shenzhen Spot Stock (24-48h Dispatch)
The European small-signal NPN at similar ratings (45V / 100mA, higher gain) - but the TO-92 lead order is C-B-E, the reverse arrangement of the Japanese E-C-B.
VCEO 45V versus 50V on the C945 - one grade down.
Buyer & Quality Checklist for Sourcing Alternatives
- The pin order is the whole game on this family: Japanese small-signal TO-92 (2SC945, 2SA733, 2SC1815, 2SA1015) is E-C-B; European (BC547) is C-B-E; American (2N3904) is E-B-C. Three standards, one package, zero socket compatibility by default.
- Ranks matter in analog positions: O / Y / GR / BL select ascending hFE windows. Audio front ends were designed around GR or BL parts; a general-purpose replacement can change noise and bias.
- In differential pairs and push-pull stages, replace NPN and PNP together (2SC945 with 2SA733, or the 1815 / 1015 upgrade pair) from one lot.
- The 2SC945 is 50V / 150mA - do not use it where the original was a 2SC1815 with margin added, and never in driver positions rated above 150mA.
- For equipment with paper documentation (Japanese industrial gear especially), the KSC945C / KSA733 registered equivalents keep the paperwork chain intact.
Frequently Asked Technical Questions
Q: Is C945 the same as 2SC945?
A: Yes - C945 is the common shorthand for 2SC945 in schematics and BOMs (the 2S prefix is dropped). Same part, same ratings, sometimes printed that way on the body.
Q: Can I replace 2SC945 with BC547?
A: Electrically similar, physically mirrored: the BC547 lead order (C-B-E) is the reverse of the 2SC945 (E-C-B). A straight swap transposes emitter and collector. Either re-form the leads or use the native E-C-B parts (2SC1815, KSC945C).
Q: What replaces the 2SA733 in audio gear?
A: The 2SA1015 is the standard continuation in the same E-C-B package and rank system; the KSA733 is the registered Western equivalent. Match the rank and keep it paired with the corresponding NPN.