Signal diode (1N4148)
1N4148 · Small-signal switching · 0.3 A · 100 V
Try it on the benchThe lab drops it on an empty bench and opens its datasheet card.
Typical part: 1N4148
Pins
- Anode
- Cathode (band)
Ratings and limits
| Peak inverse voltage | 100 V |
|---|---|
| Forward current | 300 mA (avg) |
| Reverse recovery | 4 ns |
How to use it
Fast small-signal switching: logic, clamping inputs, flyback on small relays.
Lessons and builds that use it
- RL transient
- Inductive load and the flyback diode
- Diode clipper and clamper
- Precision rectifier (superdiode)
- Light-activated switch with relay
- Charge-pump inverter: a negative rail
- Testing diodes and transistors with a meter
- Automatic emergency light (build)
- 555 delay-off timer with relay (build)
- PWM fan or LED dimmer (build)
- 65 W USB-C PD charger from scratch: mains flyback (UC3844, 800 V MOSFET, PQ2625 transformer), TL431 + PC817 feedback, PD controller (build)
- Real device: phone charger, 220 V AC wall to 5 V USB (build)
- Real device: laptop charger, 220 V AC wall to 20 V with PFC (build)
- Temperature-controlled fan (build)